Allison 6sp: LMM shifting hard

[Dorat]

About a week ago i helped a buddy install a transgo jr in his 08, 1-2 shift is hard, but the rest are crisp, downshifts while coming to a stop are hard as well. Hes put over 300 miles on it, i would think it should have relearned by now, i did the transgo on my 06 and it shifted perfect right from the get go. Only thing i can think of is, while installing the new trim valves, the red one on the other side popped out, looked to only be 1 spring the valve then the selenoid.

Didnt really want to have to pull it back out, pretty sure i didnt miss anything, but its always a possiblity. I was hopping it would just drive itself out.

 

[Mike L.]

Sounds like you dropped a check ball.

 

[Dorat]

Can i just replace it with another one the same size or do i need another kit, i work at a machine shop, we have tons of them?

 

[Mike L.]

As long as it is the same exact size it will work just fine.

 

[Dorat]

Well i pulled the trans back apart just now, found that the check ball did fall out, it was still in there behind the spring, put it all back together and now it shifts even worse, now it hangs, or revs then shifts and catches, downshifts are still hard. im at a lose right about now, only drove it a few miles so far.

 

[Mike L.]

Well i pulled the trans back apart just now, found that the check ball did fall out, it was still in there behind the spring, put it all back together and now it shifts even worse, now it hangs, or revs then shifts and catches, downshifts are still hard. im at a lose right about now, only drove it a few miles so far.

If you are sure you didn't drop the ball again; you will need the TCM to relearn the adapts all over again. Get a Tech 2 on it and reset the adapts.
Did you use grease when installing the balls and springs?

 

[Dorat]

only pulled one valve out, i could see the ball behind the spring, didnt pull the outer one out, didnt see a ball, springs looked to be under same tension, used a dab of vaseline to hold the ball in. tech 2 was another thought i had but made me real nervous the way it was shifting.

 

[Mike L.]

Never guess when diagnosing. I would have checked both valves.

 

[Dorat]

ok have it split right now, checked everything.. we noticed that one of the new springs from the transgo kit is longer than the other, is this how its supposed to be and if so what side is which. have it apart this minute, dont know what to do

 

[Mike L.]

Question is; was it this way upon original assembly or did it change after assembly. Springs are the same size. If they were different you should have seen this and stopped. Which spring; inner or outer?

 

[Dorat]

we got everything back together last night, deffinetly is alot better, only the 2-3 shift is alittle funny, now i think it just needs to relearn.