Knocking noise coming from rear

[burnzdog]

Hi all,

Looking for for help with an issue. My Aircooled 2l has started making a knocking noise from the rear of the van. Doesn't start immediately but after driving for a few minutes it's starts to appear and progressively gets worse. I cant work out where it specifically is coming from but it is definitely coming from the rear. When accelerating is sounds more severe, but if I drop out of gear I can still hear it.

Any help appreciated.

[Ruralman]

Is it a wheel bearing?

[burnzdog]

I don't think so. It's quite a loud knocking noise. Doesnt sound like a bearing noise.

[CovKid]

CV joint and/or loose CV joint bolts. May just be hanging on and bolts about to snap. Check those as a priority.

[CJH]

If the knocking is related to wheel speed, it's probably a CV joint. I had the same on a journey home and was convinced I wasn't going to make it home. Wiggling the driveshafts at the roadside was enough to get rid of the noise temporarily though, and repacking the CV joints with grease seems to have fixed it since then.

https://club8090.co.uk/forum/viewtopic.php?f=37&t=146164" onclick="window.open(this.href);return false;

[burnzdog]

Thanks for feedback guys.


How easy is it to check if the problem is the cv boots? Can you advice on how I can check this?

[Dazco]

Another one for loose cv joints. Check your wheel nuts as well.

[kevtherev]

Thanks for feedback guys.


How easy is it to check if the problem is the cv boots? Can you advice on how I can check this?

get under the van grab the drive shaft try to push it up or pull it down, twist it forwards and backwards.
there should be no clicking or moving.

the shaft will move laterally, (in and out) that's normal.

*CV boots are the rubber covering on the CV, they should be intact with no splits.(MOT fail)

[burnzdog]

Thanks Kev, CV boots are intact, no splits, or signs of leakage. Will get underneath ang see if there's movement.

Thanks for feedback guys.


How easy is it to check if the problem is the cv boots? Can you advice on how I can check this?

get under the van grab the drive shaft try to push it up or pull it down, twist it forwards and backwards.
there should be no clicking or moving.

the shaft will move laterally, (in and out) that's normal.

*CV boots are the rubber covering on the CV, they should be intact with no splits.(MOT fail)

[CovKid]

Check outer CV joints very carefully - you'll need a torch. Not uncommon for bolts on outers to start working loose.

[burnzdog]

Been so cold I haven't had chance to get a decent look. I have managed to get under and check cranks. Tried last night (after almost crushing myself under the van!)

LHS & RHS drive shaft: With wheel on the ground. movement into and out of the hub/gearbox is easy, and the shafts move a couple of cm - I assume this is normal as the shafts have to move into and out of the box/hub in order to allow up and down movement. Tried moving the shaft up and down (i.e. vertical) and virtually no movement was possible; it was the same horizontally (i.e. front to back). I tried to rotate the drive shaft as it would when driving - no rotation possible. I reckon this side is fine - but maybe someone who knows these things can confirm or deny? Should I be able to rotate drive shaft? (sorry for if stupid question)

When checking bolts do I just peel back the CV boot? I do this for both ends on both sides?

Check outer CV joints very carefully - you'll need a torch. Not uncommon for bolts on outers to start working loose.

[andilad]

When checking bolts do I just peel back the CV boot? I do this for both ends on both sides?

The six bolts are hex headed and go around the outside, so follow the boot towards the gearbox, the boot ends in a metal edge joining to the round metal edge of the joint itself, the bolts go all around the edge of that metal edge. Yes check both the inner and outer, the outer is hard to see as it's inside the trailing arm, but with a torch some poking around you can see.

[CovKid]

If you have any doubt about condition of CV joints - replace them, lest you find yourself stranded - but certainly check security of bolts first. GKN Lobro joint kits are excellent. Non-brand ones should be avoided unless you like changing them every six months.

[burnzdog]

Thanks chaps.

I don't have to take the back wheels off to change joints do I?

[burnzdog]

Chaps these bolts are fastened hard. Any ideas on best tool and method to get these off?