93 4x4 problem

Yet another 4x4 no work issue. I do not work on my own truck so must rely on my mechanic. It has been in twice to fix the 4x4 which is not engaging when the button on dash is pushed. "Motor" was supposedly rebuilt (although not sure what this means) - worked for a day. Return trip - it was "packed with grease" but what I don't know - worked for 5 days. I engaged and disengaged it before commute to and from office. Fifth day it worked in morning but not in the evening. The weather was below freezing the days it worked and above freezing (40) and raining the day it quit. Any suggestions for me to give guidance to my mechanic who I really respect and has usually kept me in business but must be missing something on this one. I live in the North East and now communite a distance that I really do need consistent 4X4 performance. Thanks

I've had to rebuild mine a couple of times on my 92. The last time, I tested the "rebuilt" assemble on my bench with a power supply. This power supply went into current limit when the motor drew over 4.5 amps. The problem is that the oil dries out in the bronze bearings. It took pulling it apart 2 times and working oil into the bearings before it would work. After that, the motor drew less than one amp. I suggest that the switch gear be removed and the motor be allowed to run in on the bench for 15 minutes. An easy test is to put a brake light in series with the power to the motor when bench testing. If the motor will run with the lamp in series, it will work in the vehicle. Motor should easily run both directions with only 6V @ 3/4 amp. Transmision fluid is a good light oil for this purpose.

I have a Hub Problem and would like to have photos of the parts in a Auto Hub. Could not find any in the WEB but thought after a lot of search I would find some sort of Photo in the 4X4 pages some where. I just need to know if I have trashed these things or just loaded them up on grease and need to clean them better again.