Allison 5sp: Possessed stage IV

[Kappa9012]

My Transmission is possessed!!! I've been struggling for two years to understand why I have a Harsh 1-2 and 3-4 part throttle upshift. The transmission is a Stage IV suncoast with a 1057 converter. It was just opened up two weeks ago to see if anything was really wrong inside and the C1-C3's were replaced. I'm running a good tune from Nick at DuramaxTuner, and the stock TCM tune.

All the clutch stack ups were good when the tranny was rebuilt. If I reset the TAPS the trans will shift good and smooth for a few shifts then learn itself back to shifting like ASS!!!

Any ideas?

 

[LarryJewell]

have you tried a different tune, and re-set the taps with the new tune

 

[Kappa9012]

all the TLIQ and TBIQ tables have been adjusted many times, and been set to stock.

One thing to note on the tear down two weeks ago was all of the Valve Body bolts were VERY tight, and we weren't sure why. When I built it the first time, i didn't torque them to spec but no where near this tight. we didn't remove all the valve body bolts for fear of breaking them off, but we took out the required bolts to pull the valve body.

Think that could be it? wouldn't it code, and is there a way to check the condition of the VB or do i just replace it?

 

[racinmike77]

take the VB apart and look at the valves, you will be able to tell if they are worn, clean everything very thouroughly, push on the valves and make sure they slide freely, and this time tq to 9ftlb.

 

[Kappa9012]

I'll give that a try this weekend.

 

[Mike L.]

Sounds like a problem with a trim valve spring or ball out of place.

 

[beach_33]

i told him it sounded like what my truck was doin mike. which ended up being the trim valves. all is well know. yo wont be getting anymore calls from me mike. that should make you happy