1990 front axle noise????

OK,
Is it me or is there something to look at?

I have a 90 with AW4, comand trac, with a dis-connect axle.
So, when I put it in 4wd, I think the front axle is doing some strange things.
I know it is 4wd, because I can feel the wheel hop IF I turn the wheel sharp. But some times, I feel like I am going over a large crack in the pavement. Almost like the axle is trying to connect or possible dis-connect.

Talked to the jeep dealer, and they say that the system on the 90 needs no special attention, as it get's oil from the axle, which I have changed. I did replace the u joints at the end of the axle, so I think those should be fine.

Any thoughts before I start to tear it apart? Really not interested in going out in the cold with out knowing what to look for.........

Thanks in advance.........Your thoughts?????????

Bob:doh:

check for play in the front d/s with the wheels off the ground in 4wd. My transfer case chain was stetched and skipped under load or bind causing the same noise/ feeling yours was especially while under load

any chance your gearing in the front is different than the back?

The command trac is the NP231 which is a part time only 4wheel drive transfer case.
You should never put it in 4X4 on the street. when you are in 4x4 there is no way for the transfer case to compensate for the difference in speed when you turn the vehicle on the street, causing the drive train to bind and eventually relieving its self by popping or possible drive train damage.
Its should only be engaged off road in loose traction conditions.
The other popular Cherokee transfer case is the NP242 and it has a internal viscous coupling when used in full time 4X4 that allows it to slip therefore compensating for the difference in wheel speed between the front and rear during a turn.
Hope that helps, theres probably not anything wrong at all.
Coop

Maybe you should take it out in some loose gravel or light mud and see if it still pops or not. If it continues then look into it further.

I recently had my t/case apart and did not see any viscous coupling. 89 aw4 with np242

check your linkage...mine did the same thing and i found out when i reinstalled the trans/transfer case i didnt adjust the linkage right..the handle was in 2wd but the actual t/c was in 4HI...took me about 5 min to fix it

bcmaxx said:

I recently had my t/case apart and did not see any viscous coupling. 89 aw4 with np242

Click to expand...

Your right that was the 249.
I think it uses something similar to a limited slip instead.

Thanks for the quick response.
I should of mention, that it is only in 4wd on snow covered roads. We are finally getting some snow here! I do have a grand cherokee with select trac, which I would like to have on this XJ!! So I do know that this one should not be on hard dry pavement in 4wd.

This one is stock as far as I know. Of the 6 Jeeps I have had, this is the first with a dis-connect axle. I don't remember the noise last year, but I did the U-joints over the summer months.

Thanks for all the input.........

Bob:sad1: