I have a '99 Olds Bravada and just recently aquired a '93 Chevy G20 Van, both have the problematic 4L60E transmission... The transmission on the Bravada went out at around 76,000 miles (I lost reverse and the vehicle wouldn't shift out of second gear) - I now have 126,000 on the Bravada and it's beginning to act up again... When I am in Overdrive and decelerate to cruise between 30-40 MPH, the tach begins to fluctuate between around 1600 RPM and 1700 RPM (more or less) and the vehicle feels like it's surging... whenever this happens I manually shift into 3rd because I know this shouldn't be happening. I can't for the life of me figure out what the problem might be, but I'm afraid the transmission will be going soon... Also, as if that weren't enough... two days after purchasing my G20 van, I noticed the transmission trying to "catch" while shifting into Overdrive... it would bang into gear after anout two seconds of trying to shift and you could feel it shake the whole van. Finally, when I was driving home, a particular "bang" put me down into second gear (as far as I could tell) and the vehicle would not shift out of second... I tried moving through drive and OD manually but to no avail. I limped home with the van, but just yesterday I started her up and it was shifting fine for about 2 minutes, then went back into second again... I haven't checked to see if reverse is working or not on the van since this last occurrence, so I'm not sure what the deal is with it. I'm extremely frustrated with this transmission... and any advice would be greatly appreciated.

Thanks,

 

OK, start with the easy stuff first. Check the fluid level. 4L60 trannies are VERY sensitive to a low fluid level.

Secondly, has the tranny had it required services done? At 120K miles, you're probably overdue.

Finally, 120K on a tranny, any tranny, is pretty good. It just might be time to rebuild it.

Good luck with your issue!