Drivetrain Stress

hockeypro1411 · June 16, 2013

Just like the title implies, the 2003 has been parked for repairs. (Used this as an excuse to buy a 2005 Duramax though ). Long story short, my rear u-joint decided to fling out the retainer clips while I was doing 70 on the highway and I had a catastrophic drivetrain failure. Replaced the u-joint and drove on, but a few days later I noticed some ATF dripping ever so slowly from under the truck. I determined it was coming from the gasket between the t-case and the tail shaft housing on the transmission. I decided as long as I was that deep, the t-case was due for the pump upgrade. With the help of a buddy, I dropped the transfer case, and that's where the fun ended.

The gasket mating surface on the t-case is all different kinds of corroded..

And upon further inspection, the thrashing of a rouge driveshaft apparently left a nice stress crack in the tailshaft housing on the transmission.

Now, I suppose this is aimed more towards the guys who've been inside a 4l80E.. If stress was enough to crack the tailshaft housing, what are the chances something deeper inside the transmission was affected? Also, where are guys buying transmission parts from? I found a couple places, but there prices were over $50 different for the same part.

MikeNH · June 16, 2013

I had a friend experience a similar failure in his 2006 Duramax. Cracked the bellhousing and the aluminum adaptor on the block. He's repairing it now.

hockeypro1411 · June 16, 2013

Dropping the transmission is kind of a last resort, but if it needs to be done, it needs to be done. Like I mentioned earlier, I bought myself another truck, so the 2003 is sort of just a project now anyway.

gmtech4 · June 18, 2013

change the adaptor ,i doubt very much anything happened inside ,,,change the t case front half,,its done,,,ya need all 3 seals as the front output shaft and front input shaft retaining rings are behind the seals ,,front output is a 2 pc seal and a PITA to get off