Mystery transmission squeal??!?

[hingmy]

At certain loadings (road speed : engine load) I've a Loud mystery squeak (audible in the cab over the sound of a V  that within the bands it appears will increase/decrease according to revs/speed. If the clutch is dipped it dissapears while the clutch is down. If the engine + Main box are run in gear with the transfer box in neutral it isn't there. At tickover crawling speed it isn't there. The engine is a 3.5v8 with new clutch pack and hydraulic system put in last March and with less than 3k miles on it. The main box is a long stick LT77 built at Xmas with approx 300 miles on it. The transfer box is a secondhand late LT230 with x-drilled gear and app 37k miles on it. Oil levels are fine and both main and transfer boxes have had additives put in. All wheel-bearings, u-j's etc seem to be okay and from the driver's seat  the noise seems to be towards the front of the vehicle. Any ideas considered - I'm getting mightiiy annoyed with this ('tis ruining a great engine note) and if it is a main box problem I'd like to sort it before the warranty runs out

[Mace]

Can I suggest you remove one propshaft at a time and then take a run up the road (use difflock) just to eliminate the UJ's on the props. I had a similar squeel when one of my UJ's went but the bearing had seized so there appeared to be no play until it bust completely.

[hingmy]

Thanks for the reply. Certainly the less worrying of the two suggestions i've had so far plus a number of forae have included people questioning similar symptoms and getting similar replies to yours - much more welcome than the other idea that i might have to haul out the box and replace the clutch release bearing. It certainly makes sense 'cos the vehicle sat for most of the last 12 months due to company car and so far the wheel bearings have definitely needed a look-see, so the siezed u-j's are very feasible.
Cheers.

[muddyweb]

Clutch release bearings will more commonly make a noise when you depress the clutch, rather than when it is up, since that is when the bearing actually starts to do anything.

I'd agree with Mace, there are a few relatively straightforward checks to do before you start dismantling too much.

[hingmy]

mornin' Mr M Web,
i have to agree with you re c-r bearing, tho' I have noticed despite its relative youth that its already grumbling when depressed. Ho hum perhaps i should have have had the patience to have gone auto.
Right just need time to haul the props out...... looks like that sunday am before the hordes arrive.
BTW. Are you still up for Gt Dorset and for doing my decals.
Cheers.

[muddyweb]

Morning ;-)

Yes, no probs for the Steam Fair... just need to get the spare room cleared.

If I start now..........

[hingmy]

Ah, I understand fully. As ever chaos preceeds me.
Hows the auto?

[muddyweb]

Really nice.

It showed it's benefits at the Wingding on Saturday,  *really* smooth power delivery is a big help when you are driving around a bog.

Can't wait to compete it properly now   8)

[hingmy]

Ah would that small noise I just heard be the sound of the brain-cell being removed to be replaced by hooligan horns. ENJOY. Me? I'm stuck with occasional runs to keep the oil flowing and the local boy-racers in the climate of fear (for fear read burst ear-drums) to which they should become accustomed.

[baz]

Had Just that same problem on my defender it drove me mad. it turned out to be the front prop shaft joint. after the squeak came a vibration.I changed the prop and all is back to normal

At certain loadings (road speed : engine load) I've a Loud mystery squeak (audible in the cab over the sound of a V  that within the bands it appears will increase/decrease according to revs/speed. If the clutch is dipped it dissapears while the clutch is down. If the engine + Main box are run in gear with the transfer box in neutral it isn't there. At tickover crawling speed it isn't there. The engine is a 3.5v8 with new clutch pack and hydraulic system put in last March and with less than 3k miles on it. The main box is a long stick LT77 built at Xmas with approx 300 miles on it. The transfer box is a secondhand late LT230 with x-drilled gear and app 37k miles on it. Oil levels are fine and both main and transfer boxes have had additives put in. All wheel-bearings, u-j's etc seem to be okay and from the driver's seat  the noise seems to be towards the front of the vehicle. Any ideas considered - I'm getting mightiiy annoyed with this ('tis ruining a great engine note) and if it is a main box problem I'd like to sort it before the warranty runs out

[hingmy]

Problem solved> Muchos embarrassment.
'Twas the rear UJ on the front prop. When the noise was intermittent there had been no sign but having decided to go underneath and remove the props one at a time to run in diff-lock and see whether there was a change it was all to apparent what the problem was though. On the bright side an easy fix and on the even brighter side a v8 is very entertaining in rear wheel drive only.
Cheers all.
 :oops: