Date: Thu, 29 Apr 2021 11:21:18 -0700
Reply-To: Neil <musomuso@GMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Neil <musomuso@GMAIL.COM>
Subject: Re: Drums Rubbing
In-Reply-To: <MWHPR22MB012851FFE8E1A15FC3587CD2BA419@MWHPR22MB0128.namprd22.prod.outlook.com>
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A small amount of dirt or rust left on the hub flange face might cause
the back plates to sit a hair further outward, possibly at a slight
angle. During a full rear brake rebuild on my '81, I recall removing
old backing plate metal that had rust "welded" onto the flange face.
As a guess, if the lower shoe anchor wasn't seated all the way, that
could cause an alignment issue of drum to backing plate. But even
though the anchor pin is a tight fit to hub, you'd think the two bolts
would cinch that part down.
This image of new backing plate etc on my '81:
https://tinyurl.com/p2vbvfzz shows how the drum lip rubbed at the
plastic inspection hole bung and removed a fair amount of material.
But, that fitment issue may've been due to the plug length being
incorrect and/or drum design. I don't recall if the bung was OE but
drums were most likely Zimmerman.
Though that level of brake work was a first time effort on my part so
it's possible a slight flaw in my work caused the rubbing issue I saw.
That said, the brakes have worked fine for thousands of miles and the
amount of material erased at the plastic plug would indicate a part
design issue.
It sounds like your drum lips are quite close to each backing plate.
Given the large forces involved when making a sharp turn, any slight
"normal" play at bearings would allow the drums to rub.
Neil.
On 4/27/21, David Boan <dboan@outlook.com> wrote:
> Hello Vanagon Types
>
> I wrote a few days ago that my new drums were rubbing on my new backing
> plates. They did this constantly, driving straight or turning. I reported
> that I ground a 1/16" off the drum rim and problem solved. Well, not quite,
> they are quiet when driving straight but rub when making a sharp (90 degree
> or more) turn. The rubbing is only on the bottom half of the backing plate,
> maybe just the bottom 1/3.
>
> The brakes are working fine. The linings are also new and I also installed
> new wheel bearings at the same time (had a machine shop do this).
>
> I am thinking that the backing plate must be out of round for it to rub just
> the bottom of the plate. I hesitate to take any more material off the drum
> to try and fix it. I am considering just driving it for a while till I get
> the energy to replace the backing plates.
>
> I wonder why this happens just when turning. Does anyone have experience
> with this issue?
>
> Dave B
> Boise
> 85 Westy
>
--
Neil n
VE7TBN
1988 Westy 50º ABA swap: https://tinyurl.com/yap5hpwt
1981 Westy 15º ABA swap: https://tinyurl.com/y9n4xob8
VAG Gas Engine Swap Group <http://tinyurl.com/khalbay>
