I was driving to work today in my 1998 Toyota Tacoma in 4WD on snow covered roads. I had driven for a few miles without a problem when, without any prior warning (that I noticed), the pickup came to a screeching halt. The stopping force clearly came from the front end. I got out of the car and noticed a little bit of a weird smell, but didn’t see anything out of place. I got back in and started it back up (manual transmission so the abrupt stop killed the engine) without problem. I still had the car in 4WD not yet really knowing what had caused the problem and tried to drive. I got nowhere. I took it out of 4WD and again would not budge forward and it still indicated it was in 4WD by the light on the dash. I let off the brake with the clutch in and rolled backward and it immediately went out of 4WD. I was able to drive fine in 2WD without any weird indications. I pulled off on the next suitable street and tried again. Once in 4WD the car would not go forward or backward. I again got out of the car noticing the smell, but this time, much worse. I looked underneath the pickup and noticed nothing appeared out of place with no leaks. The smell was gone almost immediately. I put it back in two wheel drive and drove it back to park it near my house.
I have not had a chance to check the fluid levels yet. The only other similar symptoms I have found on the internet so far are discussing a pinion bearing seizing / breaking off teeth.
The pickup has 230,000 miles and I recently got it from a guy who was the second owner and did a lot of work on it himself. He recently replaced the U-joints, ball joints, inner tie rod, rack bushings and lower strut mounts. We do not live in an area where 4WD would have been required on a regular basis. I use it for a commuter (5 miles city driving) on days when my wife also needs a car and for work around the house.
Any idea what would cause the problem or good ways to troubleshoot to narrow it down? Is it safe to continue to drive it in 2WD or is that going to cause greater problems?