Allison 6sp: Need Help with Trans Problems

prostreeter600

Street rodder
Jul 18, 2010
895
7
18
Dallas Tx
Be forewarned this may be a little long winded but it is all pertinent information I think. So I had made some repairs on my truck due to melting down an exhaust turbine in my valley turbo due to exhaust leaks at the pedestal. I took it for a test drive where I decided to do a test hit, I put it in tune 5, engaged auto mode on the BT lock box, engaged 4x4, engaged Tow Haul Mode, everything I typically do at the track. I did a mildly boosted launch at about 20-25 PSI, it spun all 4 for a bit then it rocketed out of the hole hit about 100 and I shut it down. All went well, no more test hits as I told myself I would not run it at the track again till I installed my 3.42 gears. Fast forward---I installed the 3.42s front and rear. Once again I need to go test drive the truck to make sure gear install is good. No noise at all , all was good with the gear installs. So I figured do a test hit, did a tune 3 this time, did same as before to prepare for the launch, this time it left good again except that when it went to shift it flare shifted the 2-3 shift, I forgot to mention I do 2nd gear launches. So when it flared shifted I shut it down cause that was abnormal. I decide to drive it back home , I pull up to a stop sign and it wants to pull me thru the stop sign, upon further examination I see its stuck in 5th gear and won't down shift. I turned it off and restarted it, it's back in 1st gear, I drive it and now its stuck in 1st gear and won't upshift. I get it home put it in park, then put it in drive and it engages hard, same thing in reverse. I leave it alone for a while then try it again , now I put it in drive and it barely inches forward then acts like I put it in park, I give it the gas it will rev a little then like it defuels and it feels like its in a bind, it lugs the motor. I put it in park and it will rev no problem. So no check engine light. I assume it was the converter and replaced it. Got done with the new converter install and it changed Nothing. So could it be stuck solenoid valves ? I don"t think its the clutches just because I had no prior issues with slipping. Any help would be greatly appreciated. I know codes would be helpful, but the check engine light is not on so I'm assuming it hasn't thrown any codes. Thanks Again
 

WVRigrat05

Wound for sound
Jan 1, 2011
3,081
4
38
36
French Creek, West Virginia
I'm not sure on the Allison, but when I welded the clutches together in my 4l80, I had all drive gears, in neutral it acted like I had a trans brake and wouldn't rev, always under load, same in reverse and wouldn't move and park it would rev fine and had zero load.
 

prostreeter600

Street rodder
Jul 18, 2010
895
7
18
Dallas Tx
Starting to sound like welded clutches ^^^^^^^^^^. My symptoms are exactly as described above . As far as dropping the pan , I just did that when I changed the converter obviously. And yes there was very fine clutch material in the oil . When I opened the pan filter there wasn’t hardly nothing in there , when my converters has broken before there was a lot of metal etc
 

IOWA LLY

Yes, its really me
Feb 23, 2007
2,275
4
0
Sounds like you might have more then one issue. Whatever it is I would tear it clear down and go through everything.

Being stuck in a gear or binding sounds like a welded clutch. But try to pull through the brakes is the converter staying locked or at least dragging. It doesn't matter what gear your in it shouldn't try to pull through the brakes if the converter is working properly.


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prostreeter600

Street rodder
Jul 18, 2010
895
7
18
Dallas Tx
Pics

Pics of what I found on the pump cover
 

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prostreeter600

Street rodder
Jul 18, 2010
895
7
18
Dallas Tx
The last pic has the broken piece sitting on top of the pump cover . Question is would this broken piece cause the problems I’m having ? I also checked all the clutch sets . C1, C2, C5 clutch sets were pristine no hot spots at all and clutches looked excellent. C3 and C4 clutch sets looked like they have been slipping , they looked blackened, the steels looked blackened as well . 1 thin steel in the C3 set is warped. Anybody have any ideas as to what is going on with my trans ? Should I replace the broken piece , C3s and C4s and give it a go ? I’m gonna pull the valve body as well to see if there’s any stuck valves . I would hate to replace those items put it back in for it to just do the same exact thing again
 

Evan@InglewoodTrans

yerp
Vendor/Sponsor
Aug 5, 2010
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Western MA
The last pic has the broken piece sitting on top of the pump cover . Question is would this broken piece cause the problems I’m having ? I also checked all the clutch sets . C1, C2, C5 clutch sets were pristine no hot spots at all and clutches looked excellent. C3 and C4 clutch sets looked like they have been slipping , they looked blackened, the steels looked blackened as well . 1 thin steel in the C3 set is warped. Anybody have any ideas as to what is going on with my trans ? Should I replace the broken piece , C3s and C4s and give it a go ? I’m gonna pull the valve body as well to see if there’s any stuck valves . I would hate to replace those items put it back in for it to just do the same exact thing again

Never should of been a thin steel in c3. If you want to call Monday I can get you setup with what you need and go over what you have a going on.
 

Mike L.

Got Sheep?
Staff member
Vendor/Sponsor
Aug 12, 2006
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Fullerton CA
That broken keeper affected your C1 through C4 clutches. As Evan said, there should not be a thin steel in C3 or any other clutch. Thin steels can not dissipate heat and will warp.
 

prostreeter600

Street rodder
Jul 18, 2010
895
7
18
Dallas Tx
To be clear there are 5 steels in my C3 clutch set 3 are at .099 and 2 are at .067 . 1 of the .067s is warped and wavy no longer flat . My bottom Suncoast plate that holds the return springs is .231 thick and the top plate is .385 thick . So Mike is it fair to say that the broken keeper compounded the thin steels ? What does that valve control? The one with the broken keeper.
 

prostreeter600

Street rodder
Jul 18, 2010
895
7
18
Dallas Tx
UPDATE——I had multiple issues going on . The warped steel, overheated steels , and stuck valves in the valve body . Had to totally disassemble the valve body pull all the solenoids and valves then clean every nook , crany, orifice and part with brake cleaner and air blow gun . Success!!! It needs to relearn but feels good with the new parts I got from Evan . It appears to shift quicker and firmer . I got C3 & C4 setups from Evan . Thanks Evan . Also want to thank my friend & Engine/Trans builder Jason Walker . He talked me thru some hurdles I encountered. :D