<VV> Need Help - 69 Front Suspension Settings

[Jay Maechtlen]

On 12/22/2014 7:17 PM, Frank DuVal via VirtualVairs wrote:
> Bill, I am not picking on you , I ask this question every time I hear 
> or read the phrase "turned the drums".
>
> Why did you turn the brake drums? They can only be turned until the 
> minimum diameter is reached, then they are no good. Back in the 60s 
> every shop seemed to turn drums with every brake shoe replacement. 
> Even undamaged and new drums! They sold a lot of needlessly replaced 
> brake drums... I have not turned a drum in 20 years.
>

In the old days...
it was taught - perhaps as a safety measure. The average shop/mechanic 
didn't have a good way to check for out-of-round, or other possible 
problems.
Some drums had hard spots /bad metallurgy. I'm not sure that turning 
them would have helped, anyway.
It was written that a drum could wear to a bellmouth or barrel shape. In 
theory, a non-cylindrical drum wouldn't stop the same one that was 
perfectly cylindrical. Also, it would take a while for the shoes to wear 
down to match the drum surface.
A drum that's been in service has a smooth surface. if the arc of the 
shoes doesn't match the drum size, only part of the shoe will contact 
the drum. That could overheat the lining at the contact point, damaging it.
In any case, if the brakes aren't the same between right and left, you 
can get pulling or other funny behaviour.
If you're doing work on a production basis, you don't want comebacks. 
Turning drums is a way to improve your odds of a good job, and you get 
to charge the customer for it.

For us cheap so-and-sos, if it's not obviously our of round or horribly 
worn, we might just throw linings on it and run it.

-- 
Jay Maechtlen
SoCal
'61 2-dr modified w/fiberglass skin,
transverse 3.8 Buick V6 TH440T4 trans

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