High pitched whine while driving.

[3 Sisters]

Before I waste cash with a mechanic, I was wondering if anyone could help diagnose my 91 V8 Discos problem.
It has a high pitched intermiten whine whilst driving, it's worse at lower speeds in any gear, and gets less when the motors under less load, it goes away with the clutch in, leading me to believe it's clutch bearings, but would rather someone with more knowledge to put their mind to it. It sounds similar to a fan belt. One mechanic thinks it's to high pitched to be the clutch, but he's not a landy specialist, and I can't imagine what else it could be.
If it's the clutch, would it be cheaper to just get a second hand box to put in, as mine crunches into reverse and is a bit hard to get to second anyway?
What about throwing an auto in instead?
I'm desperate to do it as cheaply as possible, as I'm short on funds, I'm in Katoomba NSWs, but will travel if the car can handle it.

[davros]

Few Q's - does it happen in neutral if you rev the engine?
Does it happen in both high and low range? A clutch thrust bearing will whine or "growl" when the pedal is depressed, then stops when it is released (as long as it's all functioning properly).
Have you checked the oil levels in all the boxes?
Where abouts does the whine appear to come from (front/back/left/right.
Is there any associated vibration?
Any other odd behaviour? (coolant loss etc)
Does it happen more if you have more electrical equipment on? ie lights, stereo etc

Dave

[bblaze]

could be an alternator diode, worth checking the charge system
cheers
blaze

[3 Sisters]

Few Q's - does it happen in neutral if you rev the engine? No
Does it happen in both high and low range?Yes, made an extra little noise once or twice with diff locks on, but probably nothing. A clutch thrust bearing will whine or "growl" when the pedal is depressed, then stops when it is released (as long as it's all functioning properly). Well this happens the other way around, so hopefully not a clutch issue.
Have you checked the oil levels in all the boxes? Just got the car back(700kms ago)from a full oil change, and or check, rang them just then to check if they'd checked the box, and they "definately did", however the bolt I'm fairly sure is the oil check, is very dirty and doesn't apear to have been opened recently(I did do 50km of dirt roads, but no oil residue around it).
Where abouts does the whine appear to come from (front/back/left/right.
Is there any associated vibration?Very hard to say, I guess engine, but could be box, I'll drive it again later to try and hear it better, it's booked in on tuesday for a mechanic to jack it up and try and find it, but I don't think it will make a peep if not under load, if you go to a higher gear, it barely does it.
Any other odd behaviour? (coolant loss etc)Uses a slight bit of coolant, bad nothing much, same with oil.
Does it happen more if you have more electrical equipment on? ie lights, stereo etcI'll have to check that, but it's been doing it with nothing on.

DaveThanks for your ideas.
I just drove it before my reply, and it didn't seem to do it as much when cold, and not as much overall as it did yesterday on a hot day(it's cold and drizzly here now).

[Bigbjorn]

Before I waste cash with a mechanic, I was wondering if anyone could help diagnose my 91 V8 Discos problem.
It has a high pitched intermiten whine whilst driving,

Have you considered divorce?

[3 Sisters]

That's some funny **** right there;)

[davros]

Hehe :)

I'm thinking most high pitched whistle/whines are non-lubricated bearings such as the alternator or serpentine belt idler bearings (on my TD5 this would include for example the fan bearing and the air-con bearing, and perhaps a few like the powere-steering bearing). Not sure where your water-pump sits but if it's the "old fashioned behing-the-fan" type then if its bearing is gone the seals are probly chewed too and you'd notice a coolant loss. Take off the fan belt and just try spinning and wobbling all the pulleys by hand, checking if they're lose or or rough. With the belt on it's hard to tell.
Also try swirling the car side to side whilst driving when the noise is occuring, to see if it's coming from a wheel, which may make a change when weight is applied to it by body roll - if you hear a big crunch sound though, it's probly an oncoming car!
I would usually think that a gearbox bearing or similar would be more of a humming or moaning sound, accompanied with vibration.

Dave

[Lucus]

Have you considered divorce?

All three of my cars have the same high pitched whine......I have narrowed it down to the LH front seat....odd that two fords and a RRC all have the same whine???:D:p:D


Im joking......its more of a shreak really.....:angel:

[3 Sisters]

Hehe :)

I'm thinking most high pitched whistle/whines are non-lubricated bearings such as the alternator or serpentine belt idler bearings (on my TD5 this would include for example the fan bearing and the air-con bearing, and perhaps a few like the powere-steering bearing). Not sure where your water-pump sits but if it's the "old fashioned behing-the-fan" type then if its bearing is gone the seals are probly chewed too and you'd notice a coolant loss. Take off the fan belt and just try spinning and wobbling all the pulleys by hand, checking if they're lose or or rough. With the belt on it's hard to tell.
Also try swirling the car side to side whilst driving when the noise is occuring, to see if it's coming from a wheel, which may make a change when weight is applied to it by body roll - if you hear a big crunch sound though, it's probly an oncoming car!
I would usually think that a gearbox bearing or similar would be more of a humming or moaning sound, accompanied with vibration.

Dave
It doesn't happen with the clutch in, or while engine breaking, so it'd nearly have to be clutch/gearbox related.
So if it's not a clutch bearing(as it's quiet with the clutch in)what about in the engine, what bearings are in there before the clutch?
I lubed all grease points under the car, and found 1 uni joint on each end of the front and rear shafts are very very sloppy, I've not driven it yet to see if the grease has solved anything. Could worn uni joints make a high pitched squeal when driving under load but not coasting or engine breaking?

[3 Sisters]

All three of my cars have the same high pitched whine......I have narrowed it down to the LH front seat....odd that two fords and a RRC all have the same whine???:D:p:D


Im joking......its more of a shreak really.....:angel:

Not sure with Fords, but often if you pull the left sun visor down the mirror can quieten the noise for a bit, but my Disco doesn't have a damned mirror there.:mad:
You can get a bit more time if you pepper the mirror with small dots, tiny lines, or smudges;)

[davros]

Perhaps perhaps... I have heard they can - youd probly feel some vibration too. If they need doing get on to it ASAP as a tailshaft falling onto the road gives your car a good chance to learn pole-vaulting... :) I too think to if it was engine the clutch in should make no diff so if it does it's prob not engine ancilleries.
When coasting along will it do it in neutral?
Also you could try to "replicate" a hill by left foot braking whilst trying to keep at the same speed (suggestion-slow!) and seeing if the noise starts. If you have a passenger sit in too, they can help listen where they think it is too. Even open the door and listen if it will happen at a low speed.
Sloppy and uni joint don't go together though - I'd do them even if they aren't the noise!

[loanrangie]

Have you considered divorce?

And i was going to say make her walk next time :p.

[3 Sisters]

I replaced all UNI joints, and the noise has gone. So it was rediculously worn UNIs, will keep an eye on them better in future. Nearly half the cir clips were missing and the bearings working their way out. Glad she gave a warning squeak.