ALLISON TROUBLE?
 

Lets use this one to talk about any trouble out of the LMM allison, stock or otherwise. Include HP/TQ numbers to help others. Thnx:U:

Are you having issues?

No issues yet. I was wanting input on peoples expieriences and noticed there wasnt a section. Just trying to get people to share maybe their mishaps and issues, as well as finding the "limits" on their combos as well as how far the stock ones been pushed. Knowledge is power which is why were all here:c:

Well nice post, and it should help many. We have found 430 rwhp to be a strong number that they can live nicely at. Much more and they start limping.

Somebody,anybody! Whats breakin'? Whats holdin'? What are ya runnin?!?!?

Mine held roughly 500 rhwp for about a week before its first limp. This is with alot of hard driving. Normal tuning put me about 400 that is where the most abuse was., that was ran for approx. 15000 miles.

i work at a tranny shop and reverse and 1st and second ar the problem areas becuse of the valve body

In the Allison's? 4th and 5th I believe are the weak links because of the pressure the C2 clutch pack receives. I actually think 1st and second are close to bulletproof

The six speed holds a lot better than the 5 speed. Very easy to limp the old 5sp with a conservative tune even. The 6 speed can take a thrashing if you have a tune with defueling between shifts..

I thought 1st and 3rd were the weak points.:humm:

Yep... I just learned that. With the Bullydog tow tune +50RWHP +100ft-lbs, my truck runs fine. But honestly, that's the limit. I put it in performace mode (+75RWHP +125ft-lbs) and it limped in the first full throttle run I did. I was running the truck more or less empty, just me and 400lbs in the box and it limped in 4th gear. This was after 2 weeks of being driven in Performance mode with adequate time for the Allison to re-learn wtf was going on. :s: Back in tow mode I went... :sadnow:

I'm envious of you guys with the newer 6 speeds. I wish I could make those power numbers.

Ya its that 4 to 5th that'll get you. Then it locks in 4th and no reverse till ya cycle the key and the code is set..When I had a Bullydog I also got a 621 code I think too , never did figure that one out... A BD Programmer will limp a 5 speed on 70hp tune sometimes. Looks like ya need a suncoast upgrade , If its the first limp you have had your still ok for a while, if it keeps happening eventually it will do it on a stock tune...Did it freak ya out when it slammed into limp? :jump:

lol I was half-expecting it to limp actually. Just from stories I've heard, plus my truck isn't virgin anymore with over 200,000km on it now and it's done its fair share of 5th wheel pulling. I made sure I was on an empty street, and floored it from the green light. I was happy to make it past 3rd gear with no trouble lol... But when it happened I was disappointed only in how easily the transmission can be limped. Seeing it down shift and redline from like 62mph was nuts hahaha. Pretty stubborn about it! After that I cleared it and put it back into Tow/Economy. Better safe than sorry until I can pay to play!
Sun Coast is now on my wish list haha. :c:

ya i can make it from 1-4 full throttle on level 5 with my edge. if i stay in it too long it will limp right before fifth. if i let off and let it shift to 5th and slowly lay back into it i have no problems. :tu:

With my hot tune on my stall will not hold lock up. She shutters some, this is a 08. Other than that she is great. I have about 500RWHP. But zero codes and zero limp mode so far. I put a deep pan on and shift kit be for any tune was added.

Skydog:rocking:

All changes from stock are in my sig. I will say though, that I have never gone into limp mode, and have never noticed my tranny slip. Yet. It will happen as the power goes up, but once again, driving habits, along with the deeper pan, good oil, regular oil and filter changes, and the shift kit have helped to keep my tranny running cool and smooth, although only with about 370rwhp right now. One of these day when I decide to push the 500rwhp mark, I will first have to drop 4k on a tranny upgrade. Either PPE or Sun Coast. I have toured the PPE shop in California. Really good guys and they are diesel owners and lovers. Yes I bought the T-shirt:)

Stock my 0-60 is 8.0 seconds and when I added 100 rwhp with my chip the best I got was 7.6. It seems like the shifts take a lot longer. The truck feels much quicker in every gear but the shifts are slower it seems. So in the end my truck isn't really faster. Is my transmission going?? It's got 100,000 miles on it and I got the truck a week ago so I dunno what it was used for before me. It was totally stock and in almost new condition and I would have a hard time believing its been driven super hard. I don't know much about gm because I've always been a dodge guy til now. Does anyone know what the problem is??? Or what I can do to fix that??

Did you do a tranny re-learn with your tuner? Not sure which tuner you have, but PPE told me when I was down there in 2010 that if you move more than 2 power levels, always do a tranny re-learn on the tuner. Also, don't do any highway driving on the re-learn either. They had me go from level 2 to 4, and told me to just drive around for a hundred miles in the city. In LA, that ain't hard to do. I came back a couple of hours later and turned it down to 3 because 4 was just to hairy and EGT's were getting too high. When is the last tranny service as well? I do mine every 50k miles. If yours hasn't been done, get it done. While you're at it, get the Trans Go Jr. When they drop the valve body, it will say a lot I believe.

I put it back to stock and was going to see if I could update the chip but it didn't work so I put it back on the truck and now it shifts great. Someone told me it just needed to learn it first so that's why it took a bit for it to work well. I guess?? I dunno if that's true but either way it works great now. But that's tranny service is something I should definitely do and I've been thinking of getting the transgo aswell just to help the transmission last longer. Thanks for your help

I have an 06 lbz with only 89,000 and I'm pretty sure my c3 clutch pack is going out and the trucks completely stock. But to give it some credit it hauled 16,000 lbs its whole life