Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[Doctor Gollum]

Ok, third picture down. Looks goosed.

[terry paget]

The only way we diagnosed my faulty diff - a few years back now - after already changing a rear bearing that didn't solve the problem ... was to jack the rear of the car up and support on sturdy axle stands, then, with the wheels off, jack each rear suspension up on the bottom "knuckle" until the drive shafts looked level   ie .. in the "normal" driving position relative to the diff...... then to run the car in gear. As soon as I got under it was very obvious that it was the diff, both by the location of the noise and the vibration that could be felt when placing a hand on the diff.

Replacement used diff from RobG and all was, and still is, good ..

Thanks Entwood, and, indeed, thanks to all. I would like to avoid chnaging a rear wheel bearing unnecessarily. That seems like a good way to prove it is the diff.

[terry paget]

OSR subframe mount looks out of place...

Diff supported, do the drop if the two vertical mounting bolts are removed?

I see what you mean Doc. However, I have shot them again, and they both look the same.
Left hand sub frame mount

Right hand sub frame mount

[terry paget]

Has your son put new tyres on the back, since he's had it...

Ive had a couple of sets of cheap tyres that gave a god awful whine....was glad to get rid of them....just an idea 

Oh no, my sons don't buy tyres. Good idea, and I have known noisy tyres, but never this noisy.

[Doctor Gollum]

I would check both then, to rule them out.

[terry paget]

I would check both then, to rule them out.

Do you suspect that the rubber sound insulation is breached in the collapsed bushes, hence the cabin noise? Is this a recognised Omega problem?
I am out all tomorrow, so shall do Entwood's test Saturday. If that fails, how do I check out the sub frame bushes?

[Nick W]

I would check both then, to rule them out.

Do you suspect that the rubber sound insulation is breached in the collapsed bushes, hence the cabin noise? Is this a recognised Omega problem?
I am out all tomorrow, so shall do Entwood's test Saturday. If that fails, how do I check out the sub frame bushes?

mine got considerably quieter when I repaired a broken diff mount.

[Strangechap]

Can I suggest the centre propshaft bearing?

I had a noise that I thought was the diff going, but it didn't change with different loads as such.

If I remember correctly it was a 'hissing/whine'.

Ended up being the centre bearing, changed that. Sorted. Easy and cheap fix too, compared to the diff.

[Doctor Gollum]

Diff supported but not lifted, do they (the U shaped casings) drop if the two vertical mounting bolts are removed?

Expanded for clarity.

Check one side at the time so that the diff doesn't land on your head

[omega2018]

Are there any more tests I can perform?

Unlikely with yours as you have a whine but i had a rumble which was variously thought by rear passengers to be diff or wheel bearing but turned out to be hole in the top of the rear exhaust box.  easy to test, while moving switch the engine off and see if the noise stays on. with care obviously - danger of reduced braking and steering

[terry paget]

Can I suggest the centre propshaft bearing?

I had a noise that I thought was the diff going, but it didn't change with different loads as such.

If I remember correctly it was a 'hissing/whine'.

Ended up being the centre bearing, changed that. Sorted. Easy and cheap fix too, compared to the diff.

Thanks, good suggestion. It had occured to me too, mentioned in my second post. My only experience of central bearing trouble is the rubber mounting failing and the bearing banging about. But I appreciate it is a ball bearing that can fail, and become noisy. The noise I am hearing is new to me, and I have had diffs fail before. Also the location is not so clearly rear of car, the wife placed it more central, where the prop shaft bearing is.

Hissing whine is how she described it.

Another reason to perform the Entwood location test

[terry paget]

Diff supported but not lifted, do they (the U shaped casings) drop if the two vertical mounting bolts are removed?

Expanded for clarity.

Check one side at the time so that the diff doesn't land on your head

You recommend I support the diff, then detach one rear sub frame mount at a tinme and inspect, correct? If the mountings are loose I have a problem.

[Doctor Gollum]

As simple as that. No need to touch the horizontal bolt through the mounting. The U cage will either fall off or not...

Don't lift the diff... If using your pit, use a stout piece of timber across it with filler blocks to make up the difference to the diff casing.

[terry paget]

Source of noise was the differential. I performed the Entwood test and from below the car it was obvious.
One interesting complication occurred. I set the car up over the pit, rear suspension supported as in pic, asked son Dan to sit in the car and raise speedo reading to 35mph, and he failed. 'It won't rev Dad, even with foot hard on the floor', he said. I tried, he was right. Then I saw the TC light flashing. I unplugged an ABS sensor, then it revved all right.

[terry paget]

As simple as that. No need to touch the horizontal bolt through the mounting. The U cage will either fall off or not...

Don't lift the diff... If using your pit, use a stout piece of timber across it with filler blocks to make up the difference to the diff casing.

Thanks Doc, now I get it. As posted above, next job is to change the diff. Don't see a guide for that. I suppose it's exhaust off, drive shafts off, prop shaft rear end unbolt and lever out, then unbolt diff and lower. Replacement is the reverse of removal. At some stage I will check the rear suspension mounts, and pray they they do not drop down.