Manual 4x4 engagement system

[dimwalle88]

Having issues right now with my front wheels locking up (its an 87 cherokee 4.0 automatic), my buddy thinks its the vaccum disconnect system failing. Before i do this, does anyone know if there is a way to check and see if thats the issue? Any input would help.

[Mudderoy]

Having issues right now with my front wheels locking up (its an 87 cherokee 4.0 automatic), my buddy thinks its the vaccum disconnect system failing. Before i do this, does anyone know if there is a way to check and see if thats the issue? Any input would help.

I'm interested in seeing the responses to this but my understand is that if it failed, it would either be engaged or not. If your transfer case in in 2wd it really shouldn't make any difference.

When you say "locking up" do you mean it won't move forward, backward, or chrips and jumps when making turns?

[4.3LXJ]

If the vacuum disco fails, it won't engage. If the wheels are locking up there are other issues. Better pull the diff cover and have a peek

[Mudderoy]

If the vacuum disco fails, it won't engage. If the wheels are locking up there are other issues. Better pull the diff cover and have a peek

Hmmm sounds like what happened to Wayne before his Jeep tried to kill him.

[4.3LXJ]

Yup, threw the pin. This could be the same

[dimwalle88]

It drives straight fine but when I am turning it will lock up the passanger front tire. I lifted the front axle on jack stands then rocked the tire back and forth freeing up the tire then it works fine until i try to do a figure 8 in 4wd. When I get some free time this weekend i will pull the diff cover and look at it.

[4.3LXJ]

OK, you said wheels right? Is it just the left wheel?

[dimwalle88]

Yep, just the left wheel. My bad about the plural.

[4.3LXJ]

You have to be specific on this. It makes a difference. Forget the diff cover. First suspect is the front wheel bearing, second is the axle U joint, or both

[dimwalle88]

I will be more specific next time, thanks. Is there way to check them (in a sense of how you would check ball joints and tie rods?) or is it more hit or miss?

[4.3LXJ]

Jack it up and spin the wheel. If it is noisey, sounds rough or a dry metal on metal sound it is probably the wheel bearing. You will have to pull the axle shaft to check the u joint

[dimwalle88]

Thanks I appreciate it and will jack it up in the morningto see if i hear anything. Pulling the axle may take another weekend and the help of some friends.

[dimwalle88]

Update for you guys, It was the passenger front brake locking up for some reason. Took it apart/cleaned it up/bled the lines and everything just sort of worked out :smiley-gen165:. Was able to take it out for a nice long weekend of wheeling. Appreciate the help guys, everything yall spoke of were great ideas.