Usually the rear tailgate motor on the 84-95 4-Runners and 80-90 Landcruiser wagons models:LJ/BJ60 & 62 series have the gear on the motor itself strip so a new motor is the solution but they are $250+ at Toyota if they are still available.
What many people have done is gone to a junk yard an bought a Celica,Supra,Camry or Mazda 323 or 626 power window door motors as they are in excellent shape and have cut & crimpt the old harness on it and works like new,you have to realize that 4-Runner,pickup & Landcruiser parts are in high demand so they are difficult to source and cost alot.
4-Runner rear tailgate window motor:
80’s Celica/Supra
87-91 Camry (left or back door), passenger side door power window motor out of Camry
Mazda 323 or 626’s passenger or driver’s side window motor two of the holes line up while the 3rd needs filing.
Sidney
Repair tv's,vcr's,home/car audio out of my home
E-mail:sidneybek(at)yahoo.com
Dartmouth,Nova Scotia
Canada
1985 Toyota 4-Runner,22R-E,W56,RN60LV-MSEK,rusted rear step/towing chrome bumper with 241 000 KM