AeroSynch

1999 XJ
D30 - AW4 - NP242 - 8.25

My XJ is making a weird noise in the front area around my feet when I drive over 15 MPH and progressively gets louder the faster I go. I think it is the D30 that is messed up but need suggestions.

This is what I have done so far to test the noise:

-Changed D30 fluid
-Removed front drive shaft
-Changed NP242 fluid

After doing all these one by one (different days) and driving it after, it still makes the noise.

I am hoping that I don't have to replace the entire front axle, but it is looking like so. Any ideas?

CartsXJ

Reach under and grab your front driveshaft and see if any of the u-joints or CV centering ball is worn out.

no rdplz

Get underneath and grab the pinion on the front axle. Try moving it around. If it has some decent play in it you'll want to check your pinion bearings. Your driveshaft u-joints could also be going and contributing, so even though you've already pulled it, check those over.

AeroSynch

Nope they are all good. If they were wouldn't the noise have stopped when I removed the front drive shaft?

AeroSynch

I believe it does have play front to back, and now that you mention it, when I shift into 4WD the noise calms down a bit before getting worse.

Also, when I am driving on a bumpy road, every time the axle moves up the noise seems to stop? So this is leading me to believe that it is the pinion bearing like you say?

no rdplz

very good possibility then. Check them soon as they can tear up the housing if you let them go for too long. Then you will need a new axle.

AeroSynch

I have to remove the carrier and reset the backlash to do this too right?

austinjoe13

My guess would be a bearing. Grab the pinion yoke and feel if there is excessive play in it. If it feels good then jack up the front driver tire and grab it on the top and bottom and try to rock it. If there is any play, look at the steering knuckle while you do it to make sure it's not the ball joints. If the knuckle doesn't move but the brake rotor and hub does then it's your wheel bearing. I believe they're about $30. Might as well check the other side too. I thought my driver brake rotor was grinding but it was really the passenger side.
If these all feel good then it's in your diff and you'll probably need a rebuild kit.

austinjoe13

Yes

AeroSynch

Yea it most definitely is the pinion bearing or any of the inner bearings since the wheel hubs are new along with u-joints.

no rdplz

best bet is to buy the master rebuild kit and just replace the bearings and seals all at once.

austinjoe13

^x2

AeroSynch

I would if I was keeping it, but I am not. I just wanted to know what the fix would be to put on the ad. I am looking into a WJ as I don't off road as much now and drive on the highway a lot to and from college. Thanks guys!

CartsXJ

Sorry, missed the removal of the front d/s, lol!

Pretty much everybody else has named all the possibilities, so........get after it, haha!!!