cajflynn - Shutter problem

[Mopar1973Man]

Ok Gang...

I got a phone call from Cajflynn tonight and he's got a shuttering problem with his truck. I'm going to relay this phone call the best I can. So let put our heads together and help him out. He got some internet access on his phone...

SIGNATURE of Cajflynn truck

2001 qdlb, stage 2 f1 injector, 3 disc tc, 4 inch exhaust, arp head studs, ats co-pilot, power puck/smarty, j-hook, lots of gauges, lots of mag-hytec, bhaf, vulcan big line kit, 762K miles

Conditions...

Mild hill climbs at about 63 MPH steady or acceleration the problem (shutter) occurs right at the crest of a hill. Auto Trans temp is <100*F and the rear end about 125*F. Pulling about 800-900*F worth of EGT at 18 PSI of boost. Currently towing about 5K pound trailer.

Now The power puck is traded out with the Quadzilla XPT currently but is shutters the worse with this combo at about 63 MPH. The smarty is in fuel only mode. Trade back to the puck and its not as noticable but still there. But the strange part that the shutter is only notice while towing but empty he's got no shutter. Trans is in good shape...

He's also wondering if the APPS sensor is the cause of this? I got a feeling no... (IMHO)

[Mopar1973Man]

BBT... come gang help him out...

[Wild and Free]

Make sure the wastegate isn't sticking. but that would cause a surge more than shudder, There are just too many things to come up with. No codes I presume?

[guesswho512]

i'm not sure...but you have to work through the obvious. i'm sure it is similiar to the seized brake caliper, you probably don't notice "shutter" when empty. i would tend to think suspension parts but don't forget driveshafts and u joints.

[guesswho512]

does he have a LSD rear end? are these 2 not similar? http://forum.mopar1973man.com/showthread.php?t=1109

Edited January 10, 2010 by guesswho512

[Mopar1973Man]

Make sure the wastegate isn't sticking. but that would cause a surge more than shudder, There are just too many things to come up with. No codes I presume?

No codes present at this time... That what got me scratchin' my head...

[flman]

What is his RPM at 63 MPH? Too much torque for his torque converter? Did he try it with OD off?

Edited January 10, 2010 by flman

[Wild and Free]

I have read that some rigs with a smarty can shuddering in certain conditions. Have him unload the smarty and try it. I was not a fan of smarty in the second gen with any other mods. It was ok on a close to stock or stock rig but I didn't think it stacked well with other mods or electronics from my experience with it, that is why I sold mine.