Date: Wed, 21 Nov 2001 15:26:41 -0800
Reply-To: ID Workshop <idworkshop@HOME.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: ID Workshop <idworkshop@HOME.COM>
Subject: Re: Thump, Thump, Thump when turning????
In-Reply-To: <p04330103b821cb86d733@[128.111.74.60]>
Content-type: text/plain; charset="US-ASCII"
I thought I was the only one....I have had this thumping problem for over a
year.
My '86 Synchro made this dull thumping sound for the first quarter mile of
travel and then would go away. It sounds like the left rear wheel from where
I sit. It was definitely related to road speed, not engine speed. It was
defiantly related to ambient temperature. I did not notice the thumping in
the summer and it became apparent in the winter. The thumping took longer to
go away the colder the outside temperature was. The van had to sit for hours
for the noise to return. It sounded and felt like one of my tires was taking
a "set" while parked. I assumed that as the tire rolled and heated up, it
was returning to round. I basically just procrastinated fixing it and kept
driving......
Last spring I was returning to Portland, Oregon from a motorcycle road race
at Sears Point, In the SF Bay area, with my race bikes in tow. A small
driveline vibration became a van shaking shimmy over the next six hundred
miles. Three of my four tires had gone egg shaped.
The Tire shop replaced my tires at cost, and I was on my way again thinking
it was just a bad batch of tires. Well, when the temperature dropped in
October, thump thump thump. With four nearly new tires. I was now thinking
CV joint.
I have since replaced the engine with a TiiCo conversion and that mad no
difference, as I expected.
Last weekend I replaced my rattling rear Gabriel air shocks with OME shocks
and guess what? No more thump thump thump.
So, could it have been the old shocks? They don't rotate. Could the new
shocks be masking the problem more effectively?
I am relieved the Thump is gone, but I can't help but think it'll come back
to haunt me. I guess I'll have the CV's checked. They only have 40K on them
though (130K on the van).
Any thoughts?
Jon
> Dave,
>
> Based on the sound and conditions you describe, it sounds like a CV
> joint to me too.
> I would be more convinced if you said it was coming from the rear.
>
> I had almost exactly the symptoms you describe but was able to
> additionally identify the noise to be coming from the driver's side
> rear wheel area. I pulled that driveshaft and dissasembled the CV
> joints. Both looked pretty worn. I only had one new CV joint in my
> possession at the time so I gambled and replaced the outer CV joint
> which was marginally worse and just repacked and rebooted the inner
> joint. The noise went away so it was a good guess. Since then I've
> replaced the three remaining CV joints as preventative maintenance
> (this Westy has 168K on her).
>
> If you plan to do the work yourself and don't already know the whole
> procedure, I'd recommend Tom Carrington's website:
> http://volksweb.relitech.com/cvjoints.htm
>
> Good luck,
> Scott T.
> '85 Westy "Pearl"
> Santa Barbara, CA
>
>
>> My 82 has developed a strange tapping thumping sound that only happens when
>> going around curves at low speeds and seems to go away after driving a bit.
>> The sound seems to be related to the tires turning as it is very regular
>> and isn't engine rpm sensitive. I've been trying to see if it only happens
>> with power on or off but it usually only last a short bit and I haven't
>> found a spot to do wide slow turns continuously to try and test things. I
>> replaced the brake pads about three weeks ago and this started about a week
>> ago. Any ideas?
>>
>> Thanks,
>> Dave
