Allison Upshift Shudder

[P40murf]

My 2003 D/A recently developed a slight shudder when upshifting into 2nd and 3rd, but only under very mild acceleration. Anything more aggressive results in a very smooth shift. The truck is unloaded and not towing. For what it's worth, I have had an Edge w/Attitude for about 8,000 miles set at 1, except for 2 when towing a 13,000 fiver. Total miles is almost 39,000. Any thoughts?

[Buck]

Sounds all to familiar:( I used to have the juice/attitude and experienced the same type of thing. The real annoying thing is when the juice goes off and on in really cold weather:mad: what a PIA. Have you turned the defuel off. It won't hurt your tranny running level 3 or less. That may help. Mess with the low boost fueling settings to.

If that doesn't help sell the juice and get a Kennedy custom efilive tune. I guarantee it will shift perfect, lower egts, and better overall driveability. Oh ya, I have had a solid 2 mpg improvement with Kennedy's "stock tranny" tunes.