Whirlling sound from Rear Diff

[Ducks]

Whirlling sound from Rear Diff / Aussie Locker (?)

There is this whirling sound coming from the back of the cruiser. Its pitch various with speed and not RPMs. It is fairly loud, similar to tire noise but somewhat higher pitch. This noise is now louder than the tires.

I installed an Aussie Locker in the rear diff 1200 miles ago. The gear oil is full. When I installed the locker, all the measurements were within the correct tolerances. The locker has worked great and the way it should. The noise has just started recently.

I am working a lot to get a project done for work and don't have time to pull the Aussie Locker apart to see if there is anything obviously wrong. But the 60 is my daily driver so I can't just stop using it.

Anyone have this problem before? It's kind of like driveline noise or something but don't know what it really is. Think it is o.k. to drive or am I going to lose my diff on the highway?

 

[kkt]

You may have the same noise as me. I think it is the transfer case, but it sounds like it is coming from the rear. Put you truck in low 4whd not locked and see if the noise gets much louder if so it is probably your transfer case. see link:
https://forum.ih8mud.com/60-series-wagons/196873-fj-62-whinning.html

 

[Ducks]

I'll check that out. But the noise is different for me than what you describe. It is always there whenever the tires are rolling. Anything above about 10mph, and there is some noise. It gets louder and somewhat higher in pitch as I drive faster. It could be the t-case but since I just worked on the rear diff, I guess that is initially the most likely candidate.

 

[Cruiserdrew]

It sounds like a bearing noise. In an original FJ60, my first guess would be pinion bearing, but you should have had noise before the Aussie locker.

Other possible sources, U-joints, wheel bearing, t-case output bearing, tires.

Any movement at the pinion flange?

Before you do anything drastic, put 85w-140 in the rear diff and see if it quiets down.

 

[Ducks]

Thanks Andrew. Actually I have 85w-140 in it right now. Aussie Locker recommends it with their lockers.

 

[Gargoyle]

I have fj60 and have had whirring noise also. In my case I discovered that the loudness varies between making a left curve and making a right curve at speed. If this is your case, then the gap is changing between the ring and pinion gear causing a whine - the correct gap or play is very critical.

Gargoyle

 

[Ducks]

Still haven't figured out what it is. Other people can't really hear it so I must just be paranoid. I'm starting to hear it less but I think that I am just getting used to it. I've had some mechanics look at it and they couldn't think of what it might be or really hear it. I guess I could go in and fiddle with the Aussie Locker to see if that makes any difference. I also may be switching thirds from 3.7 to 4.1, so I might see if that makes a difference.