writing this for a friend with a 05 3500 2wd. while driving mostly with trailer around 70mph when you lift off the fuel just alittle the truck bangs vilently about 3 or 4 times. so far we changed the cam and crank sensors,brake switch, valve body, changed the tripple disk converter to a different one, fuel filter, had dealer check out fuel supply and said it was fine, put a low fuel pressure light on to see if pressure dropped but didnt. the truck has 90000 miles on it and been doing it for about 40000 miles. we are running out of things to try. any help would be very appriciated. the truck has a super chip on it and we took it off but the problem is still there.
thanks in advance

 

Banging as in metal to metal contact or like an engine back fire?

If metal to metal does the truck have a two piece drive shaft? If so might want to check the carrier bearing.

MikeyB

 

Sounds like my 06,thought the trans was going out,banging like you wld not believe,i know you chg the cam sensor,maybe a poor replacement,mine thru a code, cam sensor.

 

banging as misfire.

 

If there's any programming/chips on it, have you tried removing to see if it still happens? As Alboy said it may have been a poor repair or simply a bad sensor. Try returning it to stock and/or clear any codes it may be throwing and see if that makes a difference. If it's not metal to metal, it's likely not the tranny.

 

we took the progammer off. we will try the cam sensor tomorrow.