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eortizr 03-28-2011 08:37 AM

is that sound normal?
So, on my 2008 Laredo, if I'm going at more that 50mph and I release the throttle, I notice a little humming coming from like seem to be the rear diff. or Tcase. The sound is not loud at all, but is there. It only happens if I'm going above 40mph and while costing only, as soon as I apply some throttle it goes away.

So is that normal?, should I worry about?


JDM12 03-28-2011 08:59 AM

Re: is that sound normal?
Depends on what you define as normal. I've heard a lot of WK's have some sort of differential whine. I've had a slight whine at 65mph+ on light throttle only. If the sound has been present since new and is not getting worse....chances are it will be ok for the life of the vehicle. BUT it could potentially be caused by a bad bearing, or low fluid in the diff or xfer case.
I would change all fluids. If the sound remains, consider having your dealer look into a fix under warranty. At the very least have them inspect your ring/pinion, and pinion bearing for abnormal wear.

eortizr 03-28-2011 09:17 AM

Re: is that sound normal?
thanks for the reply, I bought the car used at a dealer, it has 70K miles on it, and the carfax does not shows any service done to it. I think I will start by changing the fluids.

any recommendations on the fluids?


Chaoul1 03-28-2011 09:22 AM

Re: is that sound normal?
I prefer you buy the Diff. Fluids/T-Case Fluids from the Dealership.

JDM12 03-28-2011 09:30 AM

Re: is that sound normal?
If your laredo has QTI, you can use the appropriate weight diff fluid in any brand really, Mobil1 or royal purple are fine. Transfer case for that system uses tranny fluid, i think i used valvoline or castrol's "chrysler" blend. If you have one of the more advanced systems the diff's might require the limited slip additive,and xfer case uses gear oil. In that case you're probably better of just getting everything from the dealer.

eortizr 03-28-2011 10:48 AM

Re: is that sound normal?
yes it the QT1, so for the Tcase is regular Tranny fluid and for the diff, just reguar diff fluid, right?

JDM12 03-28-2011 12:29 PM

Re: is that sound normal?
Right...double check everything here
and here

eortizr 03-28-2011 12:54 PM

Re: is that sound normal?
Great, Thx!

2005JGC 03-28-2011 01:14 PM

Re: is that sound normal?
if its "trail rated" im pretty sure your going to have the nv247 transfercase in which case you will need nv247 fluid from the dealer... I am fairly certain my 05 trail rated laredo has a nv247 case, its been so long since I looked at it. If it comes out clear (or dirty clear)its nv247, if it comes out red its atf+4.

Furthermore if you can climb under it and look at the placard on the case it will say what transfercase it is, on the WK if its not a NV247 its a something that requires atf+4

lewi3069 04-05-2011 02:19 PM

Re: is that sound normal?
For fluids I personally use Amsoil. But others use Royal Purple, Mobile1. I would stick to those... What engine do you have?

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