Recently I have noticed a high pitched harmonic whine at 70mph. As soon as ilet off the gas it goes away. It is def tied to vehicle speed and not engine speed. I noticed last week when working on the Jeep that the rear driveshaft is slinging grease, however i asked the advice of a mechanic next to my work that works on truck/humvees and he said it sounded more like a ring/pinion issue.

Any thoughts? More important what would be the damage in time/hours? Im hoping for just the DS as that is a simple/cheapish upgrade.

Thank you for your help!!


>> I have the Rancho 4" sport lift on stock DS and unfortuanly rarley go offroad

 

Slinging grease ? The front shaft has had it. Remove it just do NOT go in 4wd.

Are you running their brackets ? What's you caster angle at ?

 

Im sorry for not clairifying . . . It is the rear driveshaft that is slinging grease at the transfercase side.

>> fixed OP

 

Need to narrow it down,if left unchecked could get $$$. Almost sounds like a bearing going dry

 

Did you have gears installed recently? The drive side of the R&P could be set up improperly and the coast side is OK? Also I have seen pinion bearings make this noise. Just a thought.

 

gears have 20k on them . . i changed the diff fluid this weekend though and there was def. water in there as the fluid was a light brown and more of a water like consistency. I'm beginning to think my rear gears are f'd and i guess my next step should be to have them checked out.

 

Water definitely will etch the gears over time. I have seen pinion bearings do this and they are usually louder with speed and have a distinct whine to them. Probably time to inspect the differential for sure.