Re: [DML] Re: Clunk (not TAB or axles)

[Peter Lucas <lucas@xxxx>]

I, too, have been plagued with rear-end clunks since the day I 
test-drove #6703. It is by far the most annoying problem on my 
vehicle--it really detracts from an otherwise amazingly pleasant driving 
experience. I have read every word ever posted on this topic and spoken 
to many people and followed all the standard advice without success. I 
do not believe that *anybody* really understands what is going on. Rob 
Grady told me that he once solved a clunking rear-end by replacing the 
rear bearings, but that the problem came back in a year.

Part of the problem no doubt stems from the fact that there are multiple 
causes, so everybody's advice has a kernel of truth. For the record, 
here is an annotated list of all the theories that I am aware of:

1)	Objects sliding around in trunk (or the jack storage space in front 
of the trunk).
Comment: This is real. Don't underestimate it. It is often 
surprisingly difficult to localize sounds in a car--even front/rear can 
be confusing. Hint: Stick some industrial-sized velcro on the bottom of 
your tool box and it will grip the carpet of the trunk and stop sliding 
around.

2)	Battery not secure.
Comment: Maybe, but I'm not convinced that it is all that easy to 
tip or slide the heavy battery around. Can anybody report first-hand 
that this was the source of their clunk? In any event, tying down your 
battery is good hygiene, so why risk it?

3)	TAB problems.
Comment: Almost certainly a real cause of rear-end noise. There 
have been first-hand reports to that effect. Not clear to me that it 
could easily account for the characteristic "left turn/right turn" 
alternation that many of us experience. I am about to install Toby 
Tabs, so we'll see...

4)	Loose body bolts.
Comment: There are also first-hand reports of tightening body bolts 
curing clunks. Didn't help in my case, although I have not done the 
hard-to-get-at right-rear bolt. If all else fails, I will try that, but 
I am pretty sure I hear clunks on both sides and the everything on the 
left is definitely tight.

5)	C/V Joint problems.
Comment: It is often suggested that bad or poorly lubricated C/V 
joints cause the drive shafts to hang up on turns. It is true that if 
you slide the shafts back and forth by hand you can make a sound that 
kind of resembles the accursed clunk, but I am skeptical. I have not 
seen first-hand reports that C/V work has actually cured the problem (I 
filter out "well, seemed to help some" comments as wishful thinking). In 
any event, inspecting and repacking the C/V joints didn't help in my 
case.

6)	Bad rear bearings or rear hub problems.
Comment: I have encountered few hard facts on this alternative, 
beyond the aforementioned discussion with Rob. I consider this a likely 
cause, just because I can't think of anything else. There was a vague 
article circulating a few years ago involving spraying WD40 into this 
area, but I could never make it work. Can anyone elaborate on this 
theory? If my new TABs don't help (and I don't think they will), new 
bearings will be my last resort.

Anybody who has anything to add to this list, please do so. This is 
clearly a widespread problem, and annoying as hell. It would be great 
to finally nail it.

--Pete Lucas
VIN #06703

On Thursday, May 23, 2002, at 01:20 AM, Walter Coe wrote:

> > As I recall, there was
> > quite a bit of information exchanged while Walt worked through his
> > noise.
>
> Nope, my car still clunks. I haven't found the problem. I know that my
> battery is loose because a previous liquid acid battery leaked and 
> rotted
> the strap apart. But the clunks that I hear sound more like they are
> echoing through the frame. I know my TABs are fine (although they are
> pre-Toby technology). The next thing to check are my body bolts, but I
> haven't had the time to get that deep into it.
>
> Walt