Just picked up a 92 RS. The previous owner swapped 3:73 gears in the rearend so the speedometer is off. What needs to be done to recalibrate the speedometer? How much would it cost to have a shop do this? Or is this something I can do myself?

 

if it is the same as my 93 which it prob is you have to change the gear in the tranny and probably the sensor as well.

Don't ask me the actual gears with teeth number or part numbers etc. but mine was off ten mph and I had to go to a smaller gear and the offset speed sensor.

 

there is a tech article describing the procedure, as well as part numbers for the gears, etc, over at www.thirdgen.org

 

I have 3:73's and had to change the output shaft gear to 15 teeth and I think a 43 on the sensor..........
http://www.tciauto.com/tech_info/speedo_gears.htm

 

Here's another good link for a step-by-step of swapping the speedometer gears:

Auto: www.sethirdgen.org/vss.htm
Manual: www.sethirdgen.org/t5speedo.htm

 

if everything beside the gears in the rear are org then u can not change speedo gears, hense u do not have any in the tail shaft of the tranny, u would have the vss sensor there, u will have to do like what i did in my 91 z was get a sgi 5 box and install that, not that hard to do at all, just do a search for dakota sgi 5 and u will find it,thats basicly all u can do with it sence there are no speedo gears to change, pm me if u need more info or help

 

Not true. Even though the 90-92 Camaros use electronic VSS's, there are still 2 plastic gears in the tailshaft of the transmission that can be changed out, very easily I might add. There is no need for the Dakota box when you can get the speedometer gears for less than $20 at any GM dealership.

 

i did not know that, i took mine too 2 different tranny shops in my city and they both told me there were no gears in the tail shaft and basicly there was not much they could do with it, thats when i found out about the sgi 5, i thought the vss took reading from magnets in the tail shaft and send volts in + and - to the ecm for it to calibrate the correct speed, hense i figured there was magnets in there instead of the gears

 

It's funny you mention that, because that's exactly how the T56 6-speeds are in the 4th gens. They just have a metal "gear" inside the tranny and a sensor just picks up the magnetic signal (or something similar to that). Kinda like cam and crank position sensors, and ABS reluctor wheels.

The electronic VSSs in the 90-92 Camaros is also similar to that. The VSS is technically just a "permanent magnet generator", and is really just 2 magnets, one spinning and one stationary. But, 2 plastic gears in the tranny are still what spins the magnet in the VSS.

 

ok makes sence, thanx for clearing that up for me, i was half right lol