James,
An indicator of the problem here may be the solution that Doug come up
with. His solution, which he details on his site, is to install a return
spring on the through out arm that insures the bearing doesn't run on the
pressure plate arms when not activated. This of course is a 'cure' for
worn components, but is indicative of the problem.
H.
-----Original Message-----
From: James H. Nazarian <microdoc@apk.net>
To: Chris Attias <cattias@cats.ucsc.edu>
Cc: MG Listserver <mgs@autox.team.net>; doug@mgbmga.com <doug@mgbmga.com>;
moss@mossmotors.com <moss@mossmotors.com>
Date: Wednesday, October 20, 1999 1:01 PM
Subject: Re: Roller Throwout Bearing
>Chris,
>
>I quote British Automotive:
>
> "Before you consider installing aftermarket ball/race type throw out
>bearings,
> be sure to read the following information. If you have already
installed
>this type
> of bearing, it is doomed to failure. Presently there are two styles of
>ball/race
> type bearings available:
>
> 1.- A black plastic housing type
> 2.- A steel housing type
>
> Both of these types of bearings suffer from premature "run-dry"
conditions
>and
> their failure is directly related to being in continual contact with
the
>clutch cover
> thrust pad. No.1 will self destruct in a very short time; No.2 will
>survive much
> longer and failure will not be as catastrophic."
>
>Why would a sealed, permanently lubricated roller bearing designed for
>continuous operation with load applied along the axis of rotation, run dry?
>Could it be defective? Or damaged during installation? If so, was it
returned
>to and examined by the manufacturer? If so, might we see their analysis or
>reply? If Doug's right, I've been driving several time bombs for the past
15
>years. Maybe Doug will share some of his exhaustive test data and methods
with
>us.
>
>Before I ask Mr. Moss to fly out to Ohio to help me change all these heavy
duty
>roller bearings back to the original graphite type, I think I need to see
some
>proof. Thanks in advance for enlightening us.
>
>Senior Doubting Thomas
>
>AKA Jim
>1960 MGA
>1974 MGB-GT
>and a pool of other octagonal delights
>
>Chris Attias wrote:
>
>> Peter C. wrote:
>> "A few quick thoughts. Roller bearing or carbon.... don't "ride" the
>> clutch. The only time that a clutch can become worn is when your foot is
on
>> the pedal. If you don't touch the pedal, the clutch wont wear."
>>
>> This seems to disagree with what I understood about the design of the
>> MGB Borg & Beck clutch assembly. See Doug Jackson's write-up on
>> clutch bearings @ www site:
>> http://www.mgbmga.com/tech/index.html
>>
>> While I realize Doug has some commercial interest in his development
>> of a fix for the problem he finds with roller bearings, he does
>> exhaustive research and shares his experimentation and research
>> freely...(No commercial interest disclaimer...)
>> Chris Attias
>> '64 MGB
>> '84 Alfa Romeo GTV-6
>
>
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