rear end whine - L series 4wd wagon

YouTube · Post by **El_Freddo** » Thu Jan 01, 2009 2:33 pm

G'day all, Happy new year!

I've been putting up with a whine in the rear end that has developed since I replaced the rear bearings.

What's been done out back so far:

- rear bearings replaced
- rear suspension bushes replaced with nothane (spelling?) bushes
- rear disc brakes installed
- welded rear diff - driven without drive shaft in unless on a 4wd'n outting (don't take it out between 4wd tracks on the black top)

Initially I thought it may have been the rear diff creating the noise as it increases with speed, the most intense point of the noise is at about 60km/h, and the rear diff wasn't full of oil when I put it in, then it leaked some out. That seal was replaced along with the oil. It still whines.

After this I thought it may have been my bearings, found one a little loose then found their "correct" torque specs - 196 newton metres! Crazy. After fixing this the noise was still there. I havn't looked any further into the bearings.

My thinking now is that the rear tyres have worn un-evenly after 4wd'n in SA with the rear driveshafts in for the day from 4wd'n on Goolwa beach to random tracks between there and south of adelaide - a fair bit of black top work was done in this time, I noted the wheels fighting eachother with one squeeking in a pulse like manner as it let go of the traction around a corner.

From the driver's point of view it sounds like its from the rear left, the rear passengers think its from the rear right. One time when I was a passenger up front I thought it came from the centre...

Anyone got any ideas? I haven't had time to change the rear tyres with another set to see if they are the problem... If I have to I'll just live with it - the stereo is doing a good job of replacing the noise. I also don't know if pedestrians can hear it when I cruise past - the whine would have to fight with the lifter tick for pedestrains to hear it I reckon.

Any input appreciated.

Cheers

Bennie

brumbyrunner · Post by **brumbyrunner** » Thu Jan 01, 2009 4:03 pm

how are the uni-joints?

90brumby · Post by **90brumby** » Thu Jan 01, 2009 4:17 pm

are both rear drive shafts removed or just 1 if u take them both out it cant b the diff

is the noise still there in 4x4

AndrewT · Post by **AndrewT** » Thu Jan 01, 2009 4:50 pm

hmm there are a couple of potential problems you identified there, which you may not have fixed.

The rear diff was low on oil, this could have caused wear to the gears which makes the whine. Putting more oil in should prevent further wear, but not fix existing wear.

Same goes for the bearing that was loose. Tightening it may help to prevent any further wear from occurring but won't fix the existing wear.

The existing wear in both cases may be what is causing the noise...

YouTube · Post by **El_Freddo** » Thu Jan 01, 2009 7:26 pm

Righto:

The uni joints as far as I know are still going well - I've not had uni joints whine like this, they usually vibrate. That said, Ruby Scoo is near 390,00km so they could be on the way out.

One drive shaft is in at all times. I have thought about dropping the diff outand going for a drive to see what the difference is. You can do this with the L's by leaving the gearbox end of the driveshaft in the subi, the middle bearing holds up the end of the shaft.

I had thought there is damage in there AT, but there was no change in the noise at all. I would have thought that the noise in the diff would have dropped a little with the oil replaced. Quite a bit of oil came out, it wasn't like it was running dry just that I knew it didn't have all the oil in it that it should have. No 4wd'n was done after the noise appeared.

The bearings, this is an interesting case as I've had my old bearings very loose for a long time without noise - one time there was noise the castle nut had sheered through the pin and was on finger tight when the wheel was jacked up off the ground, after being tightened back up there was no problem til it came loose again... Before I replaced them each wheel would move a good 5mm left and right, the rear end would float along the road when trying to drive in a straight line.
I used a different pair of swing arms when I did the bearings, casings were knocked out and new ones put in. When I tighened them up to spec tentions there wasn't any change in the feeling of the drive in the subi.

Think I'll drop the rear diff out tomorrow given the chance and take it for a drive then report back. I'll check the uni joints while I'm under there too.

Thanks for the ideas so far.

Cheers

Bennie

Matatak · Post by **Matatak** » Thu Jan 01, 2009 8:18 pm

change your tyres over first.

then just remove the single driveshaft (may need to unbolt the moustache bar so you cna move the diff over a little bit to swing the whole shaft out. beats taking the whole diff out at first but)

90brumby · Post by **90brumby** » Thu Jan 01, 2009 8:24 pm

swap the rear tyres to the front and if the noise goes to the front its the tyres

AlpineRaven · Post by **AlpineRaven** » Fri Jan 02, 2009 7:23 pm

what specific speeds is the noise? or its like.. 60kmh onwards to 100-110 as it gets louder as faster? (recently i recognised the noise in a commodore, he thought it was tyres, axle bearings as he already replaced, and I said it was the diff as it got louder at 70plus kmh) so it could be that? Swap with other diff and see how it goes.. Doesnt hurt to try
Cheers
AP

YouTube · Post by **El_Freddo** » Sat Jan 03, 2009 5:44 pm

Nothing done on Ruby Scoo to check out this problem over the weekend, been busy working on the boat... Its got a 350 chev that was fired up for the first time in 2 years after some drive train mods and new head gaskets

Cheers

Bennie

chubby37 · Post by **chubby37** » Sat Jan 03, 2009 7:00 pm

i had a rear end whine once.....told my now ex to sit in the front and it went away....lol

YouTube · Post by **El_Freddo** » Sat Jan 03, 2009 10:33 pm

chubby37 wrote:i had a rear end whine once.....told my now ex to sit in the front and it went away....lol

Was waiting for something like this

Cheers

Bennie

AlpineRaven · Post by **AlpineRaven** » Sun Jan 04, 2009 10:05 am

Do you still have the welded diff?
Cheers
AP

YouTube · Post by **El_Freddo** » Fri Jan 09, 2009 9:34 am

Okay, tyres swapped front to rear. I noted quite a bit of slop in the only drive shaft on the rear.

Noise still in rear. After closer observation the noise winds up at about 30km/h, its at its loudest when travelling at 60km/h it seems to drop off as you gain speed but this could be due to other road noises.

At 60 km/h it seems to be radiating from the centre of the rear then at speed changes to the left. When cornering left the noise dissappears. Once out of the corner the noise re-appears. It also wavers over bumps and will change in noise with the very slightest change in speed

I'm hoping that its the rear shaft that's flogged out after 380k. As it generally travels at the same position with the exception of bumps and the little time it spends with loads, the CV cups hopefully are flogged out in this position - which is why I think it wavers over bumps and goes quiet around corners.

I really do not want this problem to be my bearings. I don't know when I'll get time to take the shaft out, hopefully this arvo if all goes well, otherwise it'll be this sunday.

AP: the welded diff still lives in the rear but only with one shaft to allow both wheels to spin freely while on the black top

The welded diff may be the reason for the shaft to flog out quicker than it normally would...

Thanks to all for your input so far, its just a game of illimination on my part now, I'll keep you updated when I can.

Cheers

Bennie

AndrewT · Post by **AndrewT** » Fri Jan 09, 2009 11:17 am

I'm now tipping it's the rear diff. Swap a known quiet one in and I bet the noise goes away.

YouTube · Post by **El_Freddo** » Wed Jan 14, 2009 4:38 pm

Again, haven't done anything more yet. I did get a nasty vibration that felt like it was coming from the centre of the subi - most likely the centre bearing or a uni joint I think. The interesting thing is that it appeared under load up a long hill then would dissappear when I hit a bump that shifted the balance of the car or by backing off the go faster (for an L series) pedal.
After that climb it has not occured the same again and its been too hot to get under the car to see what's moving under there...

Plan is to check the centre bearing and uni joints before taking out the last (left hand) drive shaft to see how the noise goes then. By only removing the rear left shaft I can still run the diff by engaging 4wd from a stand still - then at speed I can disengage it to see if the noise (if still present) will slow with the momentum of the diff - to re-engage the diff I realise I'll have to pull over and stop to do it as at speed the rear diff will not be moving as it would normally with the drive shafts installed...

The other night on the weekend I also found out that the noise is hard to pin point - I moved over the back seat, put my ear to each guard from inside the car where the noise could be heard from each side, stuck my head out the side of the subi at 60km/h and you cannot hear any whining. I stood on the side walk as my gf drove past at 60km/h listening for the noise - you cannot hear it from outside the car which surprises me.

Further updates will come.

YouTube · Post by **El_Freddo** » Sat Jan 17, 2009 10:08 am

AndrewT wrote:I'm now tipping it's the rear diff. Swap a known quiet one in and I bet the noise goes away.

Diff is out - problem is that the noise is still there - meaning that my problem is the bearings

Just short of replacing the bearings, what's another option I can try before going this far?

Cheers

Bennie

PS I've also got a pin stuck in the left CV and stub axle - problem here is that I used another pin to help hammer out the dodgy one, now both are stuck... fun fun.

AndrewT · Post by **AndrewT** » Sat Jan 17, 2009 12:06 pm

Maybe replace the hubs with a different pair which are known to be quiet, that should be easier than putting new bearings in your ones, if you have access to some spares anyways.

YouTube · Post by **El_Freddo** » Mon Jan 19, 2009 3:33 pm

AT, the second set of swing arms I have are the old one's I just replaced. I think I'll save my money, put up with the whine for now then put in another set of bearings following the torque specs very closely to avoid the same situation...

I can't put the new bearings in the second set of swing arms as I also replaced the suspension bushes at the same time - I also did the discs (can't see how these would make the noise so havn't made a big thing about them)...

Cheers

Bennie

djparker · Post by **djparker** » Mon Sep 07, 2009 6:45 pm

Hi,
I wonder if you managed to fix the rear end noise. I have a 91 l series with a whine that seems to be coming from the rear passenger side wheel area. I replaced the bearing on that side last weekend and it has made no difference. Like your problem the whine starts at about 30 and is loudest at 60. Over 60 it fades out a bit, but is still there. Also the whine stops when going around left handers.

Did you ever get the bottom of your problem? I am replacing the other side bearing this weekend to see if that fixes it. Fingers crossed

phillatdarwin · Post by **phillatdarwin** » Mon Sep 07, 2009 10:25 pm

the whine stops when going around left handers as it is no wate on the left hand side wear the problem is

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rear end whine - L series 4wd wagon

rear end whine - L series 4wd wagon

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