4L80E whine and looses pressure when hot
Thread Starter
Joined: Jul 2005
Posts: 2,119
Likes: 610
From: Henderson, TN
4L80E whine and looses pressure when hot Truck is a 2002 2500HD 6.0 4x4 with truck cam and the tune has the line pressure turned up for firmer shifts....
Anyways friday night I was driving home from the river and after passing a car I slowly started to heard something that sounded like my power steering whining, I was still about 20 miles from the house so took it easy and the whine progressively got louder, I got about 2 miles from the house and it wouldnt pull from a stop unless I revved the engine.
Checked fluid and it was ok, had no choice but to limp it home and did alot of coasting, trans temp never got much above normal.
Got it in the driveway and shut it off, after it cooled it pulled fine again so i went down the road and after a few minutes started to whine again.
Pull it in the shop last night and yanked the trans out thinking it was the front pump, but the pump appears to be ok,
I dont really see any pitting or damage. The filter didn't appear to be clogged, and there was only normal bits of debris in the pan.
Any ideas?
Anyways friday night I was driving home from the river and after passing a car I slowly started to heard something that sounded like my power steering whining, I was still about 20 miles from the house so took it easy and the whine progressively got louder, I got about 2 miles from the house and it wouldnt pull from a stop unless I revved the engine.
Checked fluid and it was ok, had no choice but to limp it home and did alot of coasting, trans temp never got much above normal.
Got it in the driveway and shut it off, after it cooled it pulled fine again so i went down the road and after a few minutes started to whine again.
Pull it in the shop last night and yanked the trans out thinking it was the front pump, but the pump appears to be ok,
I dont really see any pitting or damage. The filter didn't appear to be clogged, and there was only normal bits of debris in the pan.
Any ideas?
TECH Junkie
Joined: Dec 2012
Posts: 3,620
Likes: 1,331
From: Iowa
"fluid level was OK"
ehhhhh that really sounds like the most likely issue based on your description
If you have the pan off...verify the "full" mark is correct...I've seen factory dipsticks be way off
Cracked filter, bad filter seal, etc can also cause issue
ehhhhh that really sounds like the most likely issue based on your description
If you have the pan off...verify the "full" mark is correct...I've seen factory dipsticks be way off
Cracked filter, bad filter seal, etc can also cause issue
