Lately when I've been out offroading and get into slippery ground, only my rear tire slips while in 4WD. It's a 93 pickup with manual locking hubs, they used to work fine.
I've looked below and the driveshaft to the front is spinning while driving. So i am thinking a hub(s) are not engaging or something. I don't have too much experience with the hubs, so any good pointers to what i should look for or what typically goes out in them? Thanks

 

It's pretty easy to troubleshoot where the problem is. Park it on a level spot, lock in the hubs, and engage the transfer case in 4wd. Then jack up both front wheels. Turn one of the wheels by hand and watch what happens to the other one. It should spin in the opposite direction. If it doesn't, you've got a hub problem. To figure out which hub isn't locking, watch the front axles as you spin the wheels. The axle that doesn't turn with its wheel is the one with the bad hub. Assuming you don't have a locking differential, it only takes one bad hub to render your front drive useless.

It's also possible you have a problem with the Automatic Differential Disconnect (ADD). If the manual hubs were added as an aftermarket item, you probably have ADD. It's a vacuum operated internal disconnect on one side of the differential. If it fails, you'll be able to spin both wheels independently in the above test even if the hubs are properly locked.

Perform the test and let us know what you observe.

 

Hey thanks for the advice, i checked and sure enough my passenger side hub is not engaging. The axle does not spin when i spin the tire. The driver side works fine. What should i look into fixing or replacing?

 

You likely either have a broken spring or poor lubrication such that the collar doesn't slide into lock any more.

Check out this link. Everything you wanted to know and more about rebuilding your manual hubs. It's not too complicated once you get into it.
https://www.yotatech.com/forums/f116...ild-up-158644/

You don't have to remove the wheels or jack up the vehicle to repair the hub, unless you want to repack the wheel bearings at the same time (probably not a bad idea.) To remove the hub, first put it in the "free" position. That keeps the springs and other pieces from flying out when you take it apart. Next remove the 6 small cap screws holding the face plate on and pull that part out. From there remove the nuts and cone washers that hold the hub to the wheel. You'll also need to remove the center "gold" bolt (which you can see after you remove the face plate) before the hub will come off.

The hardest part is getting the cone washers off of the 6 studs that hold the hub to the wheel. There are various strategies, but generally loosening the nut (but don't take it all the way off, so the cone washer doesn't fly off and get lost) and then smacking the nut/stud with a hammer and/or the cone washer with a brass punch will eventually get the job done.

Once you get it off the wheel, follow the instructions in the link above to rebuild it.

 

Thanks for the replies. I was gone all weekend, but today i took it all apart ans sure enough, grease was all dry and nasy and everything was seized together. So i cleaned everything up and greased it all. Now it seems to work perfect, problem solved. Thanks again!

 

Great! Thanks for letting us know you got it working! Glad we could be of help!

 

i recently bought a 92 4runner that the 4wd wasnt working so i got some new parts that were missing for instant new cv axles, new front driveshaft and i checked the sensors that all data pointed out to but no luck