At the risk of getting flamed

[OldCracker29]

Yeah, it has the AFM... I was leaning in that direction myself because putting it in third gear does two things...kills AFM and avoids Overdrive so downshifting isn't a problem (if there is a tranny issue) is there an easy way to turn it off without reprogramming?

so a little more detail...from highway speeds braking to a stop it seems to start shuddering at about 25 mph and the shuddering disappears at 15 mph and plays nice all the way to a stop. A deceleration without braking on a level road renders similar results. No shuddering on leaving a stop. No shuddering on acceleration. smooth operation at highway speeds and no vibrations felt up to 80mph. No shuddering beyond that speed either.

I have no idea how to disable it, unless you can do it in the DIC. With what you just described I'd bet it's the AFM. Good luck!

 

[OldCracker29]

Have you figured it out?

 

[Big Ugly]

No, not really. I did get a fluid change on the tranny a few days back...ut seemed to help some. It didn't totally eliminate the issue, just made it less severe. I think I found a way to disable ed afm temporarily so I will check that out this week end.

 

[Big Ugly]

Well, end of the line for this mystery. I invested in a Range Tech device that overrides the AFM coding. Since i have done this, the truck stays in V8 mode, and the shuddering and shaking are a thing of the past. a little on the expensive side, but not near the cost of doing a full blown AFM delete. Thanks for all the feedback.

 

[kennythewelder]

I was going to suggest the range tech, glad you got it.