Whining

[manic]

Ideas on how to track down a whining noise appreciated. Manual 200tdi

The noise is noticeable when slowing down coming off the throttle, possibly because engine noise drowns it out at other times. It takes a bit of a run around before I notice it, after getting up to 60 - 80 kph travel.

It makes the noise even when coasting in neutral, and reduces in pitch as speed reduces.

I first suspected the alternator belt as I was unable to get it tight without the workshop tool but I cant reproduce the noise revving it with the bonnet up and it does not appear to be slipping so probably not that after all. Also thinking about it now, when coasting with engine at idle the noise pitch goes down as rolling speed reduces - so it cant be related to engine RPM.

I checked trans, gearbox, diff fluid levels and all good. The gearbox level is about 1.5cm below the fill plug but I figure thats good as full? Besides can a gearbox whine in neutral anyway?


diffs?
wheel bearings?
props?

A list of possibilities and ways to narrow them down would be most helpful.

[Blknight.aus]

get all the belts off and run it up.

[manic]

get all the belts off and run it up.
Could it still be the belts even though the pitch of the whine continues to follow my rolling speed whilst coasting in neutral with the engine at idle?

[Blknight.aus]

nope.

thats most likely going to be gear box tcase or diff pinion

[Yorkshire_Jon]

Check the centre box on the exhaust (below seat box)...

I once had a defer 200tdi where the internal baffles would whine at a certain speed... Took me bloomin' ages to track it down!

R
J

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[Killer]

Try coasting with the transfer case in neutral, if it doesn't whine then the noise would be in your gearbox.

Cheers, Mick.

[roobar_and_custard]

I would check your diffs. Sounds like a pinion whine. Due to the cut of the crown wheel and pinion gears, when on power the pinion is forced out of mesh and when off power is sucked into mesh.
If you have any in/out movement on the pinion input flanges (loose pinion bearings) then that is the most probable cause.
Try the trasfer case in neutral test first though. If the whine stops, then suspect gearbox, if the whine continues, look at the pinions.
Ian.

[ezyrama]

You could also try leaving the wife at home, works for me :angel::wasntme:

[manic]

I would check your diffs. Sounds like a pinion whine. Due to the cut of the crown wheel and pinion gears, when on power the pinion is forced out of mesh and when off power is sucked into mesh.
If you have any in/out movement on the pinion input flanges (loose pinion bearings) then that is the most probable cause.
Try the trasfer case in neutral test first though. If the whine stops, then suspect gearbox, if the whine continues, look at the pinions.
Ian.

The t-box and g-box are both pretty much 'new' from ashcrofts. Not yet done 1000km. Still I wouldn't rule them out based on that alone, although I will be pretty ****ed off it turns out to be one of those.

The diffs are most likely seeing as I have only ever topped them up and from the looks of things they could well be the original 1989's. Plus the car recently had a 2" lift with castor correction, so props/diff are my prime suspects

I will try the t-case neutral coast. So with gearbox in neutral the gearbox is not completely out of motion until t-case is also in neutral? I'll try an all neutral coast down from around 60-80kph and see what happens.

Only concern is rolling down the main road trying to get the t-case back into gear :o - my little diff stick is a wrestler!

I'm off to take her out for a quick run and see if I can get some syn-trans 75-85 for good measure.

[Yorkshire_Jon]

The t-box and g-box are both pretty much 'new' from ashcrofts. Not yet done 1000km

If the whining has just starte. I'd be looking at the new stuff...

Who fitted it and do you know it was done correctly?

Sounds very coincidental...

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[manic]

Went for a test drive, a short run and at low speed so the whine was barely audible but I have a good ear for it now and it disappeared as soon as I dropped the t-case into neutral.

So does that mean the whine is 100% from the t or g-box?


Not too pleased if that's the case.


It was installed by a landy mech in the UK, he's done a lot of work with defenders including building his own competition truck. I don't see how he could have installed it wrong?


I didn't find any syntrans 75-85w at supercheap yesterday so will try a few other places today. The g-box level is not right up to the fill plug but close enough I would have thought, the t-case is full and fresh... so maybe a full dose of the good lube in the g-box might help...

otherwise what gives - could it be caused by strain from the props? Anyway to figure if its the t or g-box making the noise?

Probably unrelated but my vdo speedo has started jumping around, could a worn plastic speedo gear in the t-case be making the noise?

[Yorkshire_Jon]

Can you replicate the noise in low box. If so, you could probably rule out the transfer box (at least half of it anyway!!).

Can you replicate the noise in all gears, or just one?

I still think you should rule out the centre section of the exhaust... Playing the percentages game, New gearbox & transfer box are unlikely to have failed but admittedly could let go if there has been an issue during the Ashcroft build of your boxes (again unlikely). If you exhaust is old, that could easily fail... I had to remove my cubby box and centre seat box cover and get the passenger to press a long screwdriver on the silencer and put the other end to his ear to pick up the whining pitch that it gave off. Like you my first thought was gearbox, but that ended up lasting another 60000 miles before I sold the vehicle!!!

I can't remember quite where the filler is on a 200tdi gearbox (its been a few years since I worked on one), however, its full when the oil runs out of the filler.

R
J

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[manic]

Can you replicate the noise in low box. If so, you could probably rule out the transfer box (at least half of it anyway!!).

Can you replicate the noise in all gears, or just one?

I still think you should rule out the centre section of the exhaust... Playing the percentages game, New gearbox & transfer box are unlikely to have failed but admittedly could let go if there has been an issue during the Ashcroft build of your boxes (again unlikely). If you exhaust is old, that could easily fail... I had to remove my cubby box and centre seat box cover and get the passenger to press a long screwdriver on the silencer and put the other end to his ear to pick up the whining pitch that it gave off. Like you my first thought was gearbox, but that ended up lasting another 60000 miles before I sold the vehicle!!!

I can't remember quite where the filler is on a 200tdi gearbox (its been a few years since I worked on one), however, its full when the oil runs out of the filler.

R
J

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I dropped my fuel tank today to sort out a fuel leak so I wont get a chance to drive it for week or so (I go slow)

I think I can rule out the exhaust because the sound cuts off as soon as I drop the TC into neutral. It does not matter what gear I am in, the sound is still there when the g-box is in neutral.

When I get the fuel tank sorted I will also drop in some new GBox oil and double check the t-box level. If I still get the whine on my next run I will try it in low range.

[manic]

Well got my leaky tank sorted and went for a run on fresh oils and lubed props. Still got a whine. With t-box in neutral it goes away so its gotta be the t-box.

After a hunt around the WWW it looks like these boxes are noisy for the majority, even new ones out of the factory can come with a whistle. A few posts about Ashcroft rebuilt LT230's say give it 1000miles for it to settle in (mines done 1000km). Something about new gears put in that might not sit in complete harmony with the other gears (pattern parts).

So I will wait and see if it gets any better/worse.

Is there a tried and tested premium oil for the LT230 that hushes them up a bit? Currently on Castrol EPX80-90.