4l80e stays in 2nd after getting hot, no OD [Archive] - Diesel Place : Chevrolet and GMC Diesel Truck Forums

: 4l80e stays in 2nd after getting hot, no OD


erollinc
08-27-2009, 01:40 PM
1. Fluid level okay while running, warm, level surface.......... yes had it flushed about 10k ago

1a. Fluid color and smell........ not bright red, but nothing horrible... doesnt smell good or bad really

2. Speedometer reading correctly............ yes

3. Shifting normal/hard........... every now and then if it decides to go into 3rd really late (when its stuck in
2nd) itll hard shift.... other than that its fine

4. Shifting into OD okay?............ no it gets stuck in 2nd and occasionally 3rd and wont go into OD

5. Any service engine light: ...........yes/no no

6. If SES light on, what codes do you have?............ no

7. Model year:1995

8. Describe symptoms.............:doesnt come out of 2nd when hot, before operating temp it runs great... even if im on the highway it will stay in OD and be fine, but when i have to stop and go through the gears it will stay in 2nd and not go to 3rd or OD occasionally it will go into 3rd late ... but never OD when at op temp.... OH and my cruise control is also sometimes not working when the transmission isnt working but it worked fine b4 the transmission issues... so maybe a tps or related issue?

9. Does the engine come up to full temperature?,,,,, yes

10. Any service work recently done that may contribute to your issues..... no

11. Does the TCC lock up (or how many "shifts" do you hear?)........ im not sure... when its cold i hear 3
shifts .... when its not working i only hear 1 into 2nd

12. Are you experiencing any kind of slipping?..... no

13. What type of rear do you have? (Check RPO codes) 4.10/ 3.73/ 3.42 or 3.08............ it has 3.73

14. If you have an accurate tachometer, what is the RPM at 55 or 65?............ i want to say 2k at 65 when its in overdrive and alot when its in 2nd lol .... i can get more accurate figures if need be...

please help me! this is my only current transportation

GenBiltstein
08-27-2009, 05:00 PM
Let's do several things here. Go inspect your pass through connection into the transmission. Inspect it for leaks, pushed in pins. Broken, bent pins, Transmission Oil. If that passed good if not correct. New O-ring.

Test drive transmission in 3rd gear only. Good distance it would take you to get it hot. Does the transmission over heat? Does it stay in second when you slow to a stop and drive on? If yes then You need to test several things.
Transmission Fluid temperature sensor. It is the small grey thing inside the pan. It is a resistor. Read the sticky. Pin L and M. Research my posts and look for the same problem. Only if you know for a fact the transmission is not overheating.

If the transmission is overheating then several things must be looked at.
The transmission oil cooler might be restricted. Did you do anything to this truck? Is the transmission oil level full. Is it low??
Before you suspect restriction to the cooler drop the inspection plate and have a look see at the torque converter. Is it bluish in color. Is it discolored. Heat is developed at the torque converter.
Did you mod the OD. If you did then damage will happen to the torque converter piston. Reason why is because the computer must take it out.
The computer will take the transmission out of OD while in hot mode.
Check Radiator fluid level.
check for debris between trans cooler and radiator.
Check restriction at thermostat.

Check if there is an electronic fan to cool off the trans oil cooler.

PM me.