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Driveshaft grief

Posted: 20 Aug 2009, 16:42
by CovKid
I mentioned in another thread that I've been getting a clonking noise from the back of the van at low speeds and when I take my foot off the throttle - again at low speeds. Two months ago I fitted new CV joints, meticulously packed with grease, carefully fitted, etc etc.

In the week I got so fed up with this noise I dropped in to see Merc Doctor and he took it for a spin. Then he jacked up each rear wheel, put it in drive and was pretty sure the right hand driveshaft (looking from rear) was noisy.

Anyway today I decided to replace the wheel bearings on the other side of the van and in the process removed the driveshaft on that side. The outer CV literally fell to bits leaving the centre part of the CV still on the shaft - not had chance to investigate what went on there, whether cage was shattered or whatever as its still covered in grease so replaced it with a reasonably good s/h one and set the disintegrated one aside. Took it for a spin. Noise still there so Merc Doctor's diagnosis correct but the point is these joints have a two year guarantee and seller said he's never had a new one go.

Thoughts? Bear in mind I'm ending up doing this job three flippin times and its not the most pleasant task to have to do, lets be honest. Yet to pull off side where noise is coming from but have to say there is no evidence of breakage or play if you grab hold of the shaft.

Getting might cheesed off.....

Re: Driveshaft grief

Posted: 20 Aug 2009, 16:55
by R0B
he would though wouldnt he :) (sorry but im old enough to be cynical)at least his guarantee ensures you get a refund.there not chinese chocolate ones are they...


seller said he's never had a new one go

Re: Driveshaft grief

Posted: 20 Aug 2009, 17:08
by CovKid
Update.

Best fill you in on this or we'll be going off on a tangent. I've just cleaned up the disentegrated one and theres nothing wrong with it. I suspect that at some point during my hot and bothered removal process, the joint ended up at an unhealthy angle, which as you know, will help it come apart rather well. Cleaned and everything in A1 condition. On this basis, I have no reason to think that the other side has any probs either. After all it passes the play test perfectly, even if i roll vehicle forward a fraction and try again. However this clonking/tapping persists when at low speeds. What the heck is it if its not driveshafts? Its most noticeable when slowing down for the lights. Not brakes as that has no effect on the noise. Its seems more prominent when engine not under load.

Re: Driveshaft grief

Posted: 20 Aug 2009, 18:43
by jaylo264
covkid , may be miles off but do you recall someone on here confusing cv noises with front gearbox mounting noises ? -- cannot remember who or what thread , but worth checking the integrity of your front mount rubber/metal ?
jaylo

Re: Driveshaft grief

Posted: 20 Aug 2009, 19:14
by CovKid
Yeah - I made a beeline for that in my explorations. All fine. To put the noise in context, its the sort that gives you that "Heck are we even going to make it" type noise. I'm loath to strip the other driveshaft when it checks out fine by feel and is only two months since I replaced it. Bolts are all tight.

Next week will try removing the drum on that side and work my way inwards towards gearbox, checking shock mountings as I go. As I've replaced wheel bearing and rechecked/regreased driveshaft on the other side, theres not much else I can think of that could make this noise. It had Merc Doctor foxed too although he did isolate which side it was. Its driving me potty as I'm not exactly a novice with VWs and its annoying when I can't get it to make the noise when its stationary. Just when you think you might know what it is - it isn't!

Re: Driveshaft grief

Posted: 20 Aug 2009, 21:47
by simony
might sound silly but are you sure its not the drum rubbing on the backing plate ? maybe only does it with the load of the van on it

Re: Driveshaft grief

Posted: 21 Aug 2009, 12:52
by CovKid
Drum that side will be first port of call. Chickenkoop has offered to come round and sit in the back whilst I take it round the block and see if he can locate it exactly. Does 'sound' driveshaft but seems in perfect order to be honest. Could be that a 'c' clip that hold the CVs on to the shaft has broken I suppose but would imagine that would have lead to immediate failure.

Re: Driveshaft grief

Posted: 23 Aug 2009, 21:15
by CovKid
This darned noise will be the death of me. Today checked drum (its contents) and the driveshaft - checks out ok. No evidence of play in driveshaft, wheel bearing fine (smooth and quiet). Decided to look at shocks starting from the front. Both removed, seemed in good order and no leaks, no worn bushes - gave them a lick of paint whilst out. All rubber mountings and bushes on front in good order. Barely a trace of rust on my chassis so its pleasant to get under. Front pads coming to end of service life I noticed (couple of months at most I'd guess) but nothing there that would produce the noise, besides it sounds mid-to-rear in origin and only when coming to a slow stop (brakes or no brakes) - clutch down tends to make it vanish but not a sound one would associate with say a noisy release bearing and doesn't seem to occur under load.

Tomorrow will get rear shocks off. After that I give up. I can't replicate the noise, can't find any duff bush or anything that I can think of I haven't checked. The only other thing left is to wait until whatever it is fails or MOT guy picks up something I've missed but I swear I've explored every nook and cranny, plus places I probably didn't need to. Levered things, pulled things, there is nothing I can find loose or would rub or clonk in the way this noise shows up. aaaaagh..... :?

I've taken almost everything apart - become quite familiar with running gear I can tell you.

Re: Driveshaft grief

Posted: 23 Aug 2009, 21:21
by ermie571
Ok, last resort...check under your seats for a loose bolt or the like rolling around.

years ago, on my velle I had a metallic knocking....found a rather large bolt rolling around next to the seat leg.......


Em
x

Re: Driveshaft grief

Posted: 23 Aug 2009, 21:24
by CovKid
It sounds relevant to wheel revolution though, rhythmic. Whatever it is, it won't do it with the wheels off the ground. Nothing touching tyres from the rear.

Re: Driveshaft grief

Posted: 24 Aug 2009, 00:41
by PoloSi
This is very school boy but a wheel wasn't loose?

Failing that mine always makes a noise when some cans of beer i've got on the floor roll back and forth :roll:

Re: Driveshaft grief

Posted: 24 Aug 2009, 07:41
by meggles
Had a similar sounding problem AFTER I replaced a CV joint on a mates van. Took joint off and turned it around. Looking at fitting instructions (very unclear and in sort of Japanese/English with a Chinese accent) it said something about a leading chamfered edge should face inwards. Anyway, after I turned it the other way round the noise stopped. All been well (touching wood) for a couple of thousand miles now!
Gotta be worth a try

Re: Driveshaft grief

Posted: 24 Aug 2009, 14:22
by CovKid
No, not that either. Spent another day on it. Doesn't appear to be getting any worse. Every axle taken apart now and finished off today by wire brushing small traces of surface rust on suspension arms and treating, just to gain something from all the work. Adjusted front wheel bearings a smidgen too, cleaned up shocks and painted them and bolted everything back up tight. Whatever it is doesn't appear to be evident in the running gear or drivetrain so best I can hope for is it vanishes on its own accord or gets so bad I simply can't miss it. Will be replacing shoes and pads in a month or so - perhaps that may reveal something missed, but for now I'm chalking it up as a Wolfsburg gremlin and not worrying about it. If nothing else I've given the running gear a welcome surprise in terms of a thorough inspection.

First time in 25 years I've even been beaten though.

Re: Driveshaft grief

Posted: 24 Aug 2009, 16:28
by R0B
just remembered.on my old van i had a loud clicking noise at slow speeds.turned out to be a nail in the rear tyre.prob not your problem.but it did drive me nuts for ages trying to work out what it was...

Re: Driveshaft grief

Posted: 24 Aug 2009, 18:32
by CovKid
The noise sounds exactly like a loose gear shift rod underneath with a repetitive clonk. Nearest I can describe. Cotton wool in ears may stop it though :D