4x4

[dnewman]

Big snowstrom pushed the 4 w button light comes on but 4 wheel does not ingage. I hear a faint click at the transfer box but no engagement. There is no noise comming from the hubs and everything worked last time I used 4 wheel acouple of years ago. Any advice on where I start looking for the problem? PS:it does have automatic hubs!

[Opera House]

So what year is it. 99.9% of the time it is the shift motor assembly. These get a bad electrical contact in the shift plate and the bearings dry out in the motor. If you are handy, you can clean and lube the motor in less than 2 hours (I've done a couple of them) or you can buy an new one for about $250. Just need a little dusting and cleaning. Do you work on your own vehicle?

[dnewman]

Originally Posted by Opera House

So what year is it. 99.9% of the time it is the shift motor assembly. These get a bad electrical contact in the shift plate and the bearings dry out in the motor. If you are handy, you can clean and lube the motor in less than 2 hours (I've done a couple of them) or you can buy an new one for about $250. Just need a little dusting and cleaning. Do you work on your own vehicle?

Its a 1992. I have done a fair amount of work on older cars and I would like to give this a shot. Is there anything that needs to be marked for alignment or do I unplug then remove the motor take it to the bench disassemble, clean and lube?

[Opera House]

You can remove the motor assembly and the shaft is sealed to the transfer case. The 2WD position is stamped on the transfer case and it seems to lock somewhat (wouldn't trust it) in that position. To remove the motor is three bolts pluss one on the motor. Brown wire is generally cut and speed sensors just pulled out. Cut a notch on the switch cover to the bofy for correct position. Mark case with 2WD shaft position for when you put it back. Getting brushes back together is the usual story if you have sone motors.

I just tested my shift motor and it drew over 4A tripping the circuit protector on my bench power supply after a quick rebuild. Took it apart again, cleaned the brushes, commutator, and lubed it a little. With the encoder gear removed, it now drew 1 1/2 amp. It seemed to strain and after several times of my reversing polarity/direction, current climbed up to about 3A. After filling the worm gear area with tranny, working it further, and polishing the shaft, current is now about 0.6 amps. This is now the third time I've worked on this. The other times lasting about 2-3 years. Other times I just slapped it back together. I definitely think you need to work some light oil into these bearings by running it a while off the car. The encoder gear must be removed because it has a stop on it and won't do a full rotation. So many of these may stop working because they exceed an electronic current limit. A brake light in series with the motor is a good test to see if the motor is free enough. Motor easily works with about 6V drop on the bulb.

Here is a thread that gives other details.

http://www.glue.umd.edu/~singletn/web/pages/tcase.html
_