LLY Hard Shifting

rokbrnc · Post by **rokbrnc** » Tue Jul 31, 2007 9:17 am

I just updated my '05 2500HD/LLY, Allison using the Economy/65HP mode. I also changed the configuration to adjust for tire size (325/60/20) and top-end limiter. I took it out for it's first "test run", and while I do notice a definiite power improvement, the transmission shifting is boderline harsh. When pulling away from a dead stop, and applying only moderate throttle, it seems to hold the gear selection to a fairly high RPM, and then will jerk and upshift really hard. Can anything be done to make the transmission shifting operate more smoothly?

Post by **mikel** » Tue Jul 31, 2007 10:30 am

This is due to the Allison tranny having a learn feature.
The tranny will learn the new tune in a day or so, and shifting will improve.

Thanks

rokbrnc · Post by **rokbrnc** » Tue Jul 31, 2007 11:42 am

Great, I was hoping that my be the case. I drove it to work today (approx. 102 miles roundtrip), and I did notice an improvement.

LLY Hard Shifting

LLY Hard Shifting

RE: LLY Hard Shifting