Recently I had to part with my 76 fj40 because of my purchase of a 96 fj80 in great condition. The guy I sold it to later emails me saying the 4wheel drive will not engage. Never did I have any problems with this and would never have sold it to anyone in that condition unless they were aware of the problem. Any ideas from anyone what might be the issue? He tells me that the shifter goes into the high/lo but the rear wheels do not engage when trying to pull a trailer.