GGReactor

Not sure of how to word this, because I haven't had a problem like this before. I'm gonna try to get in some small things that may be related to the problem, but like I said, I really have no idea lol so please bear with me.

Well, I was driving down the highway in my fiance's Tahoe and when I got off the highway I noticed the the transmission not really downshift, but like, it felt like someone just hit a clutch in a standard and it just jolted and returned. It really drove fine until I got to my destination after that, although when I was pulling in I noticed I had a very slow reverse.

The next time I got into it I backed out with no problem, and started down the road. About a quarter mile down the road, the transmission lost power, as the engine was still running completely fine (I think) steady at 750ish rpms. So I turned it off, then turned it back on five seconds later, put it in gear, and it drove about another 30 seconds until it lost power again. The cycle has repeated and repeated ever since, I actually got my truck and towed it home to prevent further damage if any was being damaged.

Transmission fluid is a little ways above the max line, I'd say 3/4" above it, and we haven't added transmission fluid in a few months at least, the problem is I don't recall if I overfilled it back then, or if maybe the pump on the transmission went out, but before I do any serious work on it I'd like to see if anyone has any opinions.

It has also had small electrical problems going to the dash board, but this has gone on since we've owned it (about a year now). Also, one more thing, regardless of if I'm driving it or if it's sitting there, after the engines been running for about 30 seconds, it wont move. And when trying to shift between reverse and drive I don't hear anything engaging.

73shark

Welcome to the forum. The excessive amount of transmission fluid may be causing it to foam which could lead to the problem you have described.

GGReactor

Thanks for the warm welcome! I'm gonna try that today, I'm hoping that will fix it, not looking forward to pulling a transmission anytime soon in this heat.

And of course like any 4L60 the drain plug stripped, I'm gonna just drop the pan now, would you suggest at 250K miles to put a new filter in? If it's really messed up isn't it best to keep using the old fluid and such?

johng908

Had similar symptoms and turns out it was the 3rd and 4th gear clutch packs. Needed rebuilt trans.


When that happened I was able to shift into 2nd gear and keep revs at 3k to limp home.

GGReactor

I believe we figured out the problem and I just wanted to post this since I haven't really been able to find any info dedicated to it yet. Not 100% sure, gonna try the fix today and tomorrow and will get back, but I realized the rising fluid lever was NOT transmission fluid, it was actually ATF. I pulled the radiator and noticed a good mix of ATF and Coolant coming out, not sure if some of the internals on the radiator got clogged and pressurized causing it to bust or whatever, but I guess now my next goal is to flush the transmission, get a new filter and gasket, install a new radiator and pray for the best lol