Here's the thing, mine isn't acting up at all...I am just trying to figure how to keep it running for the longest time.
-Alex
*read up about the function of your throttle valve and how to keep the throttle valve cable in adjustment. this is critical for appropriate line pressure.
*keep the TPS voltage dialed in so that it upshifts where it should. research the potentiometer mod
*dont lug it when loaded down, RPMs are the transmissions friend. sure, the motor can glog.glog.glog that load up the hill at 1400rpm but the line pressure in the trans is proportional to RPM. drop it down a gear, let it rev and take your time. be content to go the speed the truck wants, not impatient about going the speed you want.
*lockup switch is a saviour when used correctly.
worst possible scenario for an automatic is dead start up a hill with a loaded trailer. avoid it whenever you can, plan your stops and starts.
ive got a 12v with 47re and 3.54 gears. for loaded down starts like that i take off in manual first gear with the OD disabled. wind the hell out of first gear till it stops accelerating from pump defueling -around 2200 rpm for me- hopefully i make 20-25 mph in 1st. i roll off for an instant, manually shift to second and wait for the shift, then roll back in to keep the RPMs up there so line pressure stays high. i try not to let RPM drop down below 1600 on that upshift. run 2nd up to defuel, lift, clunk to 3rd, roll back in. when the motor is humming good and we've hit 35-40mph i ease back the throttle and press my momentary lockup switch then roll the throttle back in, paying attention for any slippage. when done right, the truck will lunge right up to full boost and sail to 55mph like a nitrous button. let go of the lockup, enable OD, wait for the 4th gear shift, roll in till it gets to RPM and relock the convertor one more time.. i'll crest most hills doing 60-65 with dead start in OD and the tranny is at 150*F. governor springs will really help the 12valves by allowing you to rev the shift even further for increased line pressure.
you kinda have to drive them like a manual IMO. this truck had 2 stock jasper replacements before me pulling toyotas. ive been hauling 8-9k lb trucks and havent seen the trans get over 160.
if you do overheat, the stock valvebody will not oil the convertor in park, it has to be in neutral or gear to circulate fluid. trans gauge is mandatory. sender in the pan or pressure ports is worthless. it has to be in the output line to the cooler for accurate readings of whats coming out of the convertor. a cooler with a thermostatic fan is a saviour for traffic jams.