Diff noise

[KJowner]

Hi,
I've got an export 2.5 crd, a few days ago a horrible howling noise started coming from the rear at 50 to 60 mph, only under power, goes silent if I take my foot off. I think it's the pinion bearing, diff is 4.10 with Traklock. Anyone else had this before I start ripping it to bits?

 

[LibertyTC]

How many miles on the kj now? Have you removed the rear diff cover for an inspection? Check for play/ wear & particulate matter?
Rear diff trac-lok does require the 4 ounce bottle of Mopar limited slip additive.
Rear diff should have good ole dino gear oil, with the limited slip additive.
Regular service of rear diff should be done every 30k miles. ( dealer recommends every 20k)
The trak-lok has clutch packs, I had mine replaced by dealer, under warranty, early in life on mine. So far so good, it likes diff lube changed often.
Specialist tools required, probably best to to leave it to a professional re-builder/ diff shop.

 

[KJowner]

It's done 130,000 miles, I changed the oil last year when I bought it, the clutch pack was groaning on tight corners. I will drop the cover off when the rain stops and see if I've got any shrapnel in there. There is no obvious play anywhere, I took the propshaft off to check the UJs sadly they were fine.... and the wheel bearings are all tight and smooth. I doubt there is anyone round here who can rebuild the diff (I'm in the UK) but I have a machine shop & I've just found another Jeep in a nearby scrapyard so a couple of options.

 

[turblediesel]

The service manual has a procedure for the tracloc differential to free up stuck clutch plates. Basically do about a dozen slow figure eights in a parking lot. Howls are usually a bearing noise though.

 

[KJowner]

Yeah, that's what it sounds like to me sadly.

 

[tommudd]

iF GOING TO JUNKYARD MAKE SURE IT HAS SAME GEAR RATIO

 

[duderz7]

Download the FSM for guidance as well as there are a lot of videos online for rebuilding the Chrysler 8.25 with trac‐loc as it was a pretty common axle. I do have a few "professionals" in my area that could do the work, but I will be doing it myself soon because the cost of labor is too high. The way I figured it is the few special tools needed cost 1/4 the amount in labor. Plus you said you have access to a machine shop, that could be very helpful. And I'll come out of it with experience and tools. If it's just your clutch pack you won't even have to remove the the pinion gear which will save you a lot of trouble. It may still be a bit before I get to do mine, but I'll be sharing my experiences on this site on my current thread "diff and axle hunting". I've got faith in you, good luck.

 

[KJowner]

Thanks all, lucky all the European KJ 2.5 CRD are 4.10 - unless someone has been playing! So if I can get one I will rebuild mine over winter as a spare. Need to get it sorted out before the weather turns. The sills need a bit of attention too!

 

[tommudd]

Yes they were but I always double check to make sure

 

[KJowner]

Good point Tom, is there a ratio tag anywhere on the axle? Can't see one on mine.

 

[KJowner]

Well I've been to the scrapyard, it's a 2.4 petrol, the axle is cheap but can't see any markings on it for ratio??

 

[duderz7]

There is a tag on the front diff on lower cover bolt. Here in the USA a 2.4 petrol is always 4.10.

 

[KJowner]

Cheers I'll look round the front.

 

[JRB]

If you can't find the tag, you can put marks on the ring gear and the pinion flange side, and spin the pinion.

Little over 4 turns for the 4.10s or less by a 1/4 turn for the 3.73s.

Granted this is a lot easier when it's out of the vehicle.

 

[KJowner]

Yard are going to lift it out of the sea of mud it's sitting in for me so I can get a better look + get the nice stainless side bars off it

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[turblediesel]

If you can't find the tag, you can put marks on the ring gear and the pinion flange side, and spin the pinion.

Little over 4 turns for the 4.10s or less by a 1/4 turn for the 3.73s.

Granted this is a lot easier when it's out of the vehicle.

US CRDs came with 3.55 (3.56?).

 

[Billwill]

My 2002 Export 2.5 L CRD here in SA has a tag on the right rear axle stating 4.10!

At one stage long ago my Jeep felt a bit funny in tight turns so I drained the rear diff...filled with a good gear oil and the Mopar Additive.

Did a few tight "figure 8s" on loose grass and had no more problems 20 years and 200,000 kms later and repeated this oil change 2 more times!

 

[KJowner]

Mine was fine until my wife borrowed it when I was at work, I got the dreaded call.... The car's making a funny noise.

It's at its loudest in a straight line cruising between 50 and 60 in 4 & 5 gear + goes silent on overrun so all I can think is pinion bearing failure. I'm collecting another axle and a few other goodies from a local scrapyard but my hands are tied at the moment because I need to get the sills done before I go back to work & I can change an axle in the damp but I can't weld & paint.

 

[JRB]

US CRDs came with 3.55 (3.56?).

Oh did they, good to know.

My v6 6 speed manual came with those same gears.

 

[KJowner]

Picked up a 4.1 axle today from a 2.4, no LSD sadly but the backplates are more solid than mine! Strangely someone had gone to the effort of taking all the studs out of one of the wheel flanges??

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Took a couple of alloys with nice Yoks to match the ones on my Jeep too.

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