Odd Transfer Case sound

Sounds like a half a handful of BB's in my hubcaps. It's a light clinking and clattering sound. But it's coming from inside my transfer case. It starts up at about 3-4 mph and gets faster as the mph picks up in both forward and reverse, in 2wd and 4wd.

There is no other symptom besides the sound. No clunking, clanking, or roaring, like something you'd expect with a serious problem. And the vehicle drives and shifts normally just like it always has. If I hadn't noticed the slight noise (in a fast food drive thru lane with the windows down), I would never have known there was a problem. The sound started about 300 miles into a 600 mile Interstate trip, as far as I know, and didn't get any worse or even sound any different after the 600 mile return trip a few days later.

I took it to a Jeep Dealer shop at my destination but they apparently couldn't diagnose the sound either. Just offered to tear it down for $270 and THEN give me an estimate to fix it and put it back together once they find the problem. But that would take days to order parts etc. and I needed to get back home. So I drove it 600 miles back at

65-70mph with no problems whatsoever.

It's a 1999 Cherokee XJ with 167,000 mostly ON road miles (very little

4wd use). It's a one owner (me), always well maintained, and fresh out of the shop for some pre-trip work that was totally unrelated to the drive train (a/c work, water pump, etc like that).

Now that I'm home, I want to fix it. But I'd like to use a different shop than the one I've been using. Seems like every time I take it there, I end up with a problem that I didn't have before I took it in and I'm beginning to wonder if that may not be a coincidence.

Anybody have any ideas??

Thanks in advance,

Rick HeBeJeepN '99 XJ Sport, Selec-Trac, Trac-Lok

Reply to
HeBeJeepN
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Drain and refill the case, check for metal. Could be a loose chain. Let it run long enough it can jump or simply eat through the case.

Sure it's coming from the xfr case? It's hard to tell where a sound is coming from without using "chassis ears"

Rattles can also come from loose catalytic conveter covers or from a cracked exhaust pipe.

One time I had an annoying bb like noise from the back of the ZJ.... turned out to be a metal snap on my winter jacket! :]

Reply to
DougW

If it's REALLY inside the xfer case, noise related to speed, and 167k miles, your chain is badly worn. The XJ spins the front driveshaft all the time so the chain moves all the time. The $270 is expected dealer price to remove the xfer case and move it to the bench.

New chain is around $100 plus gaskets, most of the cost is labor. My last chain ran about $150 total for parts, around 8 hours of my labor. (OK, I'm not as fast as I used to be!!) Flat rate book will be around the same number.

I like Doug's idea of drain and refill with a careful check of the drain. A loose chain usually starts milling out the side of the aluminum case, the oil should have a good collection of aluminum chips.

This is not something you can ignore for too long. Once it gets stretched enough to mill the case, it is stretched enough to jump a tooth under load. THAT would cause serious damage. 2wd on the highway should not be a problem, 4wd in the rocks would be pretty iffy.

Reply to
RoyJ

Yep, it's coming from inside the xfr case. The Tech didn't hear anything at all at first so I had to leave my comfy chair in the waiting area to drive past him in the parking lot. He heard it then though and put it on a different lift so that he could spin each wheel and listen. I don't know what kind of ears he used but he finally agreed with me that the sound was definitely coming from the xfr case.

Draining and checking for metal is a good idea. I'll do that next. I don't know if the $96 diagnosis fee included that or not but it should have. Probably not though. There's nothing said about it in the report.

Thanks,

Rick HeBeJeepN '99 XJ Sport, Selec-Trac, Trac-Lok

Reply to
HeBeJeepN

That all makes sense except this noise started suddenly. It was not there at all when I left home. After 13 years and 167,000 miles, I know my Jeep noises pretty well. Then, after 300 miles, it was there. And it didn't get any worse or any different at all over the next 900 miles. Just sounds like something inside came loose and is now half attached and rattling in there or laying across something that is spinning.

I think of a wearing noise as something that starts gradually and continues to get worse with time. And btw, this doesn't sound like metal grinding between gears. I guess that's possible though. It's hard to describe what it sounds like.

The reason I was willing to spend $96 for a diagnosis at a dealer 600 miles away from home was because I thought they would probably recognize the sound if it's common. And seems like a worn chain would be fairly common and recognizable. But apparently the tech didn't have a clue what was causing the noise. Or if he did, they didn't tell me. But they did tell me I could probably make it home (600 miles) if I just didn't push it hard.

And now I'm also wondering if anything nefarious might have been done to my xfr case by my home shop. And if so, what might be easy to break and then, later, easy to fix (for large $$). I know this seems paranoid and accusatory but shops have actually been known to screw up something while they're fixing something else, yanno? lol!. And the "coincidences" are beginning to pile up with the local shop I've been using.

Anyhow, I wanted to post here because over the years this group has been a wealth of information. Actually helped me decide on buying my Jeep in the first place, back in '99.

I'll drain and check for metal.

Thanks guys :-)

Rick

HeBeJeepN '99 XJ Sport, Selec-Trac, Trac-Lok

Reply to
HeBeJeepN

I don't know what the rear drive shaft and pinion are like on an XJ, but I swapped a ford 9" into the rear of my CJ about 4 years ago, last month I had a noise just like you are explaining, turned out to be the pinion bear cover, or whatever you call it, round 4" or so disk that is behind yoke, although this may not be anything like yours, it is definitely worth a check, sounded just like a miniature symbol clanging around.

That all makes sense except this noise started suddenly. It was not there at all when I left home. After 13 years and 167,000 miles, I know my Jeep noises pretty well. Then, after 300 miles, it was there. And it didn't get any worse or any different at all over the next 900 miles. Just sounds like something inside came loose and is now half attached and rattling in there or laying across something that is spinning.

I think of a wearing noise as something that starts gradually and continues to get worse with time. And btw, this doesn't sound like metal grinding between gears. I guess that's possible though. It's hard to describe what it sounds like.

The reason I was willing to spend $96 for a diagnosis at a dealer 600 miles away from home was because I thought they would probably recognize the sound if it's common. And seems like a worn chain would be fairly common and recognizable. But apparently the tech didn't have a clue what was causing the noise. Or if he did, they didn't tell me. But they did tell me I could probably make it home (600 miles) if I just didn't push it hard.

And now I'm also wondering if anything nefarious might have been done to my xfr case by my home shop. And if so, what might be easy to break and then, later, easy to fix (for large $$). I know this seems paranoid and accusatory but shops have actually been known to screw up something while they're fixing something else, yanno? lol!. And the "coincidences" are beginning to pile up with the local shop I've been using.

Anyhow, I wanted to post here because over the years this group has been a wealth of information. Actually helped me decide on buying my Jeep in the first place, back in '99.

I'll drain and check for metal.

Thanks guys :-)

Rick

HeBeJeepN '99 XJ Sport, Selec-Trac, Trac-Lok

Reply to
Greg

I think the Wrangler & Cherokee drive trains use very similar (if not identical) components but if I understand you correctly, your noise was coming from your rear differential and mine is coming from my transfer case. Not sure if my xfr case has any covers, or whatever, that might be loose and rattling but I'll check and hope I have a noisy extrenal part rather than an internal one. Thanks for the come back. Rick HeBeJeepN '99 XJ Sport, Selec-Trac, Trac-Lok

Reply to
HeBeJeepN

Driving down the road with no doors on and daughter in pass seat trying to find the noise, she said it was coming from her side, I said my side, she said front I said rear, so it is worth a poke at anything on drivetrain that could move.

I think the Wrangler & Cherokee drive trains use very similar (if not identical) components but if I understand you correctly, your noise was coming from your rear differential and mine is coming from my transfer case. Not sure if my xfr case has any covers, or whatever, that might be loose and rattling but I'll check and hope I have a noisy extrenal part rather than an internal one. Thanks for the come back. Rick HeBeJeepN '99 XJ Sport, Selec-Trac, Trac-Lok

Reply to
Greg

On Fri, 3 Aug 2012 06:51:31 -0700, "Greg"

Yeah, mine sounded like the left rear wheel/brake at first. But we finally confirmed transfer case by putting it up on a lift and standing underneath it, spinning the wheels. At least that's what the Jeep Tech did.

I have another clue though. I had been thinking that I was unable to hear the noise at higher speeds due to wind and road noise. But, fwiw, I realized yesterday that's not the case. The noise actually stops at about 20mph (ok,between 15-20). It starts when the vehicle begans to roll (2-3mph) and stops at just below 20. Then starts again when I slow down below 20.

I've never had the xfr case apart so I can't even imagine what has come loose inside there that would create those kinds of symptoms.

Rick HeBeJeepN '99 XJ Sport, Selec-Trac, Trac-Lok

Reply to
HeBeJeepN

I'm back. Meanwhile, I've been covered up with higher priorities and haven't had time to mess with the Jeep much. I have, however, talked to three different shops, one being a transmission specialist, and they've all told me that they don't work on transfer cases. They just replace them. And when I did have time to drain the case, I found something I wasn't expecting. Shredded rubbery stuff. Like pieces of a shredded O-ring or something. Found no metal chunks. However, I could see a bit of shiny metallic dust (aluminum I suspect). The kind of stuff you'd expect to be created when a chain is barely dragging across the bottom of a case. I almost needed to use a magnifying glass to see the specks.

So my next move is to find a NP242-J case and swap it out. It's going to be awhile before I can do that though, so here's my next question.

Is there any problem with me removing the front drive shaft and using the Jeep that way? I'm thinkin' it's the front axle that's spinning the chain in the TC, so if I disconnect the drive shaft and stay in

2wd, then maybe the chain won't spin? Or at least won't spin as much? The noise is not only irritating, but the metallic dust in the fluid can't be doing the bearings etc much good. I'd rather not screw it up any worse that it is cuz I'd like to keep it as a spare and work on it at my leisure (of which I hope to have again someday).

Anyhow, right now I'm just wondering if I can temporarily do away with the front drive shaft without creating some other sort of problem.

Anybody?

Reply to
HeBeJeepN

Well oookie doke then, I think I've answered my own question. I removed the front drive shaft and, as long as I keep it in 2wd, everything sounds and feels the way it should. No chain noise at all.

I drained the fluid again and refilled, just to make sure I had gotten the last of those metal specks out of there. I didn't see any at all this time so they must have all drained out the first time. Didn't see any rubbery stuff this time either.

So I think I'm good to go indefinitely in 2wd. I'll just add this transfer case to my rather lengthy and ever growing "Things to do" list for when I get a round tuit. HeBeJeepN '99 XJ Sport, Selec-Trac, Trac-Lok

Reply to
HeBeJeepN

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