Knock in rear with Dana 44

[Outback Jack]

You'll probably have to pay out of pocket for the gear oil change. Make sure they add the friction modifier. My dealer did not with the new axle replacement, so I replaced the fluid again with the modifier per the service manual.

Which friction modifier did you use?

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[HiJinx69]

Which friction modifier did you use?

Mopar's. It's about 10 bucks at the dealer.

 

[D60]

I read through the majority of all these last night. Today I tried to duplicate the scenario to see if I heard any clunking or strange rear sounds. I did not hear anything. I have a 2019 JL 2 door sport s, 3.6, automatic, with the LSD/AntiSpin option. It has 3000 miles on it. I think I will make an appointment with the local dealer to get the rear fluid change, and ask them to see if it burned. Like I said I don't have the clunk, but like most I fear it will show up later, after warranty.

It's not really an issue of "burnt" fluid but dirty from clutch pack material....then metal flakes from spider and side gears playing footsie

Honestly, if nothing is happening now I think you'll be wasting your time and money with the dealer, but maybe not.

 

[YellowJL]

Kind of a shame, paid extra for the LSD because my old TJ was so great about getting me out of the snow where I live (it was a 2000 model Sport with LSD). I am hopeful they will have a fix for the clutch packs. From what I have read over the past few days, my old TJ probably had worn out clutches and was no longer LSD with 230,000 miles on it lol. Man that Jeep never got stuck, and my private drive is a mile back into the woods. All that being said, perhaps the LSD thing is not all it is cracked up too be anyway over time. Seems the best is lockers, and I think I also read there are now lockers for the rear that is on the JL models with LSD. My guess is the LSD goes away completely and people just go with lockers when or if needed.

I tried again last night to hear the noise, creeping along between 1 - 7 miles per hour (hard to keep it so slow). I thought maybe I might have heard it, but it might have been my imagination, it was so slight. Certainly wasn't anything really noticeable. Still, I like to ward off trouble when I can. I realize the dealer probably will not do anything and I should maybe wait until it gets loud, if it does. Also thinking about buying an extended plan just in case, since I need this one to last a few years.

 

[Outback Jack]

Mopar's. It's about 10 bucks at the dealer.

I this it?:
Genuine Mopar Fluid 4318060AC Limited Slip Additive - 4 oz. Bottle

 

[Outback Jack]

It's not really an issue of "burnt" fluid but dirty from clutch pack material....then metal flakes from spider and side gears playing footsie

Honestly, if nothing is happening now I think you'll be wasting your time and money with the dealer, but maybe not.

My rear diff fluid at 10,500 miles... I have more pics that show a small black chunk that was stuck in the end of the tube when I pulled it out. Dealerships said it's normal considering the larger tires I put on it at 8,000 miles...

 

[HiJinx69]

I this it?:
Genuine Mopar Fluid 4318060AC Limited Slip Additive - 4 oz. Bottle

Friction Modifier, yes.

 

[ztobro]

Currently trying to get this resolved on my Wrangler. No real help from the dealership yet. They took my Jeep for a spin by themselves and "couldn't replicate the issue" and when I went on a drive with a tech they "couldn't hear anything" out of the normal when I replicated it. Same issues as whats being said in earlier posts, clunk from the rear diff when letting off the gas and coasting at lower speeds (40 mph and below). Working with JeepCares to try and keep things moving. Showed the tech this video I took and he said something along the lines of "well they'll make some sound when there's no load on the diff"... alrighty.

 

[stil2low]

Currently trying to get this resolved on my Wrangler. No real help from the dealership yet. They took my Jeep for a spin by themselves and "couldn't replicate the issue" and when I went on a drive with a tech they "couldn't hear anything" out of the normal when I replicated it. Same issues as whats being said in earlier posts, clunk from the rear diff when letting off the gas and coasting at lower speeds (40 mph and below). Working with JeepCares to try and keep things moving. Showed the tech this video I took and he said something along the lines of "well they'll make some sound when there's no load on the diff"... alrighty.

The tech is correct, most differentials will clack like that changing direction while suspended and no load. What you are hearing is the lash (space between gears) in the spiders and ring and pinion.

 

[ztobro]

The tech is correct, most differentials will clack like that changing direction while suspended and no load. What you are hearing is the lash (space between gears) in the spiders and ring and pinion.

I just feel like that's awfully loud to be normal though. I'm by no means a mechanic but I've driven two other JL's with the same setup (optional rear Dana44 with the LSD, one has the 3.6L and the other a 2.0L like mine) and neither one of them have the knocking issue. Haven't been able to jack those up to see if there is similar gear noise though.

 

[4LowPhoto]

Dropping mine back off at a new dealer this weekend with full support of Jeep Cares and Diff specialists at the dealer going through it. Fingers crossed.

 

[jlroman2]

Dealer replaced the rear driveshaft but they mentioned the noise is still there. I’ve been pushing for them to look inside the rear differential since I dropped it off but they said “they’re not there yet.” Like what? Now they might want me to bring in my old tires.

 

[jlroman2]

Update on my Jeep: after an entire month in the shop it is finally fixed. They ended up replacing the innards of the rear diff and there is no more knocking. I hope that it stays that way but I guess we will see

One month later update?

 

[Arrowhead]

The tech is correct, most differentials will clack like that changing direction while suspended and no load. What you are hearing is the lash (space between gears) in the spiders and ring and pinion.

But there's also no way you should be able to freely spin the tires in opposite directions on an LS diff unless it's already fried.

 

[Arrowhead]

Problem solved! I acquired a set of Rubicon takeoffs and swapped them over the weekend. No more clunk and gets me all the upgrades at less than half the cost of upgrading the stock axles with similar equipment. Being that I own them and can't warranty them anymore, I can't wait to open up the the rear LSD to see whats really going on in there.

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