96 Tahoe Tranny Issue

[nymiskovics]

I have an issue with the tranny on my 96 tahoe. it is a 4l60e trans. A couple of days ago, the posi pack in my rear axle blew apart and destroyed the inside of the axel. I put in another rear axel, and it works fine. However, now the tranny wont lock in to gear of I put it in drive or third. If I put it in 2nd, 1st, or reverse it works fine, and as soon as I get moving I can put it in drive and it shifts fine, as long as I dont let it downshift all the way to first. I can also hear some kind of faint noise from the tranny when I shift into drive from park, neutral, or reverse. The transmission was rebuilt three years ago and I have had no problems until the rear end gave out. Any ideas what could have happened?

[rodram]

... you have lost some shift bands in your transmission ... likely the 2-4 band, plus other parts..

 

... Your truck endured some form of hard use (I won't assume abuse) before your G80 Eaton Locking Rear Differential (technically it is not a posi-) blew up... this hard use likely also caused a lot of stress inside the transmission ... the greatest enemy of these transmissions is excessive heat ... if you work them too hard you start to lose the 3-4 and the 2-4 bands ... and then when the transmission starts to slip it gets hot, the more it slips the hotter it gets, and the internal damage progresses.

 

... get it to a transmission mechanic.... but I'll bet the diagnosis is... total rebuild required.