GM 3.73 Gears ?s

joshp007
12-29-2004, 11:06 PM
I have heard that if I have a GM set of gears 3.73 that I wont even need a install kit to put these in my 95 Z. Anybody know if I can just swap these out?

Pro Built Automatics
12-29-2004, 11:13 PM
What gear ratio are you replacing with the 3.73's?

blown94
12-29-2004, 11:16 PM
No its not that simple. I just swapped out 3.23's for 3.42's and now the backlash is so tight I get gear mesh noise at higher speeds. Basically, theres not enough space between the gears for lube. You'll need to shim the carrier at the very least to obtain .005-.010" of backlash and unless you've done one b4, you'll need a dial indicator to figure out how much that is. You may have to adjust pinion depth also, which is a little tougher without the right equipment, but more than likely, if theyre GM gears, you can just re-use the shim under your stock pinion bearing and you should be ok.

joshp007
12-30-2004, 10:41 AM
Ok thanks, I am replacing 3.42s

Pro Built Automatics
12-31-2004, 03:34 AM
The install kit is a excellent idea, and you should have a dial indicator. If you have never done one before, you should have someone who has done this to help you out on how to read the drive & coast patterns when setting the pinion depth. Run the preload & backlash recommended for your particular gear set. Lucas is good fluid, & use the GM posi additive. I hope this helps.

joshp007
12-31-2004, 10:34 AM
Helps a lot! Thanks