CherryK5
1/2 ton status
What is the stock axle ratio in a 1994 3/4 ton pickup?
CK5
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3/4 ton ratio question
- Thread starter CherryK5
- Start date
Corey 78K5
1 ton status
Google RPO Codes. Then look on your glove box door for the codes that your truck was built with. There were several ratios offered. It should be a "G" code if I'm not mistaken.
CherryK5
1/2 ton status
I only have the rear frame section with the axle on it.
lectric80
3/4 ton status
There is no 'stock' gear ratio is the problem. There are a few different ratios that are available, and if you only have the back half then you are going to need to either count the rotations of the pinion while turning a tire, or pull the diff cover and count the teeth on the pinion and ring gear to get the ratio.
CherryK5
1/2 ton status
Damn. I was hoping I wouldn't have to do that. =/
They used to stamp a 3 letter codeon one of the axle tubes,noy sure if GM still does that or not..usually its never located where the books told you to look too!---I had to wire brush many an axle at the junkyard to find the code,if possible,it was better than pulling half a dozen diff covers off and counting teeth,spilling rank smelling gear lube everywhere!..our Hollander Interchange books had the listings for the codes,it tolsd what ratio and whether it was a posi or not..GM parts books at the dealer had the codes losted as well..I have one such book that covers 1946-72 10 thru 30 series..
Only way to be 100% sure is to pop the diff cover and count the teeth and do the math. Doesn't matter what was factory since anyone in the last 16 years could have changed it.
turn the damn driveshaft 
count tire rotation
3.42 three and just under 1/2 turn
3.73 just over 1/2 turn
4.10 just over 4 turns
4.56 just over 4.5 turns
4.88 etc etc
count tire rotation
3.42 three and just under 1/2 turn
3.73 just over 1/2 turn
4.10 just over 4 turns
4.56 just over 4.5 turns
4.88 etc etc
turn the damn driveshaft
count tire rotation
3.42 three and just under 1/2 turn
3.73 just over 1/2 turn
4.10 just over 4 turns
4.56 just over 4.5 turns
4.88 etc etc
You have that backwards, and have overlooked open diff function, as well as gov lock function.
One revolution of one tire would get you slightly over two revs at the yoke if it was 4.10. My 12 bolt with gov Lock and 3.42's gets me 1.7 turns of the yoke with one full turn of the tire.
Most factory gear sets are stamped with ring gear and pinion gear tooth counts. 41/11, 41/10, 41/9 etc. (3.73, 4.10, 4.56 respectively.)
Rene
I would still count the teeth and do the math. I have ran across two sets of gears that were either mismarked OR someone mismatched some gears.
People do some crazy things sometimes. As long as the teeth are counted AND it matches what is stamped in the ring gear then all is good.
CherryK5
1/2 ton status
Thanks guys! You have all been a great help. I'll just go ahead and try every method. hah =]
