I just got done converting my hubs to manual, even though only one was bad. I found all the parts I needed to fix my bad hub from a guy here on the board, Kris (KrisGuilbeaux [kguilbeaux@cox-internet.com]).
The good news is that they are real easy to test. With your Ex in 2wd, crawl underneath with a pair of gloves, a long screwdriver, and a flashlight. Turn the front driveshaft and watch the axle shafts coming out of the front differential. You should see the axleshafts turn a liitle bit then feel a "click" as the hub clicks itself locked and then the shat won't turn anymore (unless you've got the tire off the ground in which case the wheel sould turn). If one side clicks and the shaft stops turning but the other side still turns then that's the side with a broken hub. Now jam the screwdriver in the u-joint of the one that is broken and see if the good hub holds so that you cannot turn the driveshaft any more. Of course, if you've put a locker in the front diff then you can't check them this way. If you have a front limited slip then you may be able to get enough muscle on the driveshaft to get the clutches inside the diff to slip, thus acting like an open differential.
Now that you know if your hubs are good, check your t-fer case. While under the vehicle, have someone switch the ignition to the run position (do not start it up). After all the electric noises stop, have them push the 4x4 button while you have your bare hand on the t-fer case shift motor (looks like a power window motor). You should feel it whir and hear it hum as it activates. Now turn the front driveshaft again. If it is in 4x4 then it will only turn a little then stop. If it still turns like before then the case is still in 2wd. Ask your helper if the 4x4 light is on - it shouldn't be if the motor didn't move. Try thumping the motor a couple of time with something while your helper pushes the button and see if anything happens. If you take the motor off, you can get a pair of pliers or vice grips on the shaft coming out of the transfer case and rotate it ccw (I think) to manually put it in 4wd. Also, with the shift motor out you can have your helper push the button again and see if the wheel inside turns. The contacts that lights the dash LED's, and tells the controller what position the wheel is in are located on this wheel and is what most often gets dirty and causes the t-fer case not to be engaged.
Sorry for the long post, hope it helps.
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An even better way would be to leave the X on the ground in 2H.. Crawl under and rotate the front drive shaft (either direction). You should see it rotate the front axle shafts going to each wheel. After a few revolutions the hubs should lock and you will not be able to rotate the shaft anymore. If you can still rotate the shaft after 10 revolutions it indicates one or both hubs are bad (the bad hub will be the one whose axle shaft is still moving). You can confirm this by rotating each axle shaft separately. If the shaft continues to move the hub is bad, it it stops the hub correctly locked.
DeRocha
