1985 gmc high sierra

[nford824]

hello, im new to this site and im trying to get my 85 gmc back on the road. Its a 6.2 diesel with a 700r4 transmision 4x4 all origional. The transmision case broke around the tailhousing so i need to get a new one, it didnt brake from impact or anything im guessing its a bad design or the driveshaft shaking around, and its had multiple transmision replacements in the past, more than it should so i dont want to make the same mistake and have to buy another one in a few years. Has anyone else had this problem? Should i switch to a diferent transmision? Are ther modifications i should do to fix the problem? Any input would be appreciated, thanks

[nford824]

come on guys

[NitroCherokee]

I have seen this happen on that era truck, usually it was caused by a bad u-joint, it doesn't take too much of that shaft vibrating just right to break the aluminum housing. I have seen it happen to TH350 and TH400 trans too

[txab]

Get the transmission rebuilt, driveline checked and balanced. Check your angles since you've got a 4x4 with I assume a lift on it

[Squirrely]

The transmission broke or the transfer case?

 

If you're running a 4x4, the transmission output doesn't connect to the driveshaft. It connects to the T-case.

[nford824]

i believe its a married t case, not a high boy

[nford824]

and the t case is busted