I just had a nice experience with my A-H 3000 and want to pass it along. In
the process of doing a long overdue valve job, I discovered that the rocker
arm shaft was badly worn. A couple of you SOLers pointed me to:
Rocker Arm Specialist
Anderson, CA
916-378-1075
I sent them my rocker arm shaft and the 12 rocker arms for rebuild. Got them
back a couple of weeks later and everything looks brand new. $83 total incl.
shipping. Just the parts are $110 from Vicky Brit and you'd still owe a
machine shop for pressing out the old bushing, pressing in the new and then
drilling and reaming.
As an owner of five British cars over the years that use rocker arms, I can
vouch that this is a weak point on these engines. (Air cooled VW's have the
same problem but at least on them you can rotate the shaft 180 degrees and
wear out the other side before replacing). Apparently the steel shaft is too
soft. I went through two of these shafts on my '71 MGB before I found an
American made replacement that was made of a harder steel and is still going
strong. Once the shaft starts wearing you can no longer accurately adjust
the valves which can eventually lead to an exhaust valve not fully closing
which will lead to it's demise. As the wear continues, the lack of a tight
fit causes oil pressure to drop inside the rocker arm shaft and the resulting
irregular oil flow compounds the wear. Needless to say, all the while this is
happening, chunks of metal are poluting the oil.
It is hard to detect this problem as the damage is hidden under the rocker
arm bushing and it's on the bottom side of the shaft where you can't see it
even if you slide the rocker arm off of it's normal position. One should
check for this problem every 25,000 miles or so. To check: 1) loosen the
rocker arm adjusting screw quite a bit, enough to allow the ball at the
end of the adjusting screw to fully retract out of the socket on the top of
the push rod, 2) slide the rocker arm sideways off of its normal position and
3) feel for damage with your finger on the bottom side of the shaft. You'll
have to do this for all rocker arms as not all wear at the same rate. It's
common to see one very badly worn and the one next to it OK.M
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