Truck stops pulling while going down highway,slow down it starts pulling again

[ALE8-1]

My friend has a 2002 6sp. 3500 4x4 when going down the road at cruising at 55to 75 it will sometimes feel like it has jumped out of gear but it has not,the transfer case is still in gear,the speedo still moves but the truck slows down and then about 35mph the truck will jump and then it will accelerate.

The dealer can't find anything wrong,it only does it every now and then.

Has anyone had this problem,we could use some help.

 

[dmurdock]

Does the check engine light come on?



hmmm... have you checked the fuel pressure?



Give some more info on the truck (transmission, modifications, etc... )



Does the accelerator pedal not respond or does it feel like it's just low on power. .

 

[ALE8-1]

The truck has a edge comp. box and 275inj. KN cone filter 4" exhaust,there are no check engine lights on,fuel pressure is 15 at idle and you can push the pedel back down and the engine revs. up,speedo goes up but truck does not go. I hope this info helps you.

 

[dmurdock]

is it an auto or stick? If the speedo is going up (and you can hear the engine revving), then you are losing power either in the transmission or transfer case... based on what you've said I say the transfer case