i have a '91 pickup 4x4, 3vz, a/t transmission.
the truck moves forward with no problem, just doesnt move when put into reverse. not even when in 4l 4h. or how much throttle you apply.
if i jack up the back end the wheels spin no problem....
any suggestions??

 

I had the same situation as you on my 93 auto 3vz. The tranny on mine went out. I just drove it without reverse for a while till my forwards started to slip. Them I got mine rebuilt. Now it does great.

 

I know precious little about automatics (aside from that they're for lazy people) but I do recall a recent thread here about replacing the solenoids in the tranny itself to correct some issues. I'm gonna go out on a limb here and suggest you search for that thread and maybe look into replacing the solenoids, it could be that the one in charge of "reverse" isn't opening (or closing, or whatever) all the way and that the partial "shift" makes the wheels spin in the air, but remain stationary when they have a load (such as friction with the ground) to deal with.

 

The solenoids control the forward gears only. Does your tranny go forward with the selector in "L"?

 

x2 ... same as ...

Basically, you have massive slipping when in reverse - even the weight of the vehicle is enough to make it slip. My guess is the forward gears are not long for this world either.

First thing to try would be changing the tranny fluid, but at this point, I would say that's life support, not a fix/cure.

 

Couple questions:

Has the A/T TEMP light EVER come on (even once)?

When was the tranny fluid/filter changed last?

Do you have bigger tires? Did you regear?