Well I burnt up the second set of 456 clutches. If the tune isn't the issue, what hard parts or seals would cause this failure? Rebuilt the trans with Sonax zip kit, up graded both Pistons, high rpm spring, all new bushings and seals. Even used a dial indicator to test the travel of the return springs. Flushed trans cooler and had converter cut/cleaned. The tuner had my truck pulling harder than it ever has and felt solid. Then a month later it started slipping then 2 day later they are toast?
2013 crew cab half ton. 5.3 turbo 3200 circle D trip disk. 450/480 hp/tq.
Anyone been here?

 

First 3 gears still shift good

 

What brand clutches did you use? Is there any wear on the 4-5-6 hub, how do the 3-5-r clutches look? What do the other two reaction drums look like?

 

GM stock first set Raybestos stage 1 second set

 

Haven't got the trans apart yet. I'm going to start tonight

 

could be a pressure solenoid on it's way out or a torn laminate.

RT

 

Can you test the solenoids and switches?

 

Yeah with a plate the tcm bolts to that you put air to, and control it with a scan tool...i am sure there is another procedure but i am not familiar with it...

 

electrically you can take a Fluke Meter and check the operation. Sonnax has a video of how to do this and it's very easy.

RT

 

I thought that was just to check the resistance? Maybe i need to watch that again when i am not half falling asleep....