My rig's developed a whine at 65+, especially when going up hill or accelerating, that sounds like a gear whine - but it will fluctuate in intensity when you go over a bump or turn. It also makes a mild growl in the rear when turning to either left or right. From the driver's seat, it (growl) sounds like it comes from the right rear.

The growl sounds a little like a rear wheel bearing to me - does it take anything special to replace them on the 9-1/4? But the whine I can't place. The whine goes away if I am neither applying power nor slowing the vehicle with the motor holding back.

Anyone had anything like this happen to them?

_________________
05 CRD Sport in blue. Suncoast TC and ARP studs.

I have the Sealey timing kit I'll loan out.

Yes, I changed the Gear oil in the rear differential and it went away. The gear oil was pretty sludgy.

I also changed the gear oil in the front differential and the ATF fluid in the transfer case.

It made a world of difference by deadening the harmonic noise and wobble at high speed and it improved my MPG.

I was very impressed with the results. I never knew that old gear oil could have such of a detrimental effect on the driveline.

But, if your problem is a wheel bearing, then this fix will be useless.

_________________
2006 Liberty Limited CRD, Deep Beryl Green, Yeti tune, Arp studs, new cams, rockers, lifters, TB. "Green Monster"
2005 Liberty Sport CRD, Deep Beryl Green, GDE Hot Tune, ARP studs. "Rocket"
1982 Fiat 124 Spider Convertible. "Fiona"

Check your pinion bearings too. The flange that the driveshaft mounts up to should not have any play in it. If it does, the pinion bearings are bad and it will make the rearend hum, whine, growl, etc....