transmission on the truck is acting like it does not have fluid. It is full and change last year. not burnt either. 1989 fj 62 has 142,000 miles on it. The screen was cleaned at the same time the fluid was.
I've been there with the rig moving 3mph at 3000 rpm.... Euclid knows. But you could smell the burnt on my dipstick. Good luck with it. Go with the tranny that GT was talking about, don't let any ol jackass rebuild your A440F, you probably won't be happy with the results..
Not a bad place to start. Email Rodney and he will send you directions on how to flow test the transmission while you are changing the fluid.
Double check the adjustment of the kickdown cable for good measure.
Here's another test... put the truck in 4 low. I'll bet you will be able to move just fine. The increased preassure at higher RPM's (because of lower gearing) will overcome the clutch pack slipage that is happening.
When you get the new transmission go ahead and get the cool valve body with 3rd and 4th lockup. You will love it. Trany temp guage is a must. Might as well install an auxillary trans oil cooler at the same time. Since everything is out, you should also look into a McNamara gear.
It sounds like its time for a rebuild, but id check your tv cable too. I got mine rebuilt about a year ago, and i think that it might have just been the tv cable being messed up. It would stick open or closed and not allow the tranny to shift (either too much pressure to shift or not enough). Sounds like you have mad nasty slippage but it might help.