I've got a built Allison in my LBZ that was built by Josh H. At top notch garage in February of 2019. Has 26k miles on it since rebuild. Truck makes about 530whp if I had to guess. Trans has been great but for the last 5 or so months when the trans is cold in the morning it will flare really bad from 1-2 shift and slightly from 2-3. Once it makes 3 or 4 up shifts it's fine. Holds power great. I have checked fluid level and it's perfect. I spoke with Josh about this a few months back before my warranty was out and he told me to bring it to him but I messed around and waited to long and now my warranty is up so that's on me. Was a bit difficult to find someone to follow me damn near 3 hours away to drop it off. Anyways anyone have any ideas?
Built Allison 1-2 shift flare when cold
- Thread starter LBZ_Baker98
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I plan to give him a call on Monday. I own a shop down here in Texas I just haven't spent a whole lot of time in side an Allison. I have helped build one before for an LML but with out any codes I'm not sure where to begin as far as diagnosis goes on a shift flare! Also just wanted to clarify this post was in no way to be degrading at all towards Josh H. He builds a great trans and was an absolute pleasure to do business with!
I have, the trans tune is only been adjusted for TCC slip inhibitor. But it does it with stock TCM tune as well. Also have tried 2 different sets of ECM tunes and no change.
Will get some Allison branded filters ordered today and do that next week. That comment kinda scared me though lol. Surely I haven't toasted clutches in a trans rated for 750ish with a 530whp truck in 20k miles. But yah never know I guess. Thanks for the input. Open to any other suggestions as well!
My opinion:
If you're messing with trans tuning and running different engine tunes all the time -- with no time allowed for the trans to learn them -- then yeah, you could've caused a problem. Could be a lot of things....
I would've also talked to Josh first before posting a public thread about the problem, too. Even if it wasnt meant to be a slight, it sure can be perceived as such. As a shop owner, would you want someone to do that to you?
If you're messing with trans tuning and running different engine tunes all the time -- with no time allowed for the trans to learn them -- then yeah, you could've caused a problem. Could be a lot of things....
I would've also talked to Josh first before posting a public thread about the problem, too. Even if it wasnt meant to be a slight, it sure can be perceived as such. As a shop owner, would you want someone to do that to you?
110% agree with Bac and Mike. Drop the pan and see whats going on... talk to Josh, he has helped me go through these things over and over again to the point were I am finally comfortable building my own.
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What these gentlemen said. Give Josh a call first, I doubt he will tell you to kick rocks.
And to Tom's point, I agree, swapping trans/ecm tunes constantly isn't doing anything any favors. The trans needs to relearn in order to get shift timing correct. I'm not saying that is the problem but its not the greatest practice to constantly swap tunes for fun.
I'm aware of the trans needing to learn. Too be clear I don't swap tunes everyday. Every couple months I'll flash a different set just for the hell of it but that's it. I always give the trans time to relearn. Again this post was in no way meant to make Josh look bad. He was more then willing to take a look at it for me when I spoke to him a few months back. I didn't manage to get the truck to him before the warranty was up and that is 100% my fault. At this point im interested in learning these transmissions and figured I could get some insight on here and possibly fix it my self. If it were to need a full rebuild or a new set of clutches for some reason I'd probably tackle it my self due to the soul fact that that's the only way to learn it seems.
If you bring the truck to me, I would still be willing to take a look at it and see what’s going on.
Thank you Josh, again didn't mean for this post to seem like I was taking any shots at you! Was just thinking it might be something simple I could take a look at and possibly repair my self. I'll give you a call on Monday!
I'd be interested to know the outcome of this.... Mine is doing pretty much the exact same thing. I always assumed I hurt it when I was screwing around with a 6 speed VB and a butchered internal harness being run by a 5 speed tcm or something along those lines. Or maybe an apply piston leaking just enough to drain while sitting but be fine once 'charged'. Aside from the flairs on the first two or so 1-2 & 2-3 shifts, its been perfect with no issues, even pulling 10k+.
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Unfortunately I have been slammed at the shop and haven't had a chance to call Josh. The truck gets driven maybe 5-8 miles a day so I've just been letting it sit and idle for a bit before I leave and being easy on it! Hoping things will slow down this next week and I can get it to Josh!
I'm also having this issue come around sometimes. My trans is a complete stage V from PPE with 100,000 miles on it. It will flare sometimes on the 1-2 and the odd 2-3. Fluid looks great but Im thinking its possible the torque converter that came with it is whats contributing to the issue. It blows right through the converter on anything over my half throttle. Someone correct me if im wrong but the trans came with a white triple disk with i believe is a Precision Industries ML converter without a billet stator?
I have a Limitless 1078 coming and should be installed by friday next week so we'll see. Whats everyone else running for a converter that is having the issue?
I have a Limitless 1078 coming and should be installed by friday next week so we'll see. Whats everyone else running for a converter that is having the issue?
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You think the trans needs a rebuild? Its never been abused badly usually lives on a 100rwhp tune. The Converter though has seen a few boosted launches on the street. Trans is from 2012.
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