I know that changing the rear end also requires recalibration of the speedometer to get the correct reading. How would I go about recalibrating the speedometer to ensure I get the correct reading?

PS, I plan to go from a 2.73 to a 3.23 if that helps.

Thanks.

 

Need to change one or both speedometer drive/driven gears in the transmission. Using the correct ones will calibrate both the ECM and the speedometer.

RBob.

 

Where can I learn which ones I need and where can I get the gears? Thanks.

 

Anyone? Please?

 

Looking for the answer as well posting to get a notice.

 

I have tried searches myself since I've done the same 2.73 to 3.23 swag in my 91. The few calculators I've come across lead me to think the Grey 15 tooth drive gear and the Blue 38 tooth driven gear are correct for proper function, but in my post nobody repled in agree or disagree, so I'm not sure. I called a dealer yesterday and they weren't helpful. Post what ever info you find as I will keep you up to date with my project as well.

Jim

 

I tried the same things before (minus the dealer). I will look through and try to find a calculator. I may try the dealership tomorrow, too.

 

I remember finding this before some where "for a 3.23 I will need 17 tooth drive gear and 42 tooth driven gear". That is what I found on some calculator, not that I remember where I found the calculator, that may help. Your info comes out to 2.5333333333333333333333333333333. Mine is 2.4705882352941176470588235294118. (Large number divided by small) I had thought that the end numbers were the same if you divided the two numbers, but I was wrong.

 

I was reading some post here on the site, and the issue came up about the gearing option you just mentioned, but was shot down because (this is what I heard) that the number of teeth for both gears combined should be about mid 50's. I also heard that a driven gear with more than 40 teeth will require the use of a differnt tail section which I really don't want to replace. I know that the stock drive gears where 15 and 17 tooth. I really wish I new, but I think I'm just going to go with what I've found and see if it works. Keep use posted if find out anything.

Jim

 

700R4.com has a calulator to find the gears you need. Just say tires and the rearend gears then it will say what two gears you need for the speedo.

 

Here is the gears for a tires 235/55R16 with 3.23 rear: Drive gear 17 tooth Driven Gear 42 tooth. This is the direct link for the calculator.

 

Did that help anyone? I am going to the dealership Tuesday ( I think) and see how much they are.

 

They might not have all the gears anymore. I went and asked for 2 gears and said they couldn't get it, but they could have been bull ****ting me.

A guy there was saying to get a thing from Jet that will calibrate the VSS just by telling the size of tires and the gears.

I just checked and Jet says it's only for 4L60E 94-02.

 

Well, that doesn't sound hopefull. My aunt is related to the owner of the largest Chevy dealership in town, so I might be able to pull some string if they are BSing me/you.

 

Drive Gears

http://www.bowtieoverdrives.com/cata...AT&CATID=DA2A1

Driven Gears

http://www.bowtieoverdrives.com/cata...AT&CATID=DA2A2

I might just go through that site

 

Yeah, that would probably be easier. And not too expensive. I am going to go crawling around and try to find where they go on the car...

 

In the tailhousing at the rear of the transmission, the driven gear goes in the VSS and the drive gear goes on a shaft.

 

Ok. Thanks. That makes finding it easier. No looking for it. I am glad that they have them for sale instead of having to go to the dealership to get them.