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ALLISON down

THEFERMANATOR

THEFERMANATOR

FRANKENBURBAN
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Even the mighty ALLISON can be brought down. My BURB had been running PERFECTLY before my surgery, but the 1st time I drove it after my surgery it started slamming into 2nd. A friend came over today and helped me pull it out, and here is what we found. A torn C4 apply piston, and a set of C2 clutches FRIED crispier than the colonel could have made them. I had no symptoms or anything to point to a C2 clutch problem as my 3-4 shift was great, and it has never slipped in 4th or 5th(the 2 gears that use the C2 clutch pack), but they were DONE! The wierd part is the side that didn't have a kolene coated steel on it was almost brand new(the clutch on the left was in the same stack, just the one against a non coated steel), the sides against a kolene coated steel were GONE! Hopefully I can get some parts together and have it ready to go back in shortly.

C2's-1.jpgC4 apply piston-1.jpg
 
Wow. That is odd. When you did the build before, what parts did you use? Suncoast? What parts are you going to go with as far as the clutch packs? Hopefully your TC is still OK. I think that is the most costly part.
 
Someone's probably going to be doing more than his doctor would recommended. Lol

Sent from my Studio 5.0s using Tapatalk
 
That sucks, I know it is expensive to repair. Even if you do all the labor yourself.

Hope everything goes back together easily for ya! :thumbsup:
 
I had alot of help with it, but yeah the Dr wouldn't approve of this. On the other hand my truck needs to be running and driving to do me any good. I have no reason to believe my converter is bad or needs anything. The oter 4 clutch packs look great, this set came from SUNCOAST 3 years ago when I had to go back in it to try and smooth out the 3-4 shift. I also did the seal kit then to, so it isn't like the apply piston is old. It looks like I will be going back with a RAYBESTOS GPZ C2 pack, and an ALTO seal kit(ALTO is the only manufacturer that sells a kit with the correct C5 apply piston seals).
 
tanman_2006 said:
I don't even want to see inside of mine if that's what yours looks like!
Click to expand...

My other 4 clutch packs look new with 45K miles on them(except the C5's that have 210K on them). This clutch set only had 20K miles on them, so I have no clue as to why this happened.
 
I know very little about the inside of auto trannies but the one side being worn smooth off seems very odd. Is the filter plugged w/ junk after that?
 
I had no abnormal clutch material buildup or anything. I change my spin on every 10K miles, and have never had any noticeable buildup on my magnet either. This caught me completely off guard. I pretty well knew I had the torn C4 apply piston after asking Mike L, I expected maybe some burnt C4 clutches from it, but had no idea I would have C2 damage.
 
Ferm what else would cause a 5 speed ally to slam the 1-2? Friend has an 05 LLY that's got symptoms very close to yours.
 
is there a clutch pack that doesnt quite get enough oil? I remember seeing some PTO covers with curved fins on the inside to try to re-direct the splashing oil onto a clutch for cooling.

sorry to hear about the issues. definitely dont put yourself in a place where you can hurt the fresh reman hip!
 
3500GMC said:
Ferm what else would cause a 5 speed ally to slam the 1-2? Friend has an 05 LLY that's got symptoms very close to yours.
Click to expand...

If it is just the 1-2 shift then most likely it's a torn C4 apply piston, burnt C4 clutches, or delaminated C4 clutches. 2nd gear is the only gear that uses the C4 clutch pack in a 5 speed(6 speeds use the C4 clutch in 6th).

GM Guy said:
is there a clutch pack that doesnt quite get enough oil? I remember seeing some PTO covers with curved fins on the inside to try to re-direct the splashing oil onto a clutch for cooling.

sorry to hear about the issues. definitely dont put yourself in a place where you can hurt the fresh reman hip!
Click to expand...

The C3 clutches are teh ones prone to lack of oiling, but mine look great. I may go ahead and get a set of the GOEREND PTO covers and put in while it's apart as you have to have it torn down to drill the oiling holes for the PTO covers to work.
 
I would guess the coated steels have more friction than the non coated steels resulting in the uneven wear. One a clutch pack starts to slip they fry quickly. Just nowhere for the heat to go. And once slipping you have to cut power for them to get the higher holding power of static friction vs. the slipping friction.

Maybe you need to cut more power during shifts so the clutches can lockup before getting full power on them?
 
WarWagon said:
I would guess the coated steels have more friction than the non coated steels resulting in the uneven wear. One a clutch pack starts to slip they fry quickly. Just nowhere for the heat to go. And once slipping you have to cut power for them to get the higher holding power of static friction vs. the slipping friction.

Maybe you need to cut more power during shifts so the clutches can lockup before getting full power on them?
Click to expand...

I already have massive defuel in my tuning to protect my drivetrain. And the ALTO clutches are made of a material that is designed to be able to be slipped and still hold up. The stock friction would be toast after slipped, but the red eagle material should be bale to take it. The only explanation that I have received is the wave plate I was using to soften my 3-4 shift has proven counterproductive to the C2's holding up. I have NEVER slipped, limped, or even put big power through this box, so I just don't understand why this happened. This is teh same pack that 1000HP+ sled pullers are using, and they last for them.
 
Is it possible the clutches were dragging when commanded to be released and wearing out from the drag? Partial trans brake effect... Warped steel or clutch running you out of clearance, binding on the fingers, restricted release path, or apply pressure leaking into the clutch? Would the torn C4 apply piston leak into the C2 area causing them to partially apply? Just guessing and throwing out of the box thinking at it.

You sure the clutches are compatible with the trans oil you are running? I have seen Eaton posi clutches eat itself alive with GM synthetic factory fill as Eaton recommends non-synthetic... It took GM years and several oil revisions to figure this out.

The only other thing I can think of is low pump or apply pressure. Would the torn C4 seal cause a line pressure drop for the C2 pack? How much slip can you have before the ECM catches it and limps the trans?
 
The C4 has nothing in common with the C2 in a 5 speed, only the 6 speeds enagage the 2 at the same time. I cannot for the life of me come up with a reason for this to have happened. Fluid isn't an issue as my C3 and C4's use the same exact red eagle clutch material against kolene steels. And I checked them and every single clutch disc is exactly at factory thickness after 45K miles of use. I just cannot explain it, and the fact that the 1 clutch is burnt on one side but perfect on the side against the non coated steel is really puzzling since the other 2 clutch packs that use teh same clutch material against the same kolene steels are perfect after more miles.
 
Got it back on the road today. Replaced the C3 and C4 molded pistons, C2 clutch with the new RAYBESTOS clutches, a gasket and seal kit, and I had 3 gallons of TRANSYND in a open pale I used in it. Gotta drive it for a few days to let it re-adapt, but the 3-4 shift is some kind of serious now. It has never taken this long for it to adapt out on the 3-4 shift. All of the others took 2-3 shifts and were pretty good, the 3-4 must have taken a good 20 shifts before it started to get to what I would call civilized. Hopefully it holds up for awhile this time.
 
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