today i went out riding and decided to go thru a mud hole that i have that goes into the woods. my little girl was riding in my lap so i was taking it easy. my main problem is i need new tires. i did not put it in 4wd prior to going in thought it would just easy right thru. when i did put it in 4wd the light on the dash did not come on but the front drive shaft was turning. while i was in the hole only the back tires were spinning. one of them was off the ground slightly (rear passenger). the rear driver side was spinning. the front tires the best i could tell were not spinning. once i got out i put it back in 4wd low and drove around the yard and it felt like it was in 4wd low. i was in 4wd the entire time i was trying to get out. any suggestions. does it appear that the 4wd is working? i have had the dash pulled in the past and checked all the light bulbs and they appear to be working. i have a 1992 yj 4.0 if that helps out. i am positive that the transfer cases are stock. i dont have any lockers installed.
Sounds like the CAD (central axle disconnect). As Ageless Stranger said this unit is vaccuum operated and can be problematic. Mine is a bit sluggish so I make sure the 4wd is working long before it is needed. Check all your vaccuum lines, even the ones that do not go to the CAD.
oh ok...i guess i will take a look at it again tomorrow....i forgot to mention that just the other day i was driving around the farm and we have a bunch of raised areas and not too steep. i was backing up one of them and once i got to where the rear tires started spinning i put it in 4wd and the light did not come on but it quit spinning and started going up the hill...i was in 4 high....
When your T-case engages and your CAD does not the open diff sends all of the power to the passenger side axle because there is no resistance at all because the axle isnt connected all the way out to the wheel. You could go with a posi lock or build you own to absolutely eliminate this problem. I think there is a write up on this in the sticky above. I would start by checking all of your vaccuum lines. If you find a cracked one replace it.
You could replace the vacuum crap with an aftermarket manual cable setup. Made by Rugged Ridge called cable lock kit part#450900 or if you have a lift done then part#450920. Fits 87-95 YJ/XJ dana 30. I have heard that even a brand new Jeep can have problems with the vac sys. Just not reliable.