92 YJ - 4WD jerks loud and disengages?

[mikedashevillejj]

Hope someone can help or had this experience...

92 YJ - When I put it in 4WD, it sometimes jerks really hard with a loud noise. It then disengages 4WD and just spins my back wheels. After a second or two, it will engage back and is fine. This happens at sporadic times when I put it in 4WD. I'm not real educated about my transmission or transfer case.

By the way, 2 wheel drive runs perfect, shifts perfectly.

Thanks for any input or similar experiences.

 

[Andy J.]

Does the noise come from the axle or transfer case?

Edit: I assume x-case after re-reading your post. Isn't that a chain-driven case? Maybe the chain is stretched or something?

 

[mikedashevillejj]

I think it's the t-case that it's coming from. I can't really tell though because it's a big jerk for a second which is alarming.

 

[gearjammer80]

it sounds like the chain might be slipping at first, may have a bad tooth on a gear

 

[sinbad]

Make sure the linkage is adjusted properly to the tcase

 

[GotWood]

I'll bet it is the front vac disconnect. The shift collar is not engaging all of the way.

 

[mikedashevillejj]

mmm, that sounds the easiest to do for a novice mechanic. So just replace the front vacuum disconnect?

 

[GotWood]

There are several reasons it may not work. You could have a vac leak for one. You can make a round or two of electical tape around the male ends of the disco and then re-install the boot if it is leaking there. It could be the switch that is on the transfer case that switches the vac when you put it in 4wd. There are many way's to fix the problem if you know exactly what the problem is. you could remove the disco from the axle, place the collar in the locked position and place zip ties one either side of the axles so that it can't move, then re-install the disco w/o the vac line attached. Make sure to plug the vac line holes. You can also go buy a cable actuated disco for about $200. Or, you can even red-neck engineer it like this one. It is attached to a lawnmower throttle cable ran up to the cab.

 

[mikedashevillejj]

Thanks for the advice. I'll check the vacuum line and connections. Love the redneck cable, much cheaper than $200.