On my 1990 XJ until I can offord the hub conv. kit i need to fix the 4WD. The TC engages but neither tire spins. The ring and pinon are still in working order. When the 4WD was working you would hear a loud klunk and then the 4WD would disengage itself. From what I understand from checking out the front axle, when the TC is engaged you would still have 3WD, but I was wrong. How dose the front axle work in the XJ.

Unless you have a locker in the front think of your front diff. as water or eletricity. Power is going to follow the path of least resistance. So if the dico stays discoed that axlewill be easier to turn so all the power goes to that axle. You can take your disco off and see why it isn't working. Or take it apart and install washers on the shaft that will keep the axle engaged and you will have use of the 4wd again. Check with naxja.org but it was discussed n there years ago how to do this. Hope this helps.

Check vaccum! Your engine is either not creating enough or you have a leak. The leak is more likely. There are a bunch of little air lines to the t-case, axle disco. and the engine. Check 'em all. I've had the exact same problem when I did a repair and failed to reinstal a vac. check valve that keeps the axles engaged when the engine hits higher RPM (lower vac.)

law.74