Clunk when lifting the clutch... any ideas?

[simihutch]

I'm really hoping someone can shed some light on this one...

I have an '82 2L Aircooled.

I've noticed over the last year it's started clunking when I lift the clutch to the bite on a rolling start. If the van is stationary and I lift the clutch, no clunk! But if i'm moving just slightly, when it bites, it clunks loudly. I can't tell precisely where it's coming from but somewhere in the transmission. 

It also clunks when I change gear. Just to add I have no issues with changing gear, no grinding or difficulty engaging gears.

I thought (as many would) it would be engine mounts so have changed all these and the gearbox mounts which has actually made the problem worse. I've also had all 4 new cv joints done recently.

If anyone has any thoughts, I'd really appreciate it as I've been scratching my head about this for ages. Ideally don't want to take the whole gearbox apart but if I could narrow it down to at least a certain area!

Thanks 

[Mocki]

I would say it must be internal to the gearbox if you have eliminated the engine mounts and the gearbox nose mount and you are sure there is no slack in the driveshaft CVs .
There isnt anything else in the drive train .
Maybe you need to get someone to look under whilst taking up the drive slack to see if anything else is moving ?

[silverbullet]

Loose hub nut or loose CV bolts?

[tobydog]

I've also had all 4 new cv joints done recently.

I'd still check the bolts/screws.

[simihutch]

I would say it must be internal to the gearbox if you have eliminated the engine mounts and the gearbox nose mount and you are sure there is no slack in the driveshaft CVs .
There isnt anything else in the drive train .
Maybe you need to get someone to look under whilst taking up the drive slack to see if anything else is moving ?

Thank you, yeah it's a puzzler. It's very noticeable loud clunk and I can hear it coming form back centre so it's somewhere in there. Definitely not CVs as they are new.

I guess it must be a bearing in either the clutch or gearbox as it's when the drive shaft and output shaft are reconnected whilst one is moving when it happens. However mechanically minded I am, gearboxes are a little beyond me sadly. Just don't want to put a new clutch in and realise it's not that either!

Ha, as it only happens when it's moving, it'll be a brave person that agrees to be run over to see if anything is moving underneath!

[simihutch]

I've also had all 4 new cv joints done recently.

I'd still check the bolts/screws.

Yeah, done that. Made sure they are all tight and can't feel any play in there.

[cobblers]

can of beans in a cupboard?

[Rosie n' Jim]

Whilst free wheeling during a gear change, the wheels are driving the gearbox. Then when the clutch is re-engaged the engine drives via the gearbox the wheels, so any slack will make a clunk. You could put the van in gear with one wheel lifted off the ground and hand brake off (other wheels securely chocked) and rotate the wheel back and forth. You'll be able to hear where the noise comes from and see what is moving, or not. 
Chock the other wheels though, play safely.

[Mocki]

can of beans in a cupboard?

Ha, that brings to mind an incident from many years ago, when a long term experienced owner had a random knocking noise he couldn’t track down, driving him nuts it was….. well after many people had given advice , non of which led to the solving of the issue , we were on a weekend camp , down at Apps Court in Londinium , a couple of us were trying to solve this issue , riding gently round the field listening and looking , umming and arging … turned out it was a 3/4 full glass bottle of Heinz ketchup rolling about in the bottom of a cupboard . Oh how we laughed !

[cobblers]

can of beans in a cupboard?

Ha, that brings to mind an incident from many years ago, when a long term experienced owner had a random knocking noise he couldn’t track down, driving him nuts it was….. well after many people had given advice , non of which led to the solving of the issue , we were on a weekend camp , down at Apps Court in Londinium , a couple of us were trying to solve this issue , riding gently round the field listening and looking , umming and arging … turned out it was a 3/4 full glass bottle of Heinz ketchup rolling about in the bottom of a cupboard . Oh how we laughed !

I had a 106 Rallye about 20 years ago. It had a nasty clunk on the front passenger side, I replaced *everything* - both wishbones, dampers, hubs, passenger side driveshaft, top mounts, even the steering rack! I was a student at the time so it absolutely skinted me. I could never stop this noise.

I took the engine out for other reasons, and while stood in the bay, I found a 1/2 drive snapon ratchet with a 36mm socket on it that had slid down the inner wing and was resting behind the headlight. 


 

[simihutch]

can of beans in a cupboard?

Ha ha, I have actually been caught out by an icepack left in the empty cool box! "For god's sake NOW what's banging"