Today's Posts Mark Forums Read Calendar
Go Back   NJFBOA - Home of New Jersey's Camaros and Firebirds > Tech Forums > Brake, Chassis and Suspension Tech

Notices


Reply
 
Thread Tools
Old 10-27-2010, 06:51 PM   #1
SeanC
 
Join Date: Apr 2009
Posts: 192
iTrader: (0)
Lower Control Arm Problem

Hey guys,

I installed UMI adjustable lower control arms (poly/rod end) a while back, and the wheels never looked properly centered in the wheel well. I made sure I matched the length of the control arms to the stock ones (laid them on top of eachother and put bolts through both holes). The wheels are sitting towards the back of the car to the point of barely being able to put my hand between the tire and edge of the rear bumper.

I tried to adjust them today, and I pushed the rear towards the front of the car to center it (used a tape measure to center it the best I could). Because I moved the rear forward, I had to shorten the length of the control arms. Finished both sides, lowered the car, and they are almost exactly the same position as before!!! How is this possible? I really dont get what the problem is...I just can't make sense out of it. I told someone at UMI about the problem and they looked at me like I had 4 eyes...

Any ideas?
SeanC is offline   Reply With Quote
Old 10-27-2010, 07:17 PM   #2
//<86TA>\\
Power Member
 
//<86TA>\\'s Avatar
 
Join Date: Oct 2007
Location: Milford NJ
Posts: 1,526
iTrader: (1)
Quote:
Originally Posted by SeanC View Post
Hey guys,

I installed UMI adjustable lower control arms (poly/rod end) a while back, and the wheels never looked properly centered in the wheel well. I made sure I matched the length of the control arms to the stock ones (laid them on top of eachother and put bolts through both holes). The wheels are sitting towards the back of the car to the point of barely being able to put my hand between the tire and edge of the rear bumper.

I tried to adjust them today, and I pushed the rear towards the front of the car to center it (used a tape measure to center it the best I could). Because I moved the rear forward, I had to shorten the length of the control arms. Finished both sides, lowered the car, and they are almost exactly the same position as before!!! How is this possible? I really dont get what the problem is...I just can't make sense out of it. I told someone at UMI about the problem and they looked at me like I had 4 eyes...

Any ideas?
when you moved the axle to the centered position, was the suspension loaded, or was the rear hanging? the axle moves in an arch, so when you drop the rear it will move.
//<86TA>\\ is offline   Reply With Quote
Old 10-27-2010, 07:28 PM   #3
deadtrend1
11 second club / Moderator
 
deadtrend1's Avatar
 
Join Date: Aug 2004
Location: West Berlin, NJ
Posts: 7,148
iTrader: (11)
Just make them the same length as the stock ones were. There really is no need for adjustable LCA's unless you are running really really ridiculously big drag tires.

Adjustable PHB if car is lowered. But that would be about it.
__________________
2001 Trans Am WS6 •SLP Loudmouth II •UMI Suspension •12.857 @ 109.57

1996 Trans Am WS6 •Pacesetter Longtubes •Strange 12 Bolt •Spohn Suspension •11.152 @ 123.85
deadtrend1 is offline   Reply With Quote
Old 10-27-2010, 07:34 PM   #4
SeanC
 
Join Date: Apr 2009
Posts: 192
iTrader: (0)
I had a jack under the rear to put a little compression on it, but it definitly wasnt under the full weight of the car...If i jacked it up too far I couldn't move it anyways....

How are you suppose to have it? What I dont get is why my tires are still back too far towards the rear of the car....I have the rod end turned in much further than before (shortening the LCA). Even if I had the suspension completely unloaded, wouldnt this still pull the rear forward?

And the problem is that IF I keep them at the stock LCA length, for some reason the rear just looks off. I'm not being picky, but I know for a fact that it isnt right. You can tell that there is a big difference...I've asked numerous people to tell me what looked wrong with the rear wheels and they said they were not centered in the wheel well...

Last edited by SeanC; 10-27-2010 at 07:39 PM.
SeanC is offline   Reply With Quote
Old 10-27-2010, 07:55 PM   #5
deadtrend1
11 second club / Moderator
 
deadtrend1's Avatar
 
Join Date: Aug 2004
Location: West Berlin, NJ
Posts: 7,148
iTrader: (11)
are you running relo brackets?
__________________
2001 Trans Am WS6 •SLP Loudmouth II •UMI Suspension •12.857 @ 109.57

1996 Trans Am WS6 •Pacesetter Longtubes •Strange 12 Bolt •Spohn Suspension •11.152 @ 123.85
deadtrend1 is offline   Reply With Quote
Old 10-27-2010, 07:57 PM   #6
SeanC
 
Join Date: Apr 2009
Posts: 192
iTrader: (0)
Yes, I have relocation brackets (bottom hole). The car is stock height too..
SeanC is offline   Reply With Quote
Old 10-27-2010, 08:00 PM   #7
deadtrend1
11 second club / Moderator
 
deadtrend1's Avatar
 
Join Date: Aug 2004
Location: West Berlin, NJ
Posts: 7,148
iTrader: (11)
Bolt in I assune, go to the middle hole
__________________
2001 Trans Am WS6 •SLP Loudmouth II •UMI Suspension •12.857 @ 109.57

1996 Trans Am WS6 •Pacesetter Longtubes •Strange 12 Bolt •Spohn Suspension •11.152 @ 123.85

Last edited by deadtrend1; 10-27-2010 at 08:02 PM.
deadtrend1 is offline   Reply With Quote
Old 10-27-2010, 08:04 PM   #8
SeanC
 
Join Date: Apr 2009
Posts: 192
iTrader: (0)
Yeah they are bolt in....What would going to the middle hole do (not to question your advice)?

I really want to keep it in the bottom hole to have them be most effective....I dont see any reason why the bottom hole wouldnt work..
SeanC is offline   Reply With Quote
Old 10-27-2010, 08:10 PM   #9
deadtrend1
11 second club / Moderator
 
deadtrend1's Avatar
 
Join Date: Aug 2004
Location: West Berlin, NJ
Posts: 7,148
iTrader: (11)
Stock suspension worked for years as is. Relo brackets aren't really necessary, unless you are lowered extremely and in that case it MIGHT be a good idea to use the bottom one.
__________________
2001 Trans Am WS6 •SLP Loudmouth II •UMI Suspension •12.857 @ 109.57

1996 Trans Am WS6 •Pacesetter Longtubes •Strange 12 Bolt •Spohn Suspension •11.152 @ 123.85

Last edited by deadtrend1; 10-27-2010 at 08:11 PM.
deadtrend1 is offline   Reply With Quote
Old 10-27-2010, 08:13 PM   #10
SeanC
 
Join Date: Apr 2009
Posts: 192
iTrader: (0)
okay....how is moving to the middle hole going to fix the problem though??? I'm not understanding why when I adjust the length of the LCAs why the rear isnt moving accordingly...
SeanC is offline   Reply With Quote
Old 10-28-2010, 07:20 AM   #11
sweetbmxrider
Meet Coordinator
 
sweetbmxrider's Avatar
 
Join Date: Jan 2008
Location: brick/pt. pleasant beach
Posts: 19,341
iTrader: (12)
make sure you aren't bottoming out the drive shaft or binding the torque arm
__________________
sweetbmxrider is offline   Reply With Quote
Old 10-28-2010, 09:05 AM   #12
KirkEvil
10 Second Club
 
KirkEvil's Avatar
 
Join Date: Feb 2008
Location: Eatontown
Posts: 1,647
iTrader: (11)
Quote:
Originally Posted by sweetbmxrider View Post
make sure you aren't bottoming out the drive shaft or binding the torque arm
^I would def check out this, especially the DS.

Moving to different holes on relo brackets will not change anything...The lower mounting holes are actually moved forward to account for the swing radius of the LCA's.

You have to realize that when you took off your stock LCA's to line them up with the new, they were not loaded. The stock rubber mounts will compress MUCH more than a poly/rod end mount. That is why you originally had the tires pushed back. I cant explain why you cant adjust, haha.

fyi, I have 1.75" clearance between the tire and rear/front body panels to center a 26" tall tire.
__________________
1999 C5 FRC: 12.7@114
2008 TBSS: 12.48@108
2017 Silverado 2500 do you even lift breh?

Last edited by KirkEvil; 10-28-2010 at 09:12 AM.
KirkEvil is offline   Reply With Quote
Old 10-28-2010, 10:01 AM   #13
SeanC
 
Join Date: Apr 2009
Posts: 192
iTrader: (0)
This is a dumb question, but how can I tell if the DS is bottoming out? Will it be obvious by looking at it?

Now i'm all worried that I'm damaging something and i'm suppose to take my car to the track for the first time Saturday
SeanC is offline   Reply With Quote
Old 10-28-2010, 10:09 AM   #14
KirkEvil
10 Second Club
 
KirkEvil's Avatar
 
Join Date: Feb 2008
Location: Eatontown
Posts: 1,647
iTrader: (11)
Just look at it, check the TA rubber mount too. Theres really no reason for it to be bottomed out since your tires are actually too far back.

Do you have a stock rear?
__________________
1999 C5 FRC: 12.7@114
2008 TBSS: 12.48@108
2017 Silverado 2500 do you even lift breh?
KirkEvil is offline   Reply With Quote
Old 10-28-2010, 10:19 AM   #15
SeanC
 
Join Date: Apr 2009
Posts: 192
iTrader: (0)
Yup stock rear....ill take pictures later today so you guys can see the position of the wheel in the wheel well. I'm really at a loss...lol. just doesnt make sense

Last edited by SeanC; 10-28-2010 at 10:20 AM.
SeanC is offline   Reply With Quote
Old 10-28-2010, 10:24 AM   #16
KirkEvil
10 Second Club
 
KirkEvil's Avatar
 
Join Date: Feb 2008
Location: Eatontown
Posts: 1,647
iTrader: (11)
How much did you pull in the rod end since aligning them with the stockers? and how much adjustment do you have left?
__________________
1999 C5 FRC: 12.7@114
2008 TBSS: 12.48@108
2017 Silverado 2500 do you even lift breh?
KirkEvil is offline   Reply With Quote
Old 10-28-2010, 10:31 AM   #17
SeanC
 
Join Date: Apr 2009
Posts: 192
iTrader: (0)
I'm honestly not sure how much shorter I have them now than the stock ones (adjusted them a few different times). Right now I have about 4 threads on the rod end exposed....I honestly can't shorten either one anymore (for some reason the threads are screwed up. I had trouble getting them that short to begin with...I just couldn't believe I made them that short and the wheels still seem to be too far back?
SeanC is offline   Reply With Quote
Old 10-28-2010, 10:34 AM   #18
KirkEvil
10 Second Club
 
KirkEvil's Avatar
 
Join Date: Feb 2008
Location: Eatontown
Posts: 1,647
iTrader: (11)
Have you looked under the car to make sure the TA hasnt popped out of the rubber bushing off the trans?
__________________
1999 C5 FRC: 12.7@114
2008 TBSS: 12.48@108
2017 Silverado 2500 do you even lift breh?
KirkEvil is offline   Reply With Quote
Old 10-28-2010, 10:35 AM   #19
sweetbmxrider
Meet Coordinator
 
sweetbmxrider's Avatar
 
Join Date: Jan 2008
Location: brick/pt. pleasant beach
Posts: 19,341
iTrader: (12)
i'm interested in a pic but you could have a bent mount somewhere possibly causing a bind. you could try going real drastic and shortening the lcas by say 2 inches just to see if the rear pulls forward.
__________________
sweetbmxrider is offline   Reply With Quote
Old 10-28-2010, 10:49 AM   #20
SeanC
 
Join Date: Apr 2009
Posts: 192
iTrader: (0)
I'd be extremely surprised if the TA is out of the rubber mount, but i'll definitly check it out when I get home from work. And as far as shortening the LCAs by a lot to see if it pulls forward...wells that what I thought I did yesterday lol

yesterday I did each side one at a time...took one off, pushed rear end forward until the measurements from each body panel were equal, set the lower control arm length to match the hole, and bolted it up...I can't say for sure that it didn't move at all, but it still is back towards the rear.

I want it to move forward, but i'm also worried my tires are going to rub on the inner fender in the front (18" c5 rims)
SeanC is offline   Reply With Quote
Old 10-28-2010, 11:07 AM   #21
sweetbmxrider
Meet Coordinator
 
sweetbmxrider's Avatar
 
Join Date: Jan 2008
Location: brick/pt. pleasant beach
Posts: 19,341
iTrader: (12)
moving the rear forward won't affect the front suspension in that way.

you should make reference points on the frame that are equal on both sides and measure that way. use 3 points of reference too. body panels can be off.
__________________
sweetbmxrider is offline   Reply With Quote
Old 10-28-2010, 11:59 AM   #22
SeanC
 
Join Date: Apr 2009
Posts: 192
iTrader: (0)
Okay, ill try that. I was worrying about my rear tires rubbing (not the fronts). Sorry I didnt word my last post very well...I should have wrote "rub on the inner front part of the rear fender"

Last edited by SeanC; 10-28-2010 at 12:08 PM.
SeanC is offline   Reply With Quote
Old 10-28-2010, 12:33 PM   #23
sweetbmxrider
Meet Coordinator
 
sweetbmxrider's Avatar
 
Join Date: Jan 2008
Location: brick/pt. pleasant beach
Posts: 19,341
iTrader: (12)
ah ok, i took a hammer to my inner fenders in a few spots when i had the 18 x 10.5's on
__________________
sweetbmxrider is offline   Reply With Quote
Old 10-28-2010, 04:31 PM   #24
SeanC
 
Join Date: Apr 2009
Posts: 192
iTrader: (0)
Here are the pictures (sorry they're not very good...from my cell phone). It seems like they look better than they did, but they still do not look centered...you can see the front inside part of the wheel wells so well...



SeanC is offline   Reply With Quote
Old 10-28-2010, 04:50 PM   #25
V
Stalker
 
V's Avatar
 
Join Date: Aug 2004
Posts: 12,077
iTrader: (12)
im tired after a long work day but if you think about it... all you'll really doing by shortening the rear lca is adjusting angles, not really pulling the rear closer. the 10 bolt main housing is a set distance from the tailshaft of the trans. the TA is bolted to the rear and attached at the trans... you'd, in theory, need to shorten that there to bring the wheels forward.. by shortening the LCAs, you are just really rotating the rear axle housing and changing the pinion angle.

now i know with my adjustable TA, i could adjust the front rod end and make many more adjustments

Last edited by V; 10-28-2010 at 04:52 PM.
V is offline   Reply With Quote
Reply

  NJFBOA - Home of New Jersey's Camaros and Firebirds > Tech Forums > Brake, Chassis and Suspension Tech


Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

» Sponsor List














All times are GMT -5. The time now is 05:52 AM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.