rear end of the beetle making weird noises

Pauld Officially Full-On Dubber

204 posts · joined Sep 2008 · 30 Jun 2009, 10:41 am

#721460

hey guys at the beginning of last week my bug started making noises, the noise starts at about 30ks, seems to be coming from the rear, there is a fairly consistant knock which im not sure about so what in the back can make noises

Bookwus Seriously Crusin Dubber

120 posts · joined Aug 2007 · 30 Jun 2009, 11:34 am

#721461

Hiya Paul,

Does this sound sound as if it might be rotational in nature?

Mike

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Sides Veteran Volks Folk

2,220 posts · joined May 2007 · 30 Jun 2009, 3:22 pm

#721485

Does the knock change with engine RPM - as in is it faster/louder in 3rd gear than it is when you change to 4th ?
Does the noise stop if you pop the clutch when the car is already up to speed, or does it stay the same ? What about if you put the car in neutral and let the clutch out ?

Those things will help narrow whether its engine or trans or wheel/brake related.

Things I've heard make knocking noises from the rear of a bug:
- bad rear wheel bearings
- cracked and/or warped brake drum
- brake lining separated from shoe (inside the drum)
- loose castellated (axle) nut
- loose wheel nuts
- cracked wheel around one nut
- clagged out CV's on an IRS
- loose gen pulley
- bent fan
- J pipe leak on one cylinder only (weird sometimes how much a phutt can sound like a knock)

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68AutoBug Beetle Restorer - Experience over 138\% - YIKES --

11,654 posts · joined Aug 2002 · 30 Jun 2009, 8:10 pm

#721537

Pauld wrote:hey guys at the beginning of last week my bug started making noises, the noise starts at about 30ks, seems to be coming from the rear, there is a fairly consistant knock which im not sure about so what in the back can make noises

Hi Paul
If You have a super with IRS rear end its probably a Constant Velocity joint which is dry of grease and probably worn.. hence the knocking...

filling it up completely with Lithium based Moly grease will probably stop any further wear and the noise...
if it hasn't gone too far... the wear/grooves that is...

If the large axle nut wasn;t done up to over 300ft lbs
which means jumping on 2 metres of pipe on a breaker bar
then the splines wear on the brake drum and it will eventually stop driving the wheel when all the splines have worn thru..

Have you checked the wheel nuts??
and other things that Dave mentioned??

whatever it is, isn't going to get any better...
and can eventually cost you more money if You don't get it fixed... ASAP..

I don't think its an easy thing like brake pins and clips as they would make a noise all the time the car was moving..

I don't think its an engine thing...
so thats good news...

cheers

LEE

- Helping keep Air Cooled VWs on the road - location: SCONE in the Upper Hunter Valley - Northern NSW 320 kms NNW of SYDNEY---

Pauld Officially Full-On Dubber

204 posts · joined Sep 2008 · 30 Jun 2009, 9:26 pm

#721552

thanks guys il look at all of that, its got a swing axle rear and will be putting it up in the air on the weekend and running it through the gears see what iv got im not driving the car at all untill i sort it out

Pauld Officially Full-On Dubber

204 posts · joined Sep 2008 · 2 Jul 2009, 7:58 pm

#721900

Its all good just a rear wheel bearing, does any one have the part number of the aftermarket replacements at all? Is it a difficult thing to do at all?

68AutoBug Beetle Restorer - Experience over 138\% - YIKES --

11,654 posts · joined Aug 2002 · 2 Jul 2009, 11:23 pm

#721956

Pauld wrote:Its all good just a rear wheel bearing, does any one have the part number of the aftermarket replacements at all? Is it a difficult thing to do at all?

Hi
I'd try getting one or two from a VW shop as they are probably going to be cheaper than a bearing shop...

check out CIP1 to see if you need one or two...
and whether they are the same...

IRS have two bearings the same size but totally different bearings ... one cheap one.. 6206 or 6306 ball bearing
and one expensive one NU206 or NU306.. roller bearing

this is from memory... as I've never replaced any...

cheers

LEE

- Helping keep Air Cooled VWs on the road - location: SCONE in the Upper Hunter Valley - Northern NSW 320 kms NNW of SYDNEY---

Pauld Officially Full-On Dubber

204 posts · joined Sep 2008 · 3 Jul 2009, 9:39 pm

#722140

cbc for a 6306 sealed bearing and a double lip tc seal has to be the go as nobody carries spares up here for them so will have a go tomorrow do i need a puller at all? Or do they pretty much sit in?