Hey guys, I swapped the rear end in my 1991 Trans Am (2.73 to 3.45 gears) and I'm looking to order the proper speedometer gears. Stock, the car should (although I'm not certain, please correct me if anything) have 37 driven/17 tooth drive gears (both red). I need a 41 tooth driven and 15 tooth drive gear for my speedo to work correctly. However, online I'm seeing "34-39 tooth" and "40-45 tooth" speed sensors for sale. Does that mean I'll need to buy a new VSS as well?

 

most of the gears are nla even in aftermarket, get a Dakota digital sgi-5

 

Oh really? I found a website that offers speedo gears. Anymore info about about the device you're talking about?

 

http://www.dakotadigital.com/index.c...roduct_id=126/

 

Seems a bit pricey and unnecessary for me. Thank you though.

 

http://www.transmissioncenter.net/sp...0gear%20driven

I bought mine from this site but I have an 86 700R4, yours is different I think..

 

Yeah I believe you have the mechanical speedometer and the gear for that won't work for mine. I actually called that company you posted up and they don't have the 41 tooth gear I'm looking for to work with my electric VSS.

HOWEVER, a local Buick dealership said they can get a hold of one for me in about a week. So that just begs the question of whether or not my factory VSS will handle the larger gear. Like I said, my car right now has the 37 tooth gear with the 17 tooth drive. So would a 41/15 swap be just plug and play or would I need a new VSS to handle the larger gear??

 

The 700R4 / 4L60 can use either a cable drive or VSS depending which unit is installed
For any year /engine there are two VSS units ;
one does 35 - 39 driven gear and the other 40-45 gear.
As the later is generally unavailable ,the usual trick is to turn the former VSS 180 degrees so the shaft offset is greater to suit the larger gear

Running too big a driven gear on a VSS will quickly chew out either that gear or the drive gear

 

Short answer = Yup !

 

The answer I was looking for, thank you! The new gear should be in by the end of this week so I'll give it a shot and let you guys know.

 

Hey guys, I picked up the speedometer driven gear from the dealership today (cost about $18) and threw it in the car along with the gray drive gear. I flipped the VSS around like vetteoz suggested and it works like a charm now. Speedometer is spot on. I'm just surprised that the dealership of all places was able to get the speedo gear for me. Discontinued everywhere else! Must've been an NOS item they got a hold of for me.