Correlation between Jake Brake & Allison Xmtn


New Member
Hello Allison Man..
We have a RV equipped with Cummins 350 and Allison 6 speed 3000 transmission. I have noticed that if I leave Jake Brade switch ON while in slow stop and go traffic, the automatic shift will sometimes "BANG" into a into a lower gear. This will occasionally happen (but not as dramatic) even without the Jake Brake OFF. RV has 43650 miles and has never been driven recklessly. No warnings, temperatures always normal, fluid check on each trip, always normal.
A new problem came up on last 600 mile trip. When climbing relatively small hills (not many large ones on GL or GA I-75) there would be a slight "bang" like a compressor stall or sorts from the rear. Immediately following that there would be a speed decrease, I step on accelerator, RPM increases but no downshift and no power acceleration. Thinking this was a turbo problem I had Cummins do a complete check of turbo & engine. All normal.
Any ideas?
By the way, Jake brake switch ON in slow traffic only if I forgot to turn it off after last time used. I use it selectively.
Dave Johnson