: Transmission help

05-16-09, 08:18 PM
Hey, here's something rather fun that happened today. I have a 01 deville northstar 4t80. Had a 1860 tcc open or short. so today I replaced that tcc solenoid and the pc solenoid while I was in there. Went well, was working great, no codes good lock up. I'm on the highway in 4th and lock up, then it redlines. coast over to the side of the road. Not making any bad noises, no reverse or any forward- in drive or any manual gears.Could it be a broken oil pump shaft? Does that sound like my problem? or is it used tranny time? the level is low I notice but..
thanks for any tips!

05-19-09, 06:45 AM
the fluid was only down a quart, still nothing:mad:

05-19-09, 01:39 PM
Get the car towed home or to a garage and drop the pan. That's the only way to tell if there is severe damage or not. Also disconnect the top transmission cooler line and see if there's flow out of it with the engine running. If the pump is working and there aren't any clogs, there should be flow. If the damage isn't bad, you may have to go back in and retrace your steps. Maybe you mixed up a couple check balls or something.

05-24-09, 01:41 PM
I found the problem...
There is a bracket on the side cover of the trans, for one of the mounts. It is held in by three m8 bolts and one stud. The stud LOOKS like it should go in one way because it is too long the other way to even get a deep socket on. So, I put the bolt in the wrong way first, then flipped it around when I realized that it was too short to put the mount bracket back on. By putting the bolt in the wrong way it broke off chunks of aluminum off the backside on the case. The pump picked up one of the chunks, locked and broke the pump shaft. Initially, I had no idea why the pump shaft broke but when I went to another gm dealer to talk to a couple of my trans buddies, they knew exactly what I did. "ha, almost everyone has done that once".
I removed the upper valve bodies, both pumps and channel plates apart and cleaned all the $hit out. Dropped the pan and cleaned it too. Has been fine since.
I admit I f'd up big time, learn from my mistake please.