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-   -   Unhappy differentials, groaning and complaining... (http://www.jeepgarage.org/f203/unhappy-differentials-groaning-and-complaining-49371.html)

Lhutter1 10-25-2012 12:24 PM

Unhappy differentials, groaning and complaining...
 
Hey guys,

Having some unhappy groaning noises coming from both differentials. I read posts on the subject and the recommendations were to change the fluid in both front and rear and the transfer case.

I used the NV247 fluid for the transfer case (Quadratrac II) and I used Valvoline 75w140 gear lube for Limited Slip in the front and rear. Did the figure 8s as recommended, but it's still not a happy camper after about 150 miles. A tech at Valvoline said that there is 4% limited slip additive in the gear lube. What else could it be? Thoughts?

Thanks!
Lorne

Frango100 10-25-2012 05:32 PM

Re: Unhappy differentials, groaning and complaining...
 
When you changed the fluids, did you see anything special to the gears? Metal flakes in the fluid? If there is not enough limited slip additive in the fluid, you will hear it when making turns. The smaller the turn, the more you will hear it.
Are you sure its coming from the diffs and not from drive shafts or wheel bearings?

chudsy 10-26-2012 02:20 AM

Re: Unhappy differentials, groaning and complaining...
 
Hi Frank,
I've been assured by the previous owner that the diffs oils have been done properly with the additive but sometimes I hear the 'groan' as the OP mentions.
Is there a problem by adding too much additive to the diffs??
Cheers
Paul.

99Wjlimited4.7 10-26-2012 03:16 AM

Re: Unhappy differentials, groaning and complaining...
 
Sorry don't really have any suggestions on what it could be if there were no metal flakes or anything when you last changed it, but seeing as the quadratracII doesn't have limited slip and they are open diffs the limited slip additive shouldn't matter... How many miles are on it?

Frango100 10-26-2012 05:42 AM

Re: Unhappy differentials, groaning and complaining...
 
Not sure where the limited slip additive is made of, but it probably doesn´t have the lubrication properties of the lubricant. Adding too much, could negatively influence the lubrication.
And the limited slip additive is just there to permit a bit of slip in the Vari-Lok. This is necessary when you make a turn and there is a speed difference between the left and the right wheels. When driving straight, the limited slip doesn´t do anything.

Lhutter1 10-26-2012 06:38 AM

Re: Unhappy differentials, groaning and complaining...
 
Inside looked ok near as I could tell. As for the limited slip goo, the guy at the dealership parts counter looked at the build sheet and told me to use 4 oz in the rear diff. and 2.5 in the front diff.. I didn't question it, but didn't want to pay dealer prices on the limited slip additive either, so I found the premixed stuff. I believe the sound is coming from the diffs. Sometimes front, sometimes rear, sometimes both. Is much worse since changing the fluids. Is there any sort of additive that goes in the transfer case? I just used the straight oil from the dealership. Chudsy asks an interesting question, can you put "too much" additive in the diffs?

Thanks!
L.

01grand 10-26-2012 08:34 AM

Re: Unhappy differentials, groaning and complaining...
 
Yes, you can put too much additive in. The additive is a friction modifier that makes the oil a little more slick and allows LIMITED slip on the clutches so that the wheels can still turn different speeds in turns, but too much slip and they will lock up to provide traction. From my understanding and in practice, too much additive will cause the diffs to slip more than they should, degrading the effects of the AWD system and causing it to act more like an open diff. Also, Frank is right it's just an additive, so too much would affect the lubrication properties of the oil, although I think you would have to use a lot to really hurt it.

The dealer guy is right, 4 oz. in the rear and 2.5 in the front diff, but that's if there is none in the oil you used. I don't know about Valvoline or Mobil1, but in my experience Royal Purple and Amsoil severe gear both have enough additive in them to not require any extra. If you used gear oil from the dealer you will need the above mentioned amounts of additive i'm sure. If you buy just an additive from a store, make sure it is ok for Jeeps, I've seen tubes of stuff at Advance that said right on them "not for Jeep quadra trac or quadra drive systems".

No additive is needed for the transfer case, the Mopar NV247 t-case fluid or equivalent hydrualic oil is already properly formulated for the case.

Also keep in mind that with a bad oil or a lack of friction modifier additive the diffs will make more of a chatter or chirping noise. If you are hearing a groan I would lean more towards bearings being the source.

Frango100 10-26-2012 09:54 AM

Re: Unhappy differentials, groaning and complaining...
 
If there is noise when driving straight, then it has nothing to do with not enough limited slip additive. When the noise is only there making turns, then yes, it probably has not enough additive.
But you are sure it comes from the diffs and not from wheel bearings or drive shaft joints?

Lhutter1 10-26-2012 10:18 AM

Re: Unhappy differentials, groaning and complaining...
 
It does only happen while turning, especially tight turns. Left turns seem to be worse for some reason. To be honest, I'm not sure it's the differentials, but it really sounds that way and sometimes it's front, sometimes rear. Also, it got much worse after changing the oil in the diffs. and transfer case. The tech at Valvoline said it has 4% additive. I'm not sure what percentage 2.5 oz and 4 oz breaks down to in the front and rear diffs. Reckon that would take a little math and a conversion chart! lol

L.

Frango100 10-26-2012 02:53 PM

Re: Unhappy differentials, groaning and complaining...
 
The manual is also not very clear on this. First they say to put 4 ounces ( 118ml ) in both front and rear diff, lateron they mention to put 2.5 ounces ( 70 ml ) in each.
Knowing the front diff (Dana 30) uses 1180ml, then with your 4% fluid you should have 47 ml, which is not enough. You could buy the additive and pour around 30 ml in the front diff.
For the rear diff it depends on which diff you have:
Dana 35 uses 1660 ml, so with your fluid you will have 60 ml of additive, which is also a bit too low.
Dana 44 uses 2240 ml, so with your fluid there is 89 ml of additive, which should be ok.
So i think that you can use maximum 118 ml of additive in each diff without any problems, but you could start with less to see if the noise already disappears.

Lhutter1 10-27-2012 09:02 AM

Re: Unhappy differentials, groaning and complaining...
 
Sounds like it's worth a shot, I'll try it this afternoon and get back.

Thanks!
L.

Lhutter1 10-28-2012 01:07 PM

Re: Unhappy differentials, groaning and complaining...
 
Great idea sneaking up on it! Not sure what the final amounts were, but after a few attempts I finally got it to a point where the grunting and groaning just barely went away. Mucho bettero! :) Thanks for the help (and math skills)! lol

Lorne


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