90 GC front end noise Selec-trak

[benjaminbunny]

I believe I have two problems.

1. I can put the Jeep GC into 4WD (full time) while coasting yet while moving. However, it will not come out of 4WD when I move the shift handle back into 2wd (like it use to do when it was newer). I must come to a full stop and put it into reverse to get it out of 4wd. (I have not dared to put it into LO so I don't have any idea if it will shift in or out of LO.)

2. When it is in 2wd it runs smoothly and relatively quietly. When I shift it into 4WD starting about 30 mph, it becomes noisy. More of a low rumble (not a whine or a hum). It tends shake the steering just a little, but not as much as a shimmy when out of alignment. When I get it back into 2wd (see #1) its sound and feel is back to normal.

I have replaced the transfer case replaced. I have not looked at the front differential or any of the various universal or CV joints. I have not check on alignment (but the rumble noise is only while in 4wd).

Any suggestions on where to look to fix these problems.

[fredjacksonsan]

First thing is to make sure your tires are the same brand/size/inflation. Even a small difference in size can cause the 4wd system to bind and cause some of the issues you mentioned.

The owner's manual will tell you that sometimes "untorquing the system twice is required to disengage 4wd" or something similar. I've used the technique of putting the transmission in "2", and adding gas then letting off a couple of times until hearing a clunk, then it's back in 2wd.

My 04 makes a bit of a rumble on the road in full time 4wd also, apparently it's normal.

Shaking in the steering wheel could be that the tires need to be balanced. Even if they were balanced when new, they can need rebalancing after a time. I have 40k on my tires, just had them balanced a couple of months ago...big difference.