Went out on some trails yesterday and noticed a pretty horrible noise out of the front end when in 4wd. It doesn't make the noise when I'm barely giving it gas. I'm assuming the ring and pinion is screwed, but I don't really know much about 4wd's.

Here's the video of the noise. You can really hear it half way and later in the video.



Also, the transfer case is leaking pretty bad, but it's not from the casing, front seal or the oil seal . It seems to be above the fill nut because when the fluid is below the nut, it doesn't leak nearly as bad. Maybe the speed gear 0-ring? I don't know. I just bought this thing a few weeks ago and I'm trying to get all the bugs worked out.

Any advice would be appreciated.

It's a 1996 XJ With the D30 and NP231

Thanks

I also posted this on my local jeep forum.

 

Does it pop out of 4wd

 

The lever? It doesn't as far as I know.

 

Check the fluid in your transfer case? i had extremely bad clunking in my XJ once and it turned out that the chain in the transfer case came off and was just ripping the insides apart. I just changed the transfer case. If you 4x4 actually works, and it's a grinding noise, and only in 4x4.....hmm...maybe something in your front diff? Do you have an auto or 5 speed?

 

Yes, the transfer case is ok as far as fluid goes. It does leak a lot though. No noises when it's in 2wd. Definitely can hear it in the front axle and sounds like it's from the differential. It's an auto.

 

alright then, i'd pop off that front diff cover and inspect the teeth. I've also had the straps that connect the driveshaft to the diff come loose. Just get under there and inspect the driveshaft and make sure nothing is touching it and it's secure. Then pop the cover off with the front end on jack stands and rotate the tires to look in there to see if any of the teeth are busted. That's what i'd do...

 

Been under there a few times and nothing seems out of place. All the U-joints on the jeep are good and tight. The one thing (axle related) that seems wrong is there is a leak on the drivers side.

Ok, went to the garage while writing this and checked the fluid in the diff and snapped a shot of the leak by the hub area.

Well, so far it looks like I need to replace the d/s seal, but might as well do both. Take the diff cover off and flush all the crap out of there and inspect the internals. I'm hoping the noise is just the bearings, but how can I tell? what should I look for when I have it open?

Thanks for your help.

The fluid is horrible. It was close to full, but obviously milky and the magnetic fill plug had sludge on it and very fine metal shavings.

 

Take a pic with the cover off.

 

I will tomorrow, just have to get some fluid and RTV. It's my DD and I'll have to put the cover back on and fill it to get around town until everything I order gets shipped.

After reading some more and watching some videos I checked the axle and looked for in and out play (that's what she said) it seems to be the bearing where the drive shaft attaches even though it isn't leaking from that spot. Who knows...

 

Bump for the morning

 

Ok, took it apart last night and I'm happy to see the ring and pinion looks good. Then again, I have no idea. The axle bearings look intact, but there is bit of play when I pull on the drive shaft at the pinion bearing/yolk/input thing. Not even 1/8". Could that cause the noise under load?
Should I do anything specific to rule anything out? Thanks guys.










Also of note... I got the front wheels off the ground at put the jeep in neutral. Spun the wheels and it made zero noise at all. Forwards, backwards, nothing. Looking more and more like a transfer case issue, huh?

This sucks.

 

Could be chain also. That would be in the t case

 

Chain slap....I hate auto correct

 

Should I pop the cover off and check for slack?

 

Just be careful. I pulled an NP231 apart once and it ended up being a pile of parts.