I was towing a 27ft enclosed snowmobile trailer down the highway with my juice box on level 2 and my transmission shifted down and stuck in 4th gear. My service engine soon light came on. I shut off the truck and started it up and it was still stuck in 4th gear. I drove the truck for 30 miles stuck in 4th gear. I shut off the truck for 10 minutes , restarted and drove off with service engine soon light on. The truck shifted normal and went into high gear. The service engine light went off in about 100 miles and hasnt came back on. This is the 2nd time this has happened. first time I did not even have a trailer hooked up?

Anyone experience this?

Closest thing I've had was while going down hill in tow haul mode, tranny downshifted to fourth because I was applying the brakes, Allison tranny braking kicked in. But I had to really step on the gas for it to shift back to 5th, I mean the RPM was near 3000 before it would shift.

Anyone experience this?

possible trans limp .......u need to check codes , look for a po700 code first, then go from their. (basicly the tcm is requesting the mill lite for a trans malfunction !!!!!)

It probably slipped in 5th. It probably has a code stored for an undefined gear ratio. I have done the same thing a few times when using propane while towing.

Ease up on the peddle or ya might as well call MikeL for the cure......

My truck has done that before and all i have done to it is a diablo predator programmer with 4" stight pipe and i was wondering what that was myself, I just put the tranny in neutral and then back in drive and the problem fixed itself. It has only happened 4 or 5 times and everytime it has happened the progammer has been set on 120hp. Also if i drive around with the programmer turned all the way up, and i "get in it" a lot, it's like my truck doesn't have enough fuel being pumped to the engine. It like starts cutting out and slowly the rpm's drop when your foot is on the throttle. But if i turn it down it quits. Do i need a bigger transfer pump or lift pump? Whatever u want to call it.

How much weight are you hauling? If it's a steel trailer, I don't think i'd be running on setting 2.

I had an 02 with the edge on 125 hp stacked with a bullydog powerpup downloader 90hp, this thing hauled a$$! I never had any trouble with the tranny? This 05 has been doing this with juice on level2 @ highway cruise speeds?

How much horse power and torque with these allison trannys hold does anyone know. I've been conserned as to what thier limits were.

I was towing a 27ft enclosed snowmobile trailer down the highway with my juice box on level 2 and my transmission shifted down and stuck in 4th gear. My service engine soon light came on. I shut off the truck and started it up and it was still stuck in 4th gear. I drove the truck for 30 miles stuck in 4th gear. I shut off the truck for 10 minutes , restarted and drove off with service engine soon light on. The truck shifted normal and went into high gear. The service engine light went off in about 100 miles and hasnt came back on. This is the 2nd time this has happened. first time I did not even have a trailer hooked up?

Just had the same thing happen to me last night when I went to pass a car on the highway. Got half way past and then it jumped down into 4th and stuck there just like yours. Got the engine light but it went off this morning. I figured I had my foot too far in it and it probably slipped in 5th.

It's my understanding that the STOCK transmission will handle somewhere from 70-90 HP over stock before slippage begins. Build the tranny FIRST and life is good. :ro)

i have experienced the same thing as you described...limp tranny i think was it. my 03 dmax was way more powerful i think, than my 05....i think it is all the emissions crap and i think GM also did a different program in these trucks.am wanting to find an "easy to read and instructions" to get that EGR out ....i wanna see if that makes driving my catless straight piper easier and smoother.

i have experienced the same thing as you described...limp tranny i think was it. my 03 dmax was way more powerful i think, than my 05....i think it is all the emissions crap and i think GM also did a different program in these trucks.am wanting to find an "easy to read and instructions" to get that EGR out ....i wanna see if that makes driving my catless straight piper easier and smoother.

So your 03 with 300hp and 520tq was way more powerful than your 05 that has at least 310hp and 605tq? :rolleyes:

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