View Full Version : C4 Speedo Gear???

04-13-2005, 03:35 PM
Can someone help me find the correct one? I have 3.08 gears and 255/60 -15 tires in the rear. I have tried many different ones with no luck. Seems like my only option is to get an aftermarket speedo that calibrates itself... but I'm not ready for that phase yet. Right now I have a 19-tooth Tan gear. Reads too fast! Thanks.


04-15-2005, 05:47 PM
egads i found the info. thought i'd share it.


04-16-2005, 04:37 AM
Each tooth added to the driven gear will slow the speedo approx 3 mph at 60.

Likely you'll need the 20 or 21 tooth gear....

05-09-2005, 12:15 AM
Use that TCI site to get your tire diameter. Then take that & your rear end ratio to http://novaresource.org/speedo.htm and see which driven gear will give you the correct speedo gear ratio with your current drive gear (which is machined into your trans output shaft so you can't change it like you can a Chevy's).

05-16-2005, 12:20 PM
darkthunder; u ever figure out which one to use? I recently bought my 88 and just got the speedo "working" ready waaaay to fast (can hit 100mph+ in 1st gear) the gear is yellow dont know the teeth. Whats the easiest way to figure out my rear end ratio? i dont know if its stock or what the previous owner put in...id hate to count the teeth on the gear and the pinion then divide that I think :(

05-17-2005, 11:53 AM
Jimfulco That guy on novaresource.org is to Nova's as Eric is to cougars...!!