I did a search on this and didnt find anything to help me. I have an 89 Firebird with an electric speedo that needs to be calibrated. How do I go about calibrating it?? Do I just need to change the drive and driven gears or is there another way??


Thanks for any input!

 

Yes, the drive gear in the transmission and the driven gear on the VSS can be changed.

With the TH700-R4, the drive gear (on the tailshaft) selections are:

17T Blue GM #8640518
15T Gray GM #8642620

The driven gear (on the VSS) selections are:

45T Lt. Blue GM #9775187
44T Dk. Gray GM #9780470
43T Purple GM #1362196
42T Green GM #1362049
41T Yellow GM #1362195
40T Black GM #1362048
39T Brown GM #1359273
38T Blue GM #1359272
37T Red GM #1359271
36T White GM #1359270
35T Orange GM #9780628
34T Light Green GM #9774413

 

Thanks Vader!! I found out by using a calibration calculator that with a 15 tooth drive gear I would need a 48 tooth driven gear. The highest I see is a 45 tooth so would it help much to put the 45 in or do those 3 teeth make that much difference??