Whine in rear on LWB Y60. Help!

[RickZ]

I've got an annoying whine that occurs about 5 min after truck has warmed up. It only occurs above about 30kmph and doesn't change on cornering or depressing clutch or brake pedals. It won't make the noise when I've got the truck on blocks. Changing pads and diff oil made no difference either. Can't feel any play in wheel bearings.
Anyone help on this one? It sounds more the RHS of the vehicle. I don't want to replace the wheel bearing at $600 if that's not the fault. (Its done about 160K)
I've heard that they can develop a whine from a small bit of metal touching the top of the pinion bearing.
Turning the radio up certainly fixes it but I think this may only be short term!!
Does anyone have any experience with this? Hope someone can help me on this.

Cheers
Rick

[YNOT]

Does getting on and off the throttle change the noise?

From your description so far I would suspect either diff gears (hence the question above) or wheel bearings.

I wouldn't bother paying $600 to replace a wheel bearing when you can pick up a complete second hand rear diff for under $500.

Tony

[RickZ]

On and off the throttle doesn't change it either. It is intermittent when on the open road.
Cheers

[YNOT]

Are you sure it's not tyre noise?

What changes the noise when you are driving, speed, gear selected etc etc?

Tony

[RickZ]

Once the noise kicks in, (after the truck had warmed up for about 5 min) it only stops when dropping below about 30kmph. You can even freewheel and it sounds the same. Definitely not tyre noise. (I changed front and rear as the rear had worn to about 4mm while the fronts were still quite fresh). Sounds very similar to a stuck stone in the brakes but I've had all them off too!

Cheers
Rick

[YNOT]

Check for rocks between the brake dics and the backing plates.

Tony

[RickZ]

I wish it was that. I've had them all apart to clean them, blown them out with air and reassembled. Noise doesn't change with braking and only comes in after truck has warmed up. What about my pinion bearing idea?

Cheers

[White Elephant]

http://www.nissanpatrol.com.au/forums/showthread.php?6148-GQ-Patrol-Rear-end-squeal

I had exactly the same problem-read this thread it should give you a bit of history. I am actually only sorting mine out this weekend!

[YNOT]

I wish it was that. I've had them all apart to clean them, blown them out with air and reassembled. Noise doesn't change with braking and only comes in after truck has warmed up. What about my pinion bearing idea?

Cheers

Pinion bearings are a possibillity. From my experience you will hear the tone of the noise change as speed increases and decreases when pinion bearings are faulty.
There is a tin plate on the back of the pinion flange that covers/protects the pinion seal, if this is out of position it can rub on the front of the diff housing.

Tony

[RickZ]

Mmm, sounds extremely similar. I'd be keen to find out what your finding is as I'm still none the wiser. Thanks to Tony. I read somewhere else that it may be the pinion cover too. Mine won't whine on the blocks like yours so its hard to detect unless I hang my wife out the back at 30kmph, which she's not that happy about! ;-)
Cheers
Rick

[RickZ]

Hi Tony,
Is it easy to check? Presumably I've got to take the rear of the driveshaft off and unbolt the front housing on the diff?
I'm too new to get access to the manual for a look at the pics.

Cheers

Rick

[YNOT]

Hi Tony,
Is it easy to check? Presumably I've got to take the rear of the driveshaft off and unbolt the front housing on the diff?
I'm too new to get access to the manual for a look at the pics.

Cheers

Rick

Check by visual inspection, look for the tin plate rubbing on the front of the diff as you rotate the tailshaft.

Tony

[White Elephant]

Mmm, sounds extremely similar. I'd be keen to find out what your finding is as I'm still none the wiser. Thanks to Tony. I read somewhere else that it may be the pinion cover too. Mine won't whine on the blocks like yours so its hard to detect unless I hang my wife out the back at 30kmph, which she's not that happy about! ;-)
Cheers
Rick
lol, I'm sure she wouldn't be very happy about it!

Just an afterthought-when mine was up on the hoist I managed to stop the noise by pushing againt the hub/axle centre with the butt of a hammer handle(with the wheel off) which is part of the reason why we came up with the idea that it might be a worn housing. In any case, once I get it sorted out(may not have the time this weekend now) I will let you know. And if you manage to fix your's in the meantime I would be interested to know what it was!

[Dirtydog16]

I agree, I think you could look at the metal cap on the brearing from the rear tail shaft to diff. You could have a quick beau peep and then if you wanted to go further you could pull your rear tailshaft out and then get the cap off to make sure there is nothing stuck underneath. It would usually be unlikely but I once had some plastic that somehow got wrapped around and jammed up under the metal cap. Come to think of it I don't remember why I changed the bering and found it at the time. Maybe just preventative? I really don't rememer. I should write this stuff down when I do it and why!

You may also have teeth wear in your diff. A decent mechanic or a 4x4 specialist or a diff place would be able to tell you most likely from driving it around the block with you.

Cheers

[RickZ]

Thanks for that. Will have a go in the weekend. The noise is happening more consistently now and I'm tending towards the wheel bearing now. Cheers

[jash]

may sound silly but it may be hand brake drum?

[MudSlut]

Hmm... I am also suffering from a problem quite like this one, except it's only while you accelerate. I have just had my Pinion bearing replaced and it's still making the same sound but quieter.

[MudSlut]

I recently rebuilt my front and rear diffs, wine is completely gone now :) can actually talk to people in the cab and hear the UHF.

[MudSlut]

Oh and I should say that I replaced the bearings, pinion and crown gears, seals, swivel hub rebuild. So I'm not sure what part was causing the noise :/

[Silver]

You hit it at the beginning, Rick, the cause is insufficient use of the radio volume control settings. Increase the setting by turning the rotary knob clockwise, or the up arrow, until the noise becomes inaudible.

Thanks for sharing the problem and the causes and cures so far - only a matter of time until Silver starts to whine I suppose, being a gently maturing Mav and all

I think the metal plate Tony refers to is sometimes called a slinger - it is a disc between the uni and the front of the diff, located on the shaft and turning with it. External to the diff.