VSS Problem - NJFBOA - Home of New Jersey's Camaros and Firebirds

91DropTop · 02-24-2008, 11:27 AM

OK My speedo doesnt work i pulled vss out and ran it with a drill and it reads fine but when in the trans nothing, i checked the gear on the tailshaft doesnt seem to be spinning so thats ok and none of the gears look chewed up, the only thing i can think of is the 2 gears arent mating for some reason, i know there is 2 vss options for my car and im wondering if one has a longer shaft and i got the wrong one. Has anyone else had this issue

it would probably help if i told you i had a 91 rs with a 700r4

Tru2Chevy · 02-24-2008, 04:00 PM

Did you change anything just before the speedo went out, or did it just happen out of the blue one day?

- Justin

91DropTop · 02-24-2008, 06:05 PM

Quote:

Originally Posted by Tru2Chevy

Did you change anything just before the speedo went out, or did it just happen out of the blue one day?

- Justin

speedo hasnt worked since i got the car, neither did most of the guages and the tach thats why i did the dash upgrade, now everything works beautiful except the speedo. i finally have the issue narrowed down to something in the tailshaft for some reason i think the vss gear and the gear in the tailshaft arent making contact cause if i spin the the vss with a drill i get a reading on the dash. i know there are 2 sensor options for my car i just dont know what the difference is.

Tru2Chevy · 02-24-2008, 08:12 PM

I think there were different VSS units based on which gear you need installed in it. Not positive though.

- Justin

91DropTop · 02-24-2008, 08:22 PM

im gonna take a better look once i get access to a lift again im spoiled no more working on the floor for me

Fast92RS · 02-25-2008, 11:39 AM

there are only two different speed sensors one for 34-39 tooth driven gear (black sensor) and one for a 40 - 45 tooth driven gear (white sensor). Check to see if the gear is sitting at the correct spot on the shaft. I would try and put the rear on jack stands and put the car in gear and see if you get a reading at the sensor while the car is in gear. It may be the gear is sitting to far back and just need to adjust it out or buy a new gear.

91DropTop · 02-25-2008, 04:34 PM

Quote:

Originally Posted by Fast92RS

there are only two different speed sensors one for 34-39 tooth driven gear (black sensor) and one for a 40 - 45 tooth driven gear (white sensor). Check to see if the gear is sitting at the correct spot on the shaft. I would try and put the rear on jack stands and put the car in gear and see if you get a reading at the sensor while the car is in gear. It may be the gear is sitting to far back and just need to adjust it out or buy a new gear.

the gear slides super easy back and forth on the shaft. is it supposed to be tight maybe i have the wrong sensor or a worn gear. i think i have the white one installed now but how do i find out the one that is supposed to be in there?

Tru2Chevy · 02-25-2008, 05:10 PM

Figure out which sensor you have for sure, and then count the number of teeth on the gear that is attached to it. Then post back with your findings.

- Justin

91DropTop · 02-25-2008, 05:17 PM

Quote:

Originally Posted by Tru2Chevy

Figure out which sensor you have for sure, and then count the number of teeth on the gear that is attached to it. Then post back with your findings.

- Justin

ok so it doesnt matter what sensor you have as long as the gear is the correct tooth count for the sensor??

Tru2Chevy · 02-25-2008, 06:39 PM

Quote:

Originally Posted by 91DropTop

ok so it doesnt matter what sensor you have as long as the gear is the correct tooth count for the sensor??

Yea, like Fast92RS said, the 34-39 tooth gears are only for the black sensor and the 40-45 tooth gears are only for the white sensor. If you have a (for example) a 38 tooth gear and a white sensor, then things are most likely not lining up right

- Justin

91DropTop · 02-25-2008, 07:36 PM

makes sence i have a feeling i have the wrong sensor i had a 50-50 chance and im wrong 100% of the time lol

Fast92RS · 02-25-2008, 08:17 PM

Quote:

Originally Posted by 91DropTop

the gear slides super easy back and forth on the shaft. is it supposed to be tight maybe i have the wrong sensor or a worn gear. i think i have the white one installed now but how do i find out the one that is supposed to be in there?

The gear should be snug on the sensor. The gear could be worn. And like tru2chevy said check to make sure you have the right sensor.

91DropTop · 02-25-2008, 08:29 PM

Quote:

Originally Posted by Fast92RS

The gear should be snug on the sensor. The gear could be worn. And like tru2chevy said check to make sure you have the right sensor.

ok looks like i have some homework to do, but i do know the gear slips on the shaft with no resistance but maybe the correct vss has a sightly bigger shaft either way at least i have some great info to go with, ill see what i can do this weekend and let you guys know. Thanks a Ton!!

91DropTop · 03-01-2008, 04:43 PM

Ok got a VSS from the dealer and slapped it in and everything works fine now...it turns out i just had the wrong sensor...the dealer only showed one option for my year as opposed to 3 options at napa. So the speedo works now and all i have to do is calibrate it

i also need a new tail shaft housing for the 700r4 cause mine is cracked and leaking by sensor, i guess when i had tranny rebuilt they used a BFH to get it apart and cracked it