'00 Chevy 2500 4L80E Issues

[jeepinmatt]

Truck is new to me, bought it with a non-working transmission. Transmission has been rebuilt and reinstalled. Now its having TCC lockup and shifting issues. Yesterday once I got a little heat in the transmission, it was stalling the truck when put into any gear (forward or reverse). When you initially shift it is fine for about 2 seconds, then the TCC starts to lockup and if you have your foot on the brakes it will stall out the engine. I drove it around probably 50-60 miles today. Current symptoms are as follows:

1. No speedo at all. I replaced both VSS's at rear of t-case yesterday, and all connectors are plugged in.
2. ABS light on
3. "!Brake!" light on
4. Trans temp gage jumped from no output up to 150, then fluctuated around
5. Truck will generally shift through all 4 gears, and locks up in 3rd and OD. Occasionally it will not lockup at all when OD is selected, but when pulled back into "D" it worked properly.
6. Shifts are extremely firm, but not jarring in 1-2-3, except into OD. Sometimes it shifts firmly into OD, other times I wonder if someone just hit me from behind.
7. After about 15 minutes of fairly easy driving on a 40degF day, the trans temp gage was at 200degF.
8. Now instead of stalling the engine when put in D or OD at a stop, it bogs it down to about 3-400rpm and seems to fluctuate. When put in R it still stalls the engine completely.

I'm planning to drop the pan later this week and replace all of the solenoids that I can get to from the bottom unless someone has a better idea.

Thanks in advance!

 

[transman731]

it sounds like you have a lot going on here.
were the codes cleared after you installed trans?
did you check the speed sensors on the trans?

it sounds like you have a pump issue. the first thing i would suspect would be the pressure regulator system. if the pressure regulator valve is worn it will let converter release pressure leak through and not fully release the converter.

the first thing i would do is take it to whoever rebuilt it so they can put a pressure gauge on it and see what's going on.

 

[drummin'jeeper]

Just Saturday a friend of mine was complaining of the exact same issues hard shifting and all. He had someone scan it. The tech told him to get an ABS sensor and brake light switch. I put them on since that is what he brought me. He's put 280mi on it since and the problems he was having has gone away. He said night and day difference. I don't know. He was going to drop pan and everything too, but I told him to start with the cheap/easy fixes first.