Wicked vibration, cant seem to kill it

[ThoR294]

Ill go down the list

I had a rebuilt trans off of ebay in the car, so I thought that was it, so i swapped the one that was originally in the car back in, still SAME vibration.

Ive had the stock steel driveshaft balanced, and I had an alum driveshaft in the car out of a 2000 camaro... same vibration.

Had the wheels straightened and I balanced them. Ive had new tires put on as well. STILL a vibration.

New torque arm, set the pinion angle... vibration still there.

Ive had my rear end rebuilt as well, axles are straight, all new pieces in the rear, detroit trutrac posi unit and 3.73s, STILL a vibration.

it happens at around 70+mph, and its really bad when u put the clutch pedal in or put the car in neutral. It feels like the driveshaft is going to fly out of the car. its so bad. I cant figure it out for the life of me. Im so desperate right now. if anyone is around flemington that can help... PM me or email me thor294@comcast.net

Thanks. I want to be able to drive my car over 70 :(

[WildBillyT]

Transmission mount?

[sweetbmxrider]

tranny mount usually results in bangs on acceleration, usually.

pinion angle issue?

where are you feeling the vibration? steering wheel? back of seat? floor? get as specific as you can please.

[ThoR294]

I feel it in the floor really. Pinion angle is set to -2. I have a poly trans mount. its like a BURRRRRRRRRRRRR vibration and its really bad in neutral, and its pretty much gone when the car is in gear accelerating

[WildBillyT]

What happens if you put it in the air with no driveshaft? That will isolate trans/engine vs driveshaft/rear/wheels.

[sweetbmxrider]

definitely a good move. remove it and report back.

[siguy]

Check is the lower rear control arms (if the bushing are bad the axle will move around throwing the pinion angle off ..


this is a long shot (because you said the rear was rebuild but check the pinion yoke on the rear axle (they are knonw to get loose (the crush sleeve) (you need to take the drive-shaft out and move it back in forth to see if its loose.) (you can push up on back of the driver shaft while in but, its easier to see if the crush Bearing is bad if the drive-shaft is out...

[ThoR294]

the vibration was there before the rear was rebuilt too :( literally everything in the rear is new except the axles and the posi unit (I put the locker in a while ago).

the LCAs are like 2 year old BMRs, but Ill check them again.

[siguy]

the vibration was there before the rear was rebuilt too :( literally everything in the rear is new except the axles and the posi unit (I put the locker in a while ago).

the LCAs are like 2 year old BMRs, but Ill check them again.


gezzzz then i am stumped :banghead:also because i have a nasty vibe for a long time and could not figure it out until i check the yoke... please keep me updated iwould really like to know what the issue is ....


Question did you replace the flywheel and clutch when you pulled the trans

[ThoR294]

i resurfaced the flywheel and put a spec stage 2 clutch in it. but why would the flywheel be an issue. the vib doesnt change when i turn the motor off.

[andy78TA]

axles are definately straight? bearings? A long shot but are all the brakes in good working order? Sometimes a brake pad will stick which will cause vibration. It happened in my explorer. It was one of the last things I checked after replacing everything plausable.

edit: brakes probably wouldn't cause the issue if it happens when you are in neutral not moving haha

[WildBillyT]

i resurfaced the flywheel and put a spec stage 2 clutch in it. but why would the flywheel be an issue. the vib doesnt change when i turn the motor off.

So it doesn't go away if you are rolling and the engine is off?

[ThoR294]

So it doesn't go away if you are rolling and the engine is off?

correct

[ThoR294]

axles are definately straight? bearings? A long shot but are all the brakes in good working order? Sometimes a brake pad will stick which will cause vibration. It happened in my explorer. It was one of the last things I checked after replacing everything plausable.

edit: brakes probably wouldn't cause the issue if it happens when you are in neutral not moving haha

friend rebuilt my rear he said they were straight. I have all new stuff in the rear minus the axles themselves and posi unit. brakes not sure ill have to look

[ThoR294]

axles are definately straight? bearings? A long shot but are all the brakes in good working order? Sometimes a brake pad will stick which will cause vibration. It happened in my explorer. It was one of the last things I checked after replacing everything plausable.

edit: brakes probably wouldn't cause the issue if it happens when you are in neutral not moving haha

the vibration is at higher speeds. 70mph+ its real bad. idle nothing

[sweetbmxrider]

i'm kinda getting mixed info but i'd recheck the wheel balance personally. make sure the tires and rims are straight, no shifted belts or real uneven wear.

[JW]

The wheels have no bends or such from hitting any pot holes or curbs?

JW :D

[ThoR294]

The wheels have no bends or such from hitting any pot holes or curbs?

JW :D

haha thats why I got them repaired and repainted. I also double checked them on the tire machine, no runout and the tires are good. 2 brand new tires on the rear... same vibration :( Im almost tempted to ask someone to let me swap wheels but I really dont think that will fix it. ugh i want to kill myself

[andy78TA]

I am in Branchburg and work in Flemington. If you want a second person to come take a look with you and help with the head scratching let me know.

[ThoR294]

i thinki saw u post saying u work at home depot? lol im like 5 min from there

[andy78TA]

Yep I do. I am a full time student in Pennsylvania, but spring break starts tomorrow so I will be home for the week. I am also home about once a month to work.

[wretched73]

Any weird tire wear?

[Mark42]

Check that the rims are hub-centric, meaning that they fit snug on the lip on the rear axle hub. They can be balanced perfect, but if not mounting/centering on the axles, then they will be oob when driving. If they are not OEM, they may also need some hub-centric plastic rings to center them on the axle hubs.

If possible, try swapping wheels/tires with someone who has OEM rims on their F-body just as a test.

[ThoR294]

my rims are OEM

[wretched73]

could the vibration be your torque arm shifting while at top speeds? maybe check that its all square and tight?

[ThoR294]

Stock torque arm, aftermarket torque arm... same vibrartion, everything is tight.

I was thinking maybe both transmissions have a bad tailshaft bushing or something... how would I check that

[Mark42]

How are the rotors? If they have bad corrosion, pieces of the vane in the fronts can rust off, and pieces along the edge can flake off making them oob. Because of their rather small diameter, they won't show vibration until high speeds. Also check the back side of the front rotors to be sure nothing is stuck in the cooling vents that could cause it to be oob.

The rear are a single solid rotor, iirc. But they should be inspected for excessive rusting/flaking along the edges.

Another thing, check the clutch friction disk to be sure it has not lost a chunk of lining.

haha thats why I got them repaired and repainted. I also double checked them on the tire machine, no runout and the tires are good

If one or more wheels were repaired, I would swap on another set of wheels & tires. You don't know if they are oob from welding, and balancing may not eliminate the oob at high speeds, although it will feel balanced at lower highway speeds.

[JL8Jeff]

Doesn't sound like an issue with the trans. Did you check the u-joints, driveshaft play, pull the driveshaft and spin the rear to see if the brakes are grabbing unevenly. See if you can have someone follow you on the highway and watch your rear wheels at 70 mph to see if there is any wobble at all. Are the rotors/wheels seating themself all the way on the axle flange? If there is any rust buildup on the flange the rotors might not seat all the way making it uneven. Definitely try swapping wheels/tires with someone if possible to help eliminate wheel/tire/balancing without spending too much time or money.

[ThoR294]

who wants to swap wheels with me? :O I also removed the whole rear to have it rebuilt... so i put the rotors back on also. but I should check the brakes

[BonzoHansen]

It ain't rotors unless they aren't seated right, and you'd know that by now. Rotate front to rear and see if it changes. If it does you found it if it does not you likley elimiated wheels/tires.

Here, this chart is great.
http://www.tirerack.com/images/tires/vibechart.pdf

[ThoR294]

I put 2 new tires on the back, balanced them and checked them. Same vibration. so I rotated the tires, checked all 4 again, all good... same vibration

[BonzoHansen]

Then tires/wheels are not the issue. Move on to axle runout/bearing play and driveshaft/u-joints.

[1QWIKBIRD]

Have you checked to make sure the rear is square in the car? With all the work you've done, maybe the rear is not located properly under the car and is causing a bind in the driveline at speed? Measure from the center of the front wheels to the center of the rear wheels. Should be equal from side to side or very close. This is a long shot and there would have to be a pretty big difference to cause the problem, but ?????

Chris

[ThoR294]

Then tires/wheels are not the issue. Move on to axle runout/bearing play and driveshaft/u-joints.

new bearings, same vibration. 2 diff driveshaft, same vib. put 2 new u joints in my steel driveshaft that was balanced, same vibe....

[BonzoHansen]

axel runout?

[Mark42]

I'm out of ideas. But I sure am interested in knowing the cause and solution to this problem!

One last thought....

I once had a similar problem on a chevy monza. Balanced and re-balanced the tires, but a high speed vibration would not go away. Turns out that one of the tires was not round. I noticed it when the car was jacked up one day and I spun a wheel and I could see the out of round. Balanced, but out of round. Replaced the tire and the problem was solved.

Ok, now I'm out of ideas......

[BonzoHansen]

You'd likely see that on the balancer and that fact he rotated tires and no change eliminates tires.

[ThoR294]

and I replaced 2 tires and had them on the back. so that eliminated tires... next week im bringing it in to do inner and outer tie rods (they lock nuts are ceased, could not align it)... so im going to check the axles

[S.J.SLEEPER]

check for play tailshaft bushing to yoke @ rear of transmision.

when trans replaced, the trans wasn't hung from input shaft was it? possible slightly bent input shaft?not likely though.

also check to make sure locating pins in back of block are through the trans, if pushed into block can cause trans to be off-center(then the input shaft will be forced to ride @ a slight angle to engine,tearing up pilot bearing and possible clutch disc to pressure plate contact in nuetral

[BonzoHansen]

^^also good

... next week im bringing it in to do inner and outer tie rods (they lock nuts are ceased, could not align it)...
A little heat doesn't help that?

[ThoR294]

they were bad... I dont like heating up suspension parts :) haha. my uncle owns a garage so I get parts cheap. Im just going to get new ones.

my thought right now is something in the axles or possibly a tailshaft bushing... maybe they were bad in both transmissions

[DaSkinnyGuy]

sounds in the area of driveline angle / pinion angle / rear end centered. If its getting worse when the clutch is disengaging / or disengaged then your on the coast side of the gear.

you said your pinion angle is at -2, so thats good but if the rear end isnt centered, do you have an adjustable pan hard bar?

also what s.j. sleeper said about the yoke

[ThoR294]

I have an adj panhard bar and I centered the rear using that pendulum method as best as I could. that didnt change the vibration at all. Like i said the vibration is BAD when the clutch is DISENGAGED (Pedal in).

Im going nuts, I seriously like replaced everything... :( I hope its the tail shaft bushing or an axle thats kinda bad, I Just want to find the culprit!

[S.J.SLEEPER]

Like i said the vibration is BAD when the clutch is DISENGAGED (Pedal in).

like i said before.... check the locating pins on trans, possible input shaft/trans alignment or tailshaft bushing.

[Mike]

if you just want to eliminate a possibility, and feel like driving down to hamilton, you can throw my oem wheels on and see if it helps........

[Mark42]

You'd likely see that on the balancer and that fact he rotated tires and no change eliminates tires.

Unless you are actully looking for an out of round, I doubt you will notice 3/8" run out. And the guys balancing the tires probably wouldn't notice either. Its not obvious until something is held near the tire as it spins to see the gap change.

keep on looking, the problem will be found eventually.

[B4C]

Do you have access to a roadforce balancer?? Might want to try to road force balance your tires, it will tell you where to put each tire on the car to get the least amount of vibration. It measures tire/rim runout and will tell you if a tire has too much runout as well...might want to give that a shot mayybe help reduce the vibration.

[vipergtx500]

I have a similar problem at higher speeds, vibration is much worse when you put the clutch in because it doesn't have the engine to absorb the vibrations anymore. Wouldn't this problem be centered around the driveshaft/tailshaft bushing area because if it had to do with the wheels it wouldn't get worse with the clutch disengaged?

[BonzoHansen]

His problem is not tire balance. He replaced 2, no change. He rotated, no change. He's very likely got a drive line issue

Unless you are actully looking for an out of round, I doubt you will notice 3/8" run out. And the guys balancing the tires probably wouldn't notice either. Its not obvious until something is held near the tire as it spins to see the gap change.

keep on looking, the problem will be found eventually.

My 10 years in the business says otherwise, but maybe I did a better job than others. So maybe. But rotation would have highlighted that in an instant as the vibration would have changed.

[ThoR294]

i roadforced all tires, no issues. its driveline.

[B4C]

I know that einhander has the same problem with his car, 96 ws6 a4, and his mechanich said he has play in the output shaft of the trans, check the runout of your output shaft.

[ThoR294]

yeah. id be pissed if that trans i got off ebay a few years back has a bad output shaft as well as the one that came with my car....

[S.J.SLEEPER]

if its the tailshaft bushing, its very easily fixable. (remove d.s.,remove tail, punch bushing& seal out, install new ones, reassemble ) tailshaft bushings commonly forgotten about during rebuilds as they normally don't go bad before trans needs rebuild.

[BonzoHansen]

if its the tailshaft bushing, its very easily fixable. (remove d.s.,remove tail, punch bushing& seal out, install new ones, reassemble ) tailshaft bushings commonly forgotten about during rebuilds as they normally don't go bad before trans needs rebuild.

I'd buy into this in a heartbeat. I think my T56 needs one, it leaked past a new seal too easy. since you changed drive shaft 3 times that rules out the d/s and ujoints too, and you checked pinion angles. So trans play or rear issues. And this is a very likely and common occurrence.

[siguy]

did you get a chance to cheack the lower control arms for wear and movement. I would take it out to inspect each one then just stick a pty bar in there to see if it moves around (if they are after market see if you can get a stock set and drop them in to make sure)

The reason why I say this is I had a set of lakewood control arms that the ploy bushing wore out on the body side which produced unwanted movement and vibration plus a "clunk" noise.

[ThoR294]

No clunk noises during launch or anything. Ill inspect them though. Tuesday is judgement day :)

[ThoR294]

http://img532.imageshack.us/img532/8886/crossthing.jpg

That is cracked.... thats on the drivers side of the transmission crossmember, you can see the crack right above the bolt. I wonder if that is contributing to my vibration or not. the rest of that piece is stiff though.


I did not get a chance to check my output shaft and axles, no dial indicator :( hopefully friday

[Mark42]

I would think that a tail shaft vibration would only happen when the bearing is very worn. IE if there is only 5, 8, or 10 thousandths play in the drive shaft right at the tail shaft, with such a small diameter rotating mass, it would be hard to get a vibration strong enough to shake anything. Maybe if there is 30 thousandths run out, but then the tail shaft seal gets stretched out or chewed up and there is a leak.

What I am getting at is no leaking seal usually means the tail shaft bearing is not worn.

And if you can not feel any significan play, IE get a clunking sound by grabbing the yoke with both hands and forcing up/down or side/side then there is probably not enough wear to cause vibration.

Of course, I could be wrong. All complaints/posts to the contrary to the should be sent to President Obama, because he really cares.

[siguy]

gezz if you cant figure this out we might have to make a road trip to your house to get to the bottom of this because if this was my car i would have drove it off the clif by know lol lol its bothering me to see what the hell it could be

[ThoR294]

gezz if you cant figure this out we might have to make a road trip to your house to get to the bottom of this because if this was my car i would have drove it off the clif by know lol lol its bothering me to see what the hell it could be

do it. its bothering the **** out of me lol.


the tailshaft bushing is leaking a little on the trans... soooo thats bad? :O

I really hope its a tailshaft bushing or something. I WANT TO BE ABLE TO GO FAST :(

[siguy]

do it. its bothering the **** out of me lol.


the tailshaft bushing is leaking a little on the trans... soooo thats bad? :O

I really hope its a tailshaft bushing or something. I WANT TO BE ABLE TO GO FAST :(



have you put the is car in the air and run it to see if you can see anything strange (if not jack it up put it on jack stands and take you jack and push up on the center section of the axle and have a friend go through the gears) it will be not the same as if it was loaded with the wieght of the car but, maybe you can get a sense whats giving you the vibe.. and see if somthing is out of wack..)

[JL8Jeff]

Like i said the vibration is BAD when the clutch is DISENGAGED (Pedal in).

Well this should rule out the driveshaft, u-joints, rear, wheels, tires, brakes. If you have the vibration with the clutch pushed in then it's engine, trans, crossmember(I would be afraid of that cracked crossmember) or clutch. Since you have already swapped the trans around it could be something got forced. Try swapping the crossmember first since that might be the easiest solution. But if you need to pull the trans again then you might as well pull the clutch and flywheel to have them inspected properly.

[ThoR294]

the vibration is still there with the car in gear, etc. but it just gets amplified when i put the trans in neutral or i push the clutch pedal in.

[S.J.SLEEPER]

check transmission to block dowel pin alignment and how is the pilot bearing?

[WildBillyT]

http://csgbenefits.org/camarovibration.pdf

Have a ball. Yes, its for a '69 Camaro but it should still apply in most cases. My vote would be that it's somewhere in the clutch system. Pilot bushing, TO bearing, pressure plate, disc, flywheel.

[ThoR294]

so the flywheel out of balance could cause this? even though the motor is shut off and the trans is in neutral... the vibration is still present.

[siguy]

so the flywheel out of balance could cause this? even though the motor is shut off and the trans is in neutral... the vibration is still present.


Nope....... theres got to be something else

[JL8Jeff]

If there is a vibration with trans in neutral and engine shut off while coasting and still a vibration with engine running, car sitting still and clutch pushed in, then you have 2 different problems or your mount/crossmember is looking like the culprit. I find it hard to believe you have 2 different problems and can't identify/isolate 1 of them. Swap that cracked crossmember, that seems to be the common piece right now.

[ThoR294]

thats not the crossmember, its part of the body. It goes over the transmission, kinda like a tunnel brace or something. There is only 1 vibration. ITS ONLY at 70+MPH. It gets WORSE when I put the clutch in or put the transmission in neutral. anytime under 70 mph the car is smooth

[98redformula]

Based on the information posted, I would say you have a worn transmission bushing and driveshaft yoke which is allowing too much play at the front of the driveshaft. If this is your problem, you should see some wear on your driveshaft yoke, and be able to visibly see yoke movement if you push up on it at the U-Joint. I went through a very similar experience with a vibration that turned out to be a worn bushing. In order to fix this, I needed to replace the bushing and the driveshaft yoke, and then have the driveshaft balanced (after the yoke replacement). Note that you may not see the wear on your yoke as I believe you indicated you swapped your driveshaft during your troubleshooting. If you need more info, please feel free to PM me.

[ThoR294]

So, long story short, I have been chasing a god damn vibration for over 2 years in this god damn car. I have seriously replaced everything brand new except for the transmission.

I have the OE trans in it currently with 115k miles, and I have a wicked vibration over 70mph.

The vibration is noticeable with the car in gear and cruising... but as soon as I push the clutch pedal in... it gets way bad. same thing if i put it into neutral. As soon as i get below 70mph it vanishes.

I have had my wheels straightened, new tires. same vibration

took an alum driveshaft from a 01 camaro, new ujoints, vibration went down a little bit... but not much (i guess alum dampened the vibration)

had my OE steel shaft balanced with new u joints... same vibration

Found my Torque Arm was cracked, so I replaced it along with a relocation xmember... set the pinon angle to -2. same vibration.

Had my rear completely rebuilt (minus posi unit and axles)... same vibration. (axles are straight)




When I did the clutch, I decided to put the ebay transmission i got 3 years ago into the car. I dont remember when the vibration started either.

so I put the OE trans back in, same vibration.

I DONT KNOW WHAT IS WRONG. So what I want to do is check the ebay transmission and see what could possibly cause this. I am at wits end, please help

----

Just put that on LS1tech.

Im so ****ing pissed right now. I played with the yoke in the transmission and there is slight movement but not much... now would this be the bearing or the bushing? how could both transmissions have the same issue? did the ebay trans just get synchros thrown in it?

[BonzoHansen]

Don't assume on the axles & outer bearings, check for runout and bearing play. I have that problem in my Z right now. In fact I thought of your car today because of it. She's quiet at 70 and starts shaking above that, although not as bad as you describe.

[ThoR294]

new axle bearings, and the guy that rebuilt my rear said they were ok

[ThoR294]

question, think that detroit tru trac thing could cause my vibration?

[BonzoHansen]

I would not think so, but you never know. I still think you have to check axle flange runout. Do not assume.

[98redformula]

I believe your car has a t56 transmission, correct? If so, there is a bushing in the extension housing that keeps the clearance between the yoke and the extension housing tight to keep the yoke straight and concentric around the tranny output shaft. Now excess clearance between the yoke and bushing will allow vibration to occur. If you have a problem with the clearance that is causing the vibration, it can be due to either a worn bushing, a worn yoke, or both. So there are a few possibilities that would cause you to have the vibration after switching the transmission and/or drivershaft. Most likely, both the yoke and the bushing on your original equipment are worn. If so, then you would still experience a vibration by swapping the tranny and using your original driveshaft due to the worn yoke. If the ebay tranny didn't have the bushing replaced (which I wouldn't know), then the worn yoke would be compounded by a potentially worn bushing. Now to the swapping of the 01 aluminum driveshaft...If you swapped the 01 driveshaft into your original tranny, then you would likely still experience a vibration due to the worn bushing in your tranny, but it would likely be decreased because though the bushing is worn, the clearance between the "newer" yoke and the bushing would be tighter than that of your steel driveshaft's worn yoke. This is consistent with your post above indicating the vibration decreased when you swapped the driveshaft. Have you tried the 01 driveshaft with the ebay tranny? In theory, this would be the best combination to determine if this is your issue. I hope this helps.

[ThoR294]

Yes I did. I had the ebay trans in with 2 diff driveshaft... the last thing I did was swap back to the OE trans.

does anyone have a write up on doing the tailshaft bushing in the transmission in the car?

[siguy]

was this car ever in an accident ?

[ThoR294]

nope

[jwscab]

do you have a poly trans mount and rubber engine mounts? If so, change the poly mount to a rubber one.

t56 trans' are very sensitive to output shaft harmonics, and in some cases have problems with looseness in the 5-6 cluster extension(should be pressed on and off, sometimes they are not that tight and cause weird vibrations)

my brother had a weird resonance/vibration occurring in his car due to the mismatched engine mounts. once we put the rubber mount in the car, the vibrations went away.

[ThoR294]

I just ordered a rubber mount frm the zone... I have a poly trans mount and rubber engine mounts. Im going to try it... for $15 why not

[jts98z28]

sorry if this is a repost i didnt feel like reading all of this thread lol but did you try setting it at different pinion angles?

[ThoR294]

it was at like -6 before i set it to -2.. didnt change it at all

[Mark42]

Did you do the tail shaft bushing yet?

[ThoR294]

No sir. Apparently it has to be done with the transmission out of the car... Im going to throw in a rubber trans mount for kicks and giggles... if that doesnt do it then im just going to send the transmission to tick. IDK what I will do with the ebay transmisison, maybe try to fix it myself.

[WildBillyT]

No sir. Apparently it has to be done with the transmission out of the car... Im going to throw in a rubber trans mount for kicks and giggles... if that doesnt do it then im just going to send the transmission to tick. IDK what I will do with the ebay transmisison, maybe try to fix it myself.

Call Bob Hanlon!

[ThoR294]

details :O

[Tru2Chevy]

details :O

See Hanlon Motorsports in the sponsor list on the right ------->

- Justin

[ThoR294]

I put the rubber trans mount in... made no difference, now the vibration is even worse... it starts at ****ing 40mph. i want to kill myself. the weather is beautiful and my car is on ****ing jackstands in my driveway. if anyone wants to stop by and maybe look at it while I drive it on jack stands or something. HELP

[Tru2Chevy]

Tail shaft bushing still not replaced?

- Justin

[ThoR294]

I was told it has to be done out of the car... I just think its odd how 2 transmissions could have the same issue. I guess ill just drop the trans lol

[Tru2Chevy]

Is the tail of the T-56 removable like a 4L60e is? If so, just pull that off and leave the trans in place. Should be able to get it done that way.

- Justin

[ThoR294]

The tailshaft has to be removed outside of the car. you can take it off in the car but cannot put it back in. I am tempted to bring my ebay trans to hanlon and have them look at it. see if anything is bad... and if nothing is bad...... then.... i guess i need a rear lol

[Raist103]

anything ever come of this? the new, well "new to me" 98 z28 t56 has a vibration starting about 60-65 and gets bad about 70-80. it evens out some above that but is still bad. driving around up to those speeds has no vibration. 2 different sets of wheels no change. guess ill have to start checking some of these things. my car is not worst with the clutch in. anyone have a cheap drive shaft for sale?

[siguy]

anything ever come of this? the new, well "new to me" 98 z28 t56 has a vibration starting about 60-65 and gets bad about 70-80. it evens out some above that but is still bad. driving around up to those speeds has no vibration. 2 different sets of wheels no change. guess ill have to start checking some of these things. my car is not worst with the clutch in. anyone have a cheap drive shaft for sale?


I have a stock steel drive-shaft if you want to pick it up $40.00

Location Staten island, ny

[Raist103]

thx but after gas and tolls ill be over a 100 lol

[WildBillyT]

Might show up. If not in my bird then on my bike!

You ever get that vibration fixed?

[ThoR294]

Update. Swapped the rear. issue still there. I am going to look into the complete driveline angle (including trans, not just the rear). I set the rear pinion angle to -1 but didnt account for the trans...

Great info on LS1tech

http://ls1tech.com/forums/lt1-lt4-modifications/1635580-save-my-car-ls1tech.html

[ThoR294]

You ever get that vibration fixed?

NOPE. still there! swapped rears, transmissions, driveshafts, everything...

surprised you remembered :) I am thinking its the whole angle of my transmission and rear. I never measured my transmission angle.

Lots of great reads on my recent LS1 tech thread

http://ls1tech.com/forums/lt1-lt4-modifications/1635580-save-my-car-ls1tech.html

[WildBillyT]

NOPE. still there! swapped rears, transmissions, driveshafts, everything...

surprised you remembered :) I am thinking its the whole angle of my transmission and rear. I never measured my transmission angle.

Lots of great reads on my recent LS1 tech thread

http://ls1tech.com/forums/lt1-lt4-modifications/1635580-save-my-car-ls1tech.html

Very few from the Flemington area here, so yeah, I remember you!

Def. check the pinion angle w/ that adjustable TA.

[ThoR294]

I set the pinion angle at the rear to -1. but I didn't account for the trans. I think thats the culprit. Hopefully this friday I will get a chance to take it to my uncle's garage in Lebanon and set it on the alignment rack to check everything

[smoke_em94]

Let is know how u make out

[The_Bishop]

Did you set the pinion angle *in relation to the engine angle*?

When they say -1*, they don't mean -1* in relation to the ground. It's -1* in relation to the engine angle.

Say, if your engine is tilted back 4*, and you set your pinion angle at the same 4* back, you are at 0. If you set your pinion at 3* back, you are at -1*.

[ThoR294]

Did you set the pinion angle *in relation to the engine angle*?

When they say -1*, they don't mean -1* in relation to the ground. It's -1* in relation to the engine angle.

Say, if your engine is tilted back 4*, and you set your pinion angle at the same 4* back, you are at 0. If you set your pinion at 3* back, you are at -1*.

That is exactly what I DIDNT do in the first place. I just set the rear to -1* and I thought I was golden. Like an idiot, I didn't do digging. 3-4 years later, I now know what to do. Hopefully Friday I will be able to measure the engine angle and the rear, and do exactly like you said.

I'm so mad at myself right now. I am pretty convinced it is the driveline angle. Especially after reading through LS1 tech horror stories with vibrations and driveline angles fixing vibration issues.

Im so anxious for friday. I WANT THIS FIXED.

[Dudbird113]

I just used a pinion angle measurer thing (can be found in tool section of homedepot) and put it on my driveshaft. Only use that because u want alittle deflection in the drive shaft for the u joints.

[The_Bishop]

Thor, the reason I know about it is I was chasing down a drive line vibration, too.

[ThoR294]

Measured it as best as I could. Trans was pointing down 3* and rear was down 1*. so I shimmed the trans mount so it was pointing down 1* and rear pointing up 1* (as what my UMI angle finder said...)

It's still there, but its not as bad. I wonder if the angle finder just sucks and it's not getting an accurate reading... or my driveshaft may be too short since the car is lowered?

[3.4 grape of wrath]

I feel your frustration and anger. I had a vibration problem a couple years back and kept a diary of things that I checked and replaced. Similar to what you are going through. It ended up being the exhaust system. The combination of the rubber hangers hardening and the alignment was off from lowering the car. The noise would change when I shifted from drive to reverse. The way I discovered it was tapping the pipes with a rubber mallet from front to back with the suspension loaded and heard this loud vibration towards the rear.
I replaced all the rubber hangars and realigned everything and the vibration was gone.

[The_Bishop]

Wait, if you have an adjustable torque arm, you adjust *that* and forego the shims on the stock trans mount.

[ThoR294]

Wait, if you have an adjustable torque arm, you adjust *that* and forego the shims on the stock trans mount.

From what I read, everyone's transmission was pointing up... and mine was pointing down. So I didn't know if its because of the UMI relocation crossmember was making it point down. I can always remove the shims and go again.

I just fine tuned it by just winging the Torque Arm adjustment. It is not noticeable at ALL in gear/under throttle. but if you push the clutch in you can feel it. No where near as bad as before, though.

[WildBillyT]

http://www.stevesnovasite.com/forums/showthread.php?t=211270

Read up. The two guys in here are very tuned in to this type of thing. One's a senior guy at Chris Alston's.

[ThoR294]

I have the relocation crossmember for the Torque Arm... I wonder if the bushing placement for the T/A has anything to do with a vibration

[The_Bishop]

The transmission *should* point down. The engine/trans angles towards the rear.

[ThoR294]

I guess now that I think about it, that does make sense... The rear is lower so it should be down. duhh.

[sweetbmxrider]

The rear will rotate under acceleration thus aligning the driveline angles to 0* or so I have read on le internets.

[WildBillyT]

The rear will rotate under acceleration thus aligning the driveline angles to 0* or so I have read on le internets.

This is why traction bars exist

[The_Bishop]

Rotation is *much* lower on our torque arm cars. At stock(ish) power levels and with an aftermarket arm, I'd be surprised if it was more than .5*, and I'd be willing to bet it's closer to 0*.

[greenformula92]

I had a vibration too. turned out to be a combo of bad bushings in both the stock LCA's and the stock Panhard rod. just saying what my issue was. yours could be totally unrelated

[ThoR294]

I think it had it when i swapped the panhard out as well. I am going to put in poly/rod LCAs at some point. I was silly and bought them a long time ago

[ThoR294]

Finally figured it out. I bought this angle finder:

http://www.amazon.com/gp/product/B006JR8XBG/ref=oh_details_o04_s00_i00?ie=UTF8&psc=1

I re-installed my poly transmission mount. Transmission was pointing down 3 degrees. I set the rear to point UP 2.65-2.75 degrees. Vibration is now GONE. I have a slight vibration at 90mph.... but that is probably from everything being solid, and it is NO WHERE NEAR as bad as it used to be. THANK GOD I can't believe it took me this long to do this research and figure out how to properly set the angle. I was just setting the rear before *sigh*

[sweetbmxrider]

This is how you learn.

[ThoR294]

This is how you learn.

Indeed. Lesson learnt :P

[ThoR294]

so Im bringing this back up. It is still there, and I have moved the angle everywhere I am pretty sure. Still stumped on how to squash this. I am wondering if its the relocation X member that is giving me the wicked vibe

[B4C]

I didn't read the whole thread but I see you have an adjustable phb listed in your sig. Have you ever had it on an alignment rack to check if your rear axle is centered?

[ThoR294]

I did the whole pendulum thing to center the rear when I first installed that bar.

On LS1TECH, I was told to try and measure the transmission angle from the shifter plate. i may be getting a bad reading from the transmission under the output shaft. Also, was told to have -2 total angle... so if the trans is -3 the rear should be -1 and that should work for me. so I am going to try to pull the console out on my uncles alignment rack and do it AGAIN... and pray to the vibration gods

[B4C]

Pendulum thing?

[WildBillyT]

Pendulum thing?

Probably a plumb bob off of the quarter panel to the axle flange. That's what I've done in the past.

[LTb1ow]

Assuming you are correct at pinion angle here, I fail to see what changing the drive line angle will change for the better. Unless you have a very ****** front U joint pinion angle, what does the trans care what angle its at? (within reason)

Are you sure you are setting pinion angle correct and have good U joints?

[WildBillyT]

I did the whole pendulum thing to center the rear when I first installed that bar.

On LS1TECH, I was told to try and measure the transmission angle from the shifter plate. i may be getting a bad reading from the transmission under the output shaft. Also, was told to have -2 total angle... so if the trans is -3 the rear should be -1 and that should work for me. so I am going to try to pull the console out on my uncles alignment rack and do it AGAIN... and pray to the vibration gods

If you have -3 off of the trans and -1 off of the rear you have -4.

[LTb1ow]

If you have -3 off of the trans and -1 off of the rear you have -4.

Pinion angle does not care about trans angle (to an extent)
http://ls1tech.com/forums/gears-axles/1103876-measuring-pinion-angle.html

I am confused why you changed or messed with driveline angle at all.

[ThoR294]

so eff my trans angle and just measure at the rear?

Im messing with everything because I can't kill this vibration no matter what I set my rear at...

http://ls1tech.com/forums/suspension-brakes/1726270-do-you-have-torque-arm-relocation-x-member-vibration.html

http://ls1tech.com/forums/lt1-lt4-modifications/1725298-still-trying-kill-my-vibration.html

http://ls1tech.com/forums/suspension-brakes/1638247-chasing-down-vibrations-freeway-speeds-umi-strano-parts-2.html

[Featherburner]

Pinion angle does not care about trans angle (to an extent)
http://ls1tech.com/forums/gears-axles/1103876-measuring-pinion-angle.html

I am confused why you changed or messed with driveline angle at all.

Why?

[WildBillyT]

so eff my trans angle and just measure at the rear?

Im messing with everything because I can't kill this vibration no matter what I set my rear at

There's conflicting info on the "best way" to do it.

Mike @ Chris Alston's told me something like this:

any engineering principle or drive line theory or power transmission theorist will tell you 2 u-joints must be in phase for minimal loss or vibration. both u-joints must be acounted for .

what I find many people get confused about is the difference between pinion angle & u-joint angle.

pinion angle is the difference between the angle of the engine (power output) & the angle of the pinion ( power input), in degrees.

u-joint angle is the angle from the transmitting shaft across the joint to the input or output.

example:
jacked up 4x4 truck.. engine level to ground 3 feet higher than pinion which is also level to ground.
pinion angle = 0 degrees
u-joint angle = 35 degrees

same 4 x 4, but engine is down in back 5 degrees to ground, pinion is up 3 degrees from ground.
pinion angle= 2 deg. down
u-joint angles =20 front 24 rear

hope this helps.. my fingers are tired from typing...

[LTb1ow]

Why?

Perhaps I am mixing up terms, but I am referring the only point of adjustment on a 4th gen torque arm suspension setup, which is at the rear end via torque arm. I have rarely read of F-bod three link guys adjusting transmission angles at mount, but, to be fair, I am a close minded LT1 person who goes straight with racing.

I do not see why a trans angle would have changed or need to be changed enough to affect what the torque arm adjustment couldn't bring into spec. Its a low power car, so no need for crazy angles, just make it factory stock and be content. Since he has done that (assuming correctly) already with a stock torque arm etc, I just don't see what adding in another variable is gonna help.

But, this is a lot of assuming.

[WildBillyT]

Perhaps I am mixing up terms, but I am referring the only point of adjustment on a 4th gen torque arm suspension setup, which is at the rear end via torque arm. I have rarely read of F-bod three link guys adjusting transmission angles at mount, but, to be fair, I am a close minded LT1 person who goes straight with racing.

I do not see why a trans angle would have changed or need to be changed enough to affect what the torque arm adjustment couldn't bring into spec. Its a low power car, so no need for crazy angles, just make it factory stock and be content. Since he has done that (assuming correctly) already with a stock torque arm etc, I just don't see what adding in another variable is gonna help.

But, this is a lot of assuming.

He's been kicking this around for a while now so any discussion is good IMO.

If the motor mounts are aged (or aftermarket) and the trans mount is aged (or aftermarket) the angle of the crank/trans output shaft could be different than stock and would require a different setting out back if it's far enough out. I'm not saying that the torque arm couldn't be adjusted to correct the issue, just that you might not be able to say "set the rear at -2" or whatever and assume you are good.

[ThoR294]

New trans mount... Motor mounts LOOK OK and seem OK lol.

[ThoR294]

bumping this up.

Currently, the vibration is still present. It is no where near as bad as it used to be, but it is still there. I can move the angle and the vibration gets worse in any direction, but I can't get it to go away. I am beginning to think it is just because I have the torque arm relocation Xmember, or I just can't find the right angle.

Does ANYONE have the same T/A setup as I do, and not have this problem?

[greenformula92]

Well I had a adjustable tq arm on a 3rd gen. Xmember relocation and a t56. I had no vibration what so ever.

[ThoR294]

Well I had a adjustable tq arm on a 3rd gen. Xmember relocation and a t56. I had no vibration what so ever.

I wonder if I'm just setting my angle like an idiot

[LTb1ow]

We also do not know your definition of driveline vibration.

[ThoR294]

We also do not know your definition of driveline vibration.

Cruising at 75 maintain speed you feel nothing.

Take foot off gas you feel a little rumble in the car

Push clutch pedal in and it feels like driveshaft is out of balance and going to fly out of the car

[LTb1ow]

Just reread thread, so you have OEM rubber motor mounts and a poly trans mount...?

[ThoR294]

Yup. I've put rubber trans mount in and that changed nothing. Only thing that changes this is adjusting the torque arm.

In the process of putting prothsne motor mounts. Just need a day at my uncles garage to do it lol