transmission snapping end off

[hydropkd]

I have a 1996 Z71 extended cab 4X4 with 38's on it and i keep on breaking the case for the transmission, wondering what the factory gears are in the front and rear end, and also is there a heavier duty trans that would work for me. dont take it in mountains much just road driving.
i have 10 bolt rear end, could i put different gears in front and rear and solve my problem of cracking case for transmission, any advise would be greatly appreciated....

[kenny-1907]

I used to own a 96 sierra 4x4 and it had 3:73's in it and i think yours might be the same which is an AWFUL lot of strain on the drivetrain with 38's. If you do a search on the silverado forum about gear ratios you will find a few posts in there about the codes on the sticker on the glove box door and what code is for what ratio. It might be possible that you may have 3:42's or even 3:08's in there, i am not too certain what was common those years. Although i must say that breaking the case is not normal and i suspect that you may have a seperate issue going on somewhere with a trans mount or maybe an engine mount. My brother was having problems with the cases splitting on the trans in his car and it turned out that the trans was hitting one of the control arms because of worn out upper and lower control arm bushings, not to mention over half the body mounts were broken from the torque that thing had. I would have a good look around at all the mounts and make certain they are ok. Just a thought.

[GOLIATHGMC]

You dont mention it, but I can assume you have a lift kit in your truck. Depending on how tall the lift is, you might have made the working angles in both the front and rear driveshafts too extreme, and you are binding the ujoints. Too severe of an angle can make for some hideous vibration, as well as undue stress in places it was not designed to be (such as where the T-case mounts to the back of the Transmission). You might look into a kit that drops the engine, trans and t-case down into the frame.
Also, if you do not have any type of traction bars on the rear suspension, the large tires have lots of leverage on the axle and can move the whole assembly around enough under load to drive the rear driveshaft into the t-case. This will also unnecessarily stress and wear out the leaf springs.
Hope this helps.
GOLIATHGMC