that the PO swapped a 350 into, and left two bearings out of a tranny rebuild "so it would shift hard" but all it does is shift hard into reverse.
IDK exactly what that all means, but I think it might possibly be relevant to your issue as described. But before you even bother reading the rest of this post, I have to ask a couple of questions;
First, I assume the "350" that was swapped into the truck refers to the motor and not a TH350 transmission - right? And that the engine came from a different model/year truck?
Next assumption - the transmission is a 700R4 with a TCC (torque converter clutch). Is the TCC wired up and connected to a power source?
If the truck has a TCC type transmission and it is wired to a power source (and the currently installed engine/factory ECM are not compatible), read on. If any of those things are not true... you can skip the rest of this. On the other hand, if those assumptions are correct, you might want to look into the possibility that your TCC is not unlocking. When that occurs, it is essentially the same as not disengaging the clutch on a manual transmission while the truck is stationary - well, not exactly that bad - because there is some slip even with an overdrive equipped transmission.
Recently, the truck has been stalling out when put into gear with any load on it (trying to R up hill or trying to D up hill).
If I shift the transfer case into N or 4L, it won't die, so I tried crawling up a hill in 4L, then shifting back into 2L and driving back down the hill.
You don't mention what happens if the transfer case is shifted to 4H - does doing that also allow the engine to idle properly?
All is fine until I come to a stop sign, then the poor idle returns and it dies. When it is my turn to proceed through the intersection, it creeps, missing and sputtering, and if I give it any fuel it dies. Sometimes I can accelerate just right to bring it out of the rough idle, and it won't die.
I am guessing that the above statement is meant to describe how the truck acts when coming off cruising speed (and to a complete stop) only when operating in 2WD? But, how about if the transfer case is in either of the 4WD positions? If the TC is in 4WD, is the engine able to maintain a proper idle while the truck is stationary - and then, accelerate normally after coming off idle?
So I put it in R and it died, as there was a slight downgrade on the lot so there was a load on the truck. After restarting and dying about 20 times I put it in 4L and was able to get to a flat surface, yet it didn't stay running in D in 2L until I was going downhill.
Shifting the transmission into neutral always seems to eliminate the idle problem - correct?
from searching through the internet, I gather it may be a Torque Converter issue?
I think you're on the right track. But, since shifting the transfer case to a 4WD position seems to alleviate the problem, it is a possibility that the stalling is due to a TCC that is not releasing as designed (as opposed to a torque converter issue).
The engagement of the TCC is normally controlled by the ECM. The ECM monitors the following sensors to determine whether the TCC should be energized:
1. VSS (vehicle speed sensor) – road speed must be above 30 MPH
2. Engine coolant temperature – must be above 149 F
3. TPS (throttle position sensor) – vehicle must be at a steady speed (not rapidly accelerating or decelerating.
4. The brake switch – must be closed (i.e. the brakes are not being applied)
5. The 4WD relay. If the truck is equipped with 4WD - and the transfer case must be in either the N or 2WD position – to enable the TCC.
So, say the PO just dropped in any old engine - one that did not have the right sensors for the ECM (he modified the transmission), but he still wanted to have overdrive capability... it would be very easy to just hot wire the TCC solenoid straight to the brake switch. That would leave only the 4WD relay to disable the TCC.
Anyway, for this scenario to occur, the brake switch would have to be bad - and not opening when the brake pedal is applied. But other than that, if the ECM is not wired to the correct - engine mounted – sensors, the only other component that would disable the TCC would be the 4WD relay. It shouldn’t apply power to the TCC without the above permissives being met. But given the fact that the TCC solenoid might simply be hot wired around the ECM, the only remaining controls would be the 4WD relay and the brake safety switch.
Simple enough to diagnose – disconnect one of the wires from the brake switch. The hot wire to the brake switch is brown or brown/white. Pull it and see if the situation improves - without having to put the transfer case in 4WD.
