Okay, some of you might remember my thread about my injection pump blowing up. Well, I'm back with another bizarre issue. I'm certain this POS is cursed, but I can't get it to stay running long enough to sell the thing.
I have a 2006 LBZ. Bone stock. Well maintained (allegedly).
Couple weeks back, truck out of nowhere started shifting at a serious delay, as in it would shift at 2100-2300 RPM. It would also downshift really late, and sort of "jab" into gear on downshift. I pulled over, checked the fluid. Bit on the low side but plenty of fluid. It wasn't new but it was still quite red and did not smell burnt. The trans temp was fine, no overheating. No check engine light came on.
On that same day that started happening, I drove home and noticed a puddle of ATF on the ground where my truck had been sitting, and had idled at for a good 10~ minutes.
I didn't have time to fiddle with the truck, so I let it sit for about three weeks. In that time, no more fluid leaked out of the tranny.
I then put about maybe 1/3 of a gallon of ATF in and got it to a reasonable level, and drove the truck to a local well respected transmission shop. They don't specialize in Allisons by any stretch but do deal with them somewhat regularly.
They hook up their pro scantool, absolutely no codes thrown. They find the leak to be a seal on the top bellhousing bolts (or something of that matter), so the trans gets dropped and those get replaced. They then reset the TCM (I believe), and the transmission goes back to shifting fine at the factory default setting. As well, they do a trans service (drain/fill new fluid, new external filter).
I pick up the truck, pay a hefty bill relative to work performed (something I have become all too acquainted with lately). Truck did shift fine. I drive maybe 80 miles (possibly not even), and the truck suddenly goes back to the exact same late shifting problem. No leaks this time. No codes thrown. I call the trans shop back, they say they have no idea what the issue might be, as it sounds like after being reset to default settings, that the trans is somehow learning this shifting, and are dumbfounded that there are no codes thrown.
Someone on the FB group suggested that if my fuel filter is old/clogged, that can cause the problem. As mentioned in my previous thread, my fuel filter was replaced upon replacement of my CP3 (less than probably 600 miles ago). I do have another new fuel filter I could replace it with but not sure if it'd be worth bothering with if my current filter is that new.
Only other thing I can think of is that I might have one injector that could potentially stand to be replaced, but I'm confused how a crappy injector could cause shifting issues. I did some online searching but haven't read about anyone having a similar problem.
So if anyone can chime in, please do so I can try and point a repair shop in the right direction before anyone decides to just throw parts at it.
Cheers.
I have a 2006 LBZ. Bone stock. Well maintained (allegedly).
Couple weeks back, truck out of nowhere started shifting at a serious delay, as in it would shift at 2100-2300 RPM. It would also downshift really late, and sort of "jab" into gear on downshift. I pulled over, checked the fluid. Bit on the low side but plenty of fluid. It wasn't new but it was still quite red and did not smell burnt. The trans temp was fine, no overheating. No check engine light came on.
On that same day that started happening, I drove home and noticed a puddle of ATF on the ground where my truck had been sitting, and had idled at for a good 10~ minutes.
I didn't have time to fiddle with the truck, so I let it sit for about three weeks. In that time, no more fluid leaked out of the tranny.
I then put about maybe 1/3 of a gallon of ATF in and got it to a reasonable level, and drove the truck to a local well respected transmission shop. They don't specialize in Allisons by any stretch but do deal with them somewhat regularly.
They hook up their pro scantool, absolutely no codes thrown. They find the leak to be a seal on the top bellhousing bolts (or something of that matter), so the trans gets dropped and those get replaced. They then reset the TCM (I believe), and the transmission goes back to shifting fine at the factory default setting. As well, they do a trans service (drain/fill new fluid, new external filter).
I pick up the truck, pay a hefty bill relative to work performed (something I have become all too acquainted with lately). Truck did shift fine. I drive maybe 80 miles (possibly not even), and the truck suddenly goes back to the exact same late shifting problem. No leaks this time. No codes thrown. I call the trans shop back, they say they have no idea what the issue might be, as it sounds like after being reset to default settings, that the trans is somehow learning this shifting, and are dumbfounded that there are no codes thrown.
Someone on the FB group suggested that if my fuel filter is old/clogged, that can cause the problem. As mentioned in my previous thread, my fuel filter was replaced upon replacement of my CP3 (less than probably 600 miles ago). I do have another new fuel filter I could replace it with but not sure if it'd be worth bothering with if my current filter is that new.
Only other thing I can think of is that I might have one injector that could potentially stand to be replaced, but I'm confused how a crappy injector could cause shifting issues. I did some online searching but haven't read about anyone having a similar problem.
So if anyone can chime in, please do so I can try and point a repair shop in the right direction before anyone decides to just throw parts at it.
Cheers.
