I have a couple of questions that I couldn't really find the answer to browsing through old posts. What exactly is the relation between the RPO code on a car (d8n, d8i, etc...) and the correct VSS sensor part number? People don't distinguish between different VSS sensors when they do TPI retrofits, but if you go to the dealer to pickup a VSS, you need the RPO code.

My guess is that its related to the rear end gearing. Sounds reasonable, but I would like to know for sure. Was there a different VSS used on older 700R4s compared to newer ones? What about late model 700R4s compared to 4L60E trannys?

 

When you go from 2:73s to 4:11s you move the ring gear closer to the pinnion gear to maintain proper clearance between the gears. Same thing with the speedo gears. You have to move the driven gear closer to the drive gear. Also the earlier cars still used the cable upto the gauge cluster. Ithink in 89 the general moved the electronics to the trans and ran wires to the dash.

 

Not entirely.

You need to know that when you go to the dealer they will list 3 or more VSS numbers for a 1989 GTA. But, that's because there are two for the 700-R4. One takes a certain tooth count gear range, (like 41-45) and the other takes the other gear tooth count. Then there is the T5. That's three, minimum. If he shows you an RPO that has to do with an automatic and you have a T5 car, then don't waste your time with that one.

It sucks to have to do the job for some of the counter personnel, but it doesn't take all that much to find the right VSS.


All the gear driven VSSs in thirdgens were a 4 pulse signal. One from an 86 TA should work in a 92 RS. Then just make sure the tooth count / VSS match up.

 

Ok, so there are two different vss versions for the 700R4, and one for the T5. All of them are a 4 pulse signal. And the difference between the two 700R4 versions are the speedo gears that you can use with it? Did I catch that correctly? When you purchase the VSS, does it already come with a set of speedo gears on it? Or do you figure out which you need and purchase them separately?

Thanks for all your help so far. Everything I had come across before all sounded the same "Go get your RPO code,.....yada yada yada..."

 

Nope, you have to buy them separately.

 

The 2 pulse VSS models were those with cable speedo, and that VSS is built into the speedo.

The trans. mounted VSS were always 4 pulse in thirdgens.

They will oftentimes list more than one version for the T5. There actually are two different gear lengths (for cable drive) so I think there are indeed 2 different T5 VSSs, although most of what I deal with is mechanical cable.

You need the gears also.

 

Now I'm curious. Can you install a tranny mounted vss on an older 700R4 which used the cable running up to vss on the speedo?

By the way, I've noticed quite a large difference in VSS pricing between different part numbers. I found that surprising.

 

Yes. It just bolts right in..

 

Ah this is what I've been looking for. So a VSS out of an 86-89 V6 firebird 700r4 will work in an older (85) 700r4 mated to a 305.

Are there differences between a VSS for a 3.42 rear end and a 3.45 rear end?

 

"So a VSS out of an 86-89 V6 firebird 700r4 will work in an older (85) 700r4 mated to a 305."


Do you have the electrical harness/ 2 wire connector for the VSS already in your car?

EDIT: quoted the wrong post

 

Which car?