Hi Guys just an update. Changed to 80-90 oil as per Bexhill gearboxes thoughts, slightly less noise but hasn’t solved issue (waste of £40 oil). Now waiting on book to see what other things to check.
Not sure if this highlights anything, I put the diff lock on and slowly pulled away on gravel drive and the rear wheels locked up and dragged?

That cannot be right.
 
Doesn't sound right to me either.
Don't know how to test these.
I'd hazard a guess that James Martin might but I don't know if he's been in for a while.

Does it drives normally if you then disengage the difflock?
Difflock on this should be vacuum engaged, could engaging it be affecting part of the braking circuit & putting the rear brakes on?

I also wonder if something has failed in the box but will still turn & engaging difflock causes it to jam. I have no idea what it might be but it may also explain your noise.
 
Doesn't sound right to me either.
Don't know how to test these.
I'd hazard a guess that James Martin might but I don't know if he's been in for a while.

Does it drives normally if you then disengage the difflock?
Difflock on this should be vacuum engaged, could engaging it be affecting part of the braking circuit & putting the rear brakes on?

I also wonder if something has failed in the box but will still turn & engaging difflock causes it to jam. I have no idea what it might be but it may also explain your noise.
 
Mmmmm that was my thoughts. Can’t be locking brakes on as its all too basic. I would assume it locks something in the transfer box and yes perhaps that’s the **** metal noise it’s making after driven half a mile. Noise gets louder and louder (no metal in the two oil changes it’s had in 750 miles). I’ve replaced everything now as in everything on the 1978 RRC running gear, checked both diffs a light back lash but all good and drive shafts all round. yes it’s jacked up 2” but it now has wide angle props front and back, the only thing left to fit is the cranked rear trailing arms, but I can’t see that changing anything. A job this weekend and of course I will try the diff lock again.
yes you’re right on the old LT95 the diff lock is done by air on a pull button and a light comes on to let you know its engaged.
My guess it the vacuum diff lock, locks front and rear drive together, all of the brakes are separate standard calipers leading to servo, non abs.
 
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Mmmmm that was my thoughts. Can’t be locking brakes on as its all too basic. I would assume it locks something in the transfer box and yes perhaps that’s the **** metal noise it’s making after driven half a mile. Noise gets louder and louder (no metal in the two oil changes it’s had in 750 miles). I’ve replaced everything now as in everything on the 1978 RRC running gear, checked both diffs a light back lash but all good and drive shafts all round. yes it’s jacked up 2” but it now has wide angle props front and back, the only thing left to fit is the cranked rear trailing arms, but I can’t see that changing anything. A job this weekend and of course I will try the diff lock again.
yes you’re right on the old LT95 the diff lock is done by air on a pull button and a light comes on to let you know its engaged.
My guess it the vacuum diff lock, locks front and rear drive together, all of the brakes are separate standard calipers leading to servo, non abs.
Is there a diff lock in the rear diff? Locking the centre diff should not cause the rear wheels to lock.
 
Something seriously wrong there, I would be tempted to remove the rear drive shafts and the rear prop and see what difference that makes if any. Be careful though, you wont have a hand brake.
 
Something seriously wrong there, I would be tempted to remove the rear drive shafts and the rear prop and see what difference that makes if any. Be careful though, you wont have a hand brake.
I did wonder if that was possible as it had the noise when I purchased it but I thought it was just because the gearbox was knackered (and it was even cracked). My other thought was get it up on axle stands, run it and then go round with a stethoscope
 
My other thought was get it up on axle stands, run it and then go round with a stethoscope
Mabey all 4 wheels of the ground :eek: dodgy i know ,then count wheel rotations when in gear front to rear ,Engage diff lock n see what happens ,,,get a friend to spot for you ,SAFETY FIRST ;)..then play doctor n nurse's with the stethoscope thingy;)... I mean on the landy:eek::oops::D:D..
 
Doesn't sound right to me either.
Don't know how to test these.
I'd hazard a guess that James Martin might but I don't know if he's been in for a while.

Does it drives normally if you then disengage the difflock?
Difflock on this should be vacuum engaged, could engaging it be affecting part of the braking circuit & putting the rear brakes on?

I also wonder if something has failed in the box but will still turn & engaging difflock causes it to jam. I have no idea what it might be but it may also explain your noise.

If the rear diff is seized then locking the centre one could cause a wheel to drag if turning on gravel?
 
Thank you everyone, every point is valid as it makes me think of something else to check so cheers. Well spoke to one if not the last of the LT95 gearbox repair specialist shops in the midlands and nothing shouted out to him (lovely chap). Check handbrake not to tight (to be honest it needs tightening), knackered diff, if it was going to go it would vibrate like f..k then it explodes. So I’ve gone for the 4 axle stands and running it in 1st gear, and with the diff lock on. Gave it a good wobble before starting to check solid and pointed it towards the field lol. With a stethoscope I checked the rear diff, silent, front same, transferbox just moving parts, gearbox same, bell housing very loud noise, I know some will be transferred by the v8. The thrust bearing is noisy until you depress it anyway, can a collapsed thrust bearing be the noise. A reminder, it’s silent as I drive off then as I get halfway round the block it starts and gets louder, also not happy to be out of gear to then change down until a slow speed once the noise starts. Could a thrust bearing be the noise and if it was failing could that effect then changing gear. Did I not grease everything enough perhaps when building it?
while sitting in it running off the ground, it didn’t have the same noise like a bag of marbles thrown in, I wondered if that was because it wasn’t under load as it would be driving along.
Sorted out the steering in the end I had to go for 6 degrees cranked arms
 

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