do you mean you tightened your slipper assembly /spur gear?
is the truck idling? if so is it a slow idle? or fast idle?
if fast idle, thats the problem and oyu need to reduce the idle either by tuning, or by trim.
if slow/no idle, there is an issue in your clutch, either shoes, springs, bearings, or bell itself.
going to need to tear into it to figure it out.
take pics along the way, it is actually really simple to do.
should be able to pop off the spur gear, undo the E clip at the end of the shaft, then pull off the Clutchbell.
Clutchbell example: