Alright just had a cam and converter swap done on my 05 silverado ecsb 4x4. Got it back and it wouldnt hold an idle when warm so I had it tuned. Went to a local guy for tuning (rob aka RKTuning) and drove the truck with him for about 4 hours ironing out the tune. He did a great job and gave me a nice street tune to my liking using hptuners. Drove the truck home fine. Woke up and drove the truck all day fine. Then things got ugly on my way to work in the afternoon...

While driving the trans lets go and im free revving as if I am in neutral and the truck will not move. If I shut it down and let it sit for a couple minutes then start it again it will go into gear fine, shift fine and drive maybe a mile and then the trans will let go again and the truck will free rev but wont move. I checked the fluid and its clean but the level was VERY high. I siphoned about 3.5 quarts of trans fluid out, but that didn't help. Could this be a tuning issue or is something wrong with my trans or converter????? Please help

 

It won't move in any gear? What was the clearance between converter and flexplate before they were bolted together? Does the fluid level change between running and not? It should go down when running unless the pump is damaged. Could put a gauge on it to check the line pressure.

 

Sounds like a bad converter install to me leading to trans failure.

 

@DrX it moves in every gear when I first start the truck and put it into gear. I can pull out and start driving and the trans will let go and I'll just be free revving. Then i cant go anywhere, but if I shut it down and wait 2 or 3 minutes I can start it back up and it will go into gear again fine. Then it will let go again while I'm driving.

 

my buddy who did the install thinks its a tuning issue, but my tuner thinks the excess fluid in there ruptured seals or ruptured a trans line and isnt allowing the pump to move fluid properly.

no leaks and the fluid is clean. Also what gets me is I drove the truck home fine after the install (15 miles). Next day it drove fine (15-20 miles). Later that night it drove fine to the tuner (10 miles). Drove it all night fine while getting tuned for 4 hours. Drove it 10 miles back home and it was fine. Drove 15 miles to and 15 more miles from a job interview the next day. Then, on my way to work later in the afternoon I probably drove 5 miles before the trans randomly let go and I was free revving not going anywhere. No warning sign, no noises, no leaks...just happened.

 

Did you read the fluid level with it running and warmed up? It will read high if not running or if the pump is messed up.

If it is the pump all gears will be affected.

It is possible to fry clutches if the tune is commanding too low a line pressure.

If you unplug the main(round) electrical connector on the trans it should put it in limp mode. The tune will no longer be controlling it. You should then have high line pressure(if the pump is not dead) with 3rd, 2nd(manual select) and reverse gears. If it is the tune, the line pressure will be high in limp mode. If it is the pump, you will have low line pressure even in limp mode.

 

DrX, thanks for the limp mode tip. I did that and it moved a little better, and for a little longer, but its looking like my pump is shot.

Any recommendations on new pumps and where to get them? Would a stock replacement pump be sufficient or should I look into an upgraded pump since I now have a converter and a tune?