To all,
I am taking a break this morning and couldn't help hit the list with an
unexpected discovery. I'm sure many of us have MG projects going this weekend.
I certainly have.
Yesterday, my son's '76 Midget just got a new left rear leaf spring. Couldn't
see any cracks in the old one, but it sure got weak suddenly. Never replaced
one of those before. A nice three hour job balancing many forces with
hydraulic jacks.
The main project is that I took the engine out of my '73 B two weeks ago.
First time it has been out of service in five years! There would normally be a
panic to get back in (it is my daily driver), but my wife has had some surgery
so I am driving the family car.
Anyway, The reason the engine and transmission are out is the clutch won't
completely disengage. I just knew it was the throw out bearing. I put one of
those roller versions on it in '94 because I just couldn't believe that carbon
style could hold up.
A couple of years later I was e-mailing Damit Dick (miss him) talking about
the roller bearing and got beseeched by everyone who was listerning that the
heavy duty roller bearing would fail sooner than the standard carbon one
because the "residual hydraulic pressure of the system would keep it in
contact with the pressure plate" unless a specal spring kit was also
installed. Well, VB sells the bearing, but no mention of the spring, so how
was I to know?
I lived in dread of the premature failure of that bearing for the past three
years. Finally, it happened.
This morning I installed the new clutch and standard throwout bearing. I was
amazed to see that the old bearing surface was not ground to bits and that the
bearing was still smooth and serviceable. I was also immediately concerned
that I had now overlooked something else!
I picked the old bearing up for another look 30 minutes later. Upon closer
examination, what I found was bizzare! The two pivot ears on that old bearing
were worn to less than half of their original diameter in the forward,
rearward direction. The normal diameter of those ears is about .550". The
measurement is now .260" Of all the ways that bearing could fail, the extreme
wear to those pivot ears is amazing considering the slight motion they go
through. I can also tell you I wiped a little grease on those ears when the
bearing was installed five years ago, as I did again today.
The loss of travel by this wear was not letting my clutch disengage
completely!
By-the-way, the fork appears to have no excessive wear at the adajcient points
(good, because I don't see them in anyone's catalog).
I guess that the bearing manufacturer didn't harden the surface of those ears
properly.
I may contact VB and let them know what happened, but obviously, the warrantee
is up.
Has anyone else seen this???
R. Johnson - Dallas
'73 MGB
'76 Midget
'79 Midget
'93 Maine Coon
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