Rear Axle?

[rgretzinger]

So I am trying to figure out what gears are in my real axle, whether or not it's limited slip or posi track, etc.. I know that this is probably a dumb question to most but I don't know where to look for this info. I have searched the vin codes and searched the site and no luck. I have a 10 bolt rear. Any help

 

[dhcomp]

If its stock, do you have an RPO code sticker in the glovebox?

If so, this will give you your stock gearing, and if there is a factory "locker"

The factory locker code is G80....if you have a g80 code, you have the factory (garbage) limited slip/locker. These tend to explode under moderately hard use.

The gear RPO codes are as follows:
GU4 3.08:1 GU5 3.23:1 GU6 3.42:1 GT4 3.73:1 GT5/GT8 4.10:1
Remember, only way to be sure on gear ratio is to open teh cover and count teeth.....as it coudl ahve been swapped since it was new.

 

[rgretzinger]

The sticker that was in the glove box dosen't happen to match the vin. My vin is cky184f153493.

 

[496truck]

The only real way to be 100% sure is to remove the rear cover and look at the diff and get the gear counts from the side of the ring gear. If the truck is mostly original you can get an idea from the build (RPO) codes in the glove box. Specifically look for "G" codes. ie. "G80" would denote the truck had a rear limited slip diff from the factory, most likely the gov lok. Do a google search for GM Truck RPO codes and find a pretty accurate description for most, if not all, of the codes.

edit: dhcomp beat me to it...

 

[82355]

Just pull your rear axle inspection cover. If you just bought it, changing the grease isn't a bad idea anyway. Then when you have it off you can see if you have an open axle, or a Gov-Lock. Also you don't need to count the teeth. The number of ring and pinion gear teeth will be stamped into the outer circumference of the ring gear.

Martin

 

[rgretzinger]

Yeah check the glove box again and there was the original sticker covered in dust in there. Weird thing was that there was an other vin sheet in there as well. Looks like it has 4:10's with the G80. Truck is all stock. Thanks for the help.

 

[pblaze725]

So I am trying to figure out what gears are in my real axle, whether or not it's limited slip or posi track, etc.. I know that this is probably a dumb question to most but I don't know where to look for this info. I have searched the vin codes and searched the site and no luck. I have a 10 bolt rear. Any help

I was wondering the same thing. My code was GQ1- STD but I couldn't figure out what the standard was for my rig. I jacked the rear end up & counted how many revolutions my drive shaft spun/ 1 revolution of the tire.
I got 3 1/4: 1 so I figured I had 3.08:1 gear ratio.
I didn't know there was a 3.23:1. Either way I need to change them out to 4.56:1 so I can run 35" tires.