Originally Posted by
nmineau
the 6.4 will stall at 2400-2600rpm WOT at sea level on the 6 speed on a stock tune. if its only reaching 2000rpm, and the dropping from their, then something is cutting power like crazy, or something else is wrong.
It Should be pretty easy to simulate with a 4wd/full throttle / full brake/ stall speed test to see if you can reach full stall rpm or not (dont do this long in fear of toasting the torque converter fluid.
If you said you strapped the truck to a tree, and were on bare pavement in 4wd, trying to pull it down, and it wouldn't spin in 4 hi, i wouldn't be suppressed cause its so heavy. but in the dirt or especially the snow, you shouldn't need 4 low to break the tires free if its getting full power.
i think something is cutting power like crazy, could be the stability control system, may be the power waggon has some weird torque managment in 4hi that the non power waggons dont