Rear diff knocking - cause?

[Sirocco]

It seems that my rear diff is making a big clunk on taking up drive and in 2nd mostly. Angry gear changes from 5th to 4th up hills also make it do it but not too often.

So the props looks fine as do the halfshafts. oil changed fairly recently and still looks fresh. Diff was bought 2nd hand (along with the front) fitted with a Truetrac installed and fully re-furbished by a reputable company.

I'm going to drop the oil tomorrow If I get time and can find somewhere to do it to see if there are any bits in it.

Drives fine, but i'm worried about the knocking.

Currently in Stavropol, Russia on my way east (but if this thing goes tits up we will be heading west!)

Any pointers?

G

[landroversforever]

Could it be the A frame ball joint clunking as you take up drive G?

[steve b]

Yep I'd look there first, then Aframe arms to chassis bushes , then trailng arm to axle bushs/bolts

If none of those then drain the oil and look for planet gear teeth , also worn splines in the drive members/outer halfshaft ends can give

a clunk on-off-on throttle

good luck and happy trails- loved the pics you posted the other day

cheers

Steveb

[Jode]

I'd also suspect the A-frame ball joint. Worn splines on the half-shafts/diff centre will clause clunk, however a truetrac is said to run smoother than the standard diff by virtue of its design.

[Sirocco]

Thanks for the replies guys. I forgot to add that the A frame seemed fine. It was replaced before we left along with Superpro bushes all around. When it was on the lift at the dealer it sounded like it was coming from the Diff and the arms didn't seem to move. They said it probably wasn't a problem (in Russian) but I wonder if they were shurking work as it was the end of the day.

I may get a chance to look tonight but I doubt it as we have been invited out to someone's house for food again!

Will keep you updated as I do need some advice on this. But worried about going further east if my Diff is going to explode. I suppose towing a sankey don't help much...

G

[Sirocco]

I popped the 'X-Eng' diff plug out this morning and there was a slight bit of metal sludge but nothing big.

Soooo, does that mean its ok? Could the Truetrac be at fault?

Checked arms, A frame again, the halfshafts I checked previously looked ok and all drive bolts were fine.

My other suspicion may be something at the other end behind the handbrake drum in the gearbox, but I have never fiddled with anything in there so don't know much about it.

I should also add that Its not only a clunk, its a bit of a shudder too. Ie. Its not a small knock.

G

[steve200TDi]

Hi,

Have you checked the propshaft for wear, including the sliding joint. I remember once I had horrendous vibration and it turned out to be the sliding joint had seized up.

Also maybe, go for a short drive without the rar propshaft on to see if the noise disapears, but it may not be advisable if you have a trailer and a fully laden 90.

Steve

[cackshifter]

Shudder- could it be the handbrake shoes grabbing at the drum, you could try just backing of the adjuster pro tem and see if that makes it go away?

[steve b]

That sounds very likely specially if there is any oil on the HB shoes , as it drags then releases

then drags again it sounds terminally terrible

cheers

Steveb

[Eightpot]

Noticed some vibration and knocking on my 110 this week, particularly on overrun at highway speeds. Has been difficult to diagnose, but rocking the back wheel like checking for wheel bearing play gave it away, was easy to hear the worn inner splines of the drive shaft knocking in the diff.