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99 GC Limited: Growling noise from rear while turning L/R low speed (sound included)

3K views 22 replies 4 participants last post by  caliskier 
#1 ·
Hi all,

My beloved 1999 grand cherokee limited makes a loud growling sound from the rear when I am driving in parking lots, especially when I am turning hard into a parking space. Reverse / Forward / Left / Right does not seam to matter, just a low loud growling sound at low speed while turning. Straight driving forward and reverse or turning at higher speeds I do not hear it. It sounds exactly like what you here in the included video... start it at 0.20



Can anyone tell me what this is?
 
#3 ·
Sounds like you have a VariLoc rear diff and it's time to change the rear diff lube and also add 4 ounces of Mopar limited slip additive. The clutches are quite aggressive and will make that noise on tight turns. The diff has sensed that one tire is going faster than the other and the clutches are partially engaging and doing their very best to keep both rear tires rotating at the same speed.
 
#5 ·
I have the quadra-drive, and this has been doing this for over a year, so now I am getting worried and am going to stop driving it. I went out and bought this stuff last year and have been ignoring it. Shame on me...Is this the right stuff?


and this


What is procedure for doing this?
 
#8 ·
Yep. That's a decent overview. You won't have as much room to work with as this guy because you have a WJ and there's a big gas tank back there.
Getting the cover aligned without making a mess can be a hassle due to the sway bar in the way. I recommend using a skinny phillips screwdriver as a locating pin to help. Slide it through one of the holes in the cover and into the matching hole in the diff, then ease the cover into place. When positioned, hold cover with one hand, screwdriver with the other, and get a bolt started with the third. Ok maybe let go of the screwdriver.
You don't need a giant tube of silicone like this guy, you can get smaller hand-size tubes of Permatex. I used the green tube but it probably doesn't matter much, grey tube works too. Or get the Lubelocker.
I could never get my cover to come off as easy as this guy did. Not much room to swing a hammer under the WJ.
 
#7 ·
That's the right stuff. I am paranoid about this maintenance because mine went through two LSDs (bearings and all) while it was still under warranty and having the stealership service it, so now I service it myself basically every year and no problems since. But not everyone has the same XP so maybe yours is fine and just needs fluids.
Pretty simple procedure. Drain, clean, fill.

Put a drain pan under the pumpkin, remove the bolts on the cover. Leave a couple loosely attached at the top. Pry the cover back, may be stuck pretty good. Fluid is pretty slimy and stinky, drain it into the pan. Inspect for metal flakes which would be bad news. Clean the old gasket off the diff and the cover. Remove rubber fill plug from the cover.

New gaskets for the Dana 44a (rear) are hard to find, Lubelocker is good and easy, but expensive. Factory procedure is to use silicone gasket maker: run a bead all around the edge of the cover and ease it back into place without making a huge mess, can be a hassle but doable. Place a couple of bolts in loosely to position the cover, then get all the bolts started. Now twist them all in until they are finger tight. Use a criss-cross alternating bolt pattern. This spreads the silicone evenly over the sealing surface.

Next bits vary by mechanic ... Let it sit there for a while to let the silicone begin curing, maybe 30-60 minutes, then snug (not tight) all those bolts down with a wrench. No need to torque to spec yet. Pause again for more curing time. Then finally torque to factory spec 30 ft-lb if you have a torque wrench, or 1/3 grunt if you don't.
Skip curing times if you get a solid gasket.

Now refill with fluids. I got a plastic hand pump/hose for this (any parts store really) which screws into the oil bottle. Keep filling with 75w-140 until it runs out of the hole, nearly 5 pints worth by spec but I don't think I've ever got more than 4 in there. Don't forget the FM before it's full. Replace fill plug.

For cleanup, funnel the old oil into the used bottles and recycle at the parts store.
A messy job but not hard.
Drive it around, it could take a while before the fluid gets worked in and the groaning goes away.
 
#9 ·
Also I would recommend a brass wire hand brush not a steel wire wheel for cleanup. Less likely to mar the mating surfaces with brass.
I've also never sprayed brake cleaner all up in the diff like that. Probably ok for open diff but with the LSD, not sure. Usually just clean the cover real good and let the diff drip for a while ...
 
#10 ·
Thank you very much for the guidance and help Gman! "New gaskets for the Dana 44a (rear) are hard to find, Lubelocker is good and easy, but expensive." Is that what I have a Dana44a?

This right? https://www.amazon.com/LUBE-LOCKER-...575751836&s=automotive&sr=1-8#customerReviews

I should respect my Grand Cherokee, the reason I have not done this yet is because I didn't know how serious it was and I thinking it would be a PITA. I change the transmission fluid on my Honda Odyssey every other oil change (12-15k miles) because they are so tempermental. But that takes like 20 min.

I need to respect this Jeep, its in really good shape (interior /exterior) and its my driver to go skiing this winter. I went out and found this... http://www.wjjeeps.com/service/maintenance_wj.htm#AIRFILTER

1. Air Cleaner Filter - No worries
2. Engine oil - No worries
3. Chassis Lube? What is that?


4. Front Axle - Looks like same fluid required as rear axle, correct, actually it lists two for the front for 1999: SAE 80W-90 gear lube and SAE 75W-140 Synthetic. Which one is it, I bought this:

Found a 40min video i will watch later...



5. Transfer Case - I assume I have NV247 because I have the Quadra-Drive, correct?
Found a 15 min video i will watch later...


6. Transmission:
I think I need to purchase this, correct?
Transmission Filter 1 5013470AC*
Transmission Filter 2 4799662AB
Transmission Oil Mopar® ATF +4, type 9602
30 min Video i can watch later...
 
#11 ·
Look at the cover on your rear diff. If it is an oval, you have a Dana 35. If it is multi-sided trapezoid kind of shape, it is a Dana 44a, NOT to be confused with a Dana 44. They are quite different. 44a is aluminum housing, so slap a magnet against the housing (not the cover), if it falls off it is aluminum D44a, if it sticks it is iron D35. I think Quadra-drives were all D44a rears but not sure.

There are only two spots to lube on the factory chassis: front end upper ball joints. One zerk fitting behind each wheel in front. Get a grease gun, red general purpose grease like what you found is good I think, pop the hose on the zerk, three squirts. Some people have replaced tie rod ends and other joints with greasable aftermarket parts, so if you are not original owner take a look around for more zerks.

Front axle is Dana 30 and you should be able to use the 80w-90 you got plus FM. QD has LSD front and rear so needs FM. Technically you could run 80w-90 in the rear as well, but as I mentioned, my experience has made me paranoid about the Varilok diffs so I only put 75w-140 in mine.

Yes, you have the NV 247. Only use the Mopar fluid in there, otherwise ... heartache.

Tranny fluid/filter change is the messiest job of the bunch because of the large footprint. You have to drop the pan to change the filter exposing the whole transmission which drips the whole time. Recommend a large tray to catch it ... or a large piece of cardboard to soak it up and toss in the trash. The filters you identified should do the trick if you have 4x4. Don't forget to get a gasket too ... Or more gasket maker. If money is no object, consider getting a new pan with a drain plug to make future fluid changes much easier.
 
#12 ·
Thanks again brother!
My dad was he original owner and put a new engine in it 40k miles ago before I bought it from him 4 years ago.
"[Transmission]...consider getting a new pan with a drain plug" <<Totally, how often should you do the transmission job?
Is there something like that for the rear and front diff so I don't have to keep pulling the cover off every year?

This is going to be my snowmobile for years if I can keep it running, but I don't like to spend a lot of time changing fluid.
 
#14 ·
No, I have not found one, the one that exists: https://yourcovers.com/diffcover_11045.php will not fit my 99 unless I have a lift kit, it runs into the sway bar.

So I am going to do the rear diff using the lube lock, thanks for that suggestion, so tight in there I don not want to mess with silicone getting messed up while I try to install. Should I or do I need to add a little silicone with lube lock gasket install?
 
#19 ·
The first time I replaced the lube in mine it took about a week for the noises to completely go away when making sharp turns. It takes a while for the friction modifier to work its way in between the clutches and do its magic. The noises didn't suddenly stop, they just faded away over a few days of driving.
 
#20 ·
Thanks GMan and Harry,

I will be gentle with it and see what happens. Some extra information...
1. The oil that I used was the correct oil and as was the FM that I put in it, however I bought it 2 years ago and it has been sitting in the garage. I figured its oil and it should not go bad, its meant to get hot. I had a fresh bottle too and it all looked the same.
2. right after finishing the lube change, I had read that I needed to do figure 8s, it made no noise for the first one but then started after that and sounded worse.

I will be gentle with it this week and pray, I do not want to replace or overhaul the dif
 
#23 ·
Well I have been driving it off and on for about 3 weeks, maybe about 20 times. It seams to be getting better without me doing anything more to it. Every once in a while it makes a noise when parking but nothing like it did before. 10 days ago I purchased more oil from the dealership to do another change, but I may take it back.

Really appreciate everyone's help here especially GmanWJ
 
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