I have taken my OD apart and replaced all of the following: accumulator
housing assemble, accumulator piston assembly with new O-ring,accumulator
spring, springs and balls for operating valve and the pump non-return
valve, O-ring for the piston assemblies and spring for the oil pump and
the eight clutch springs( most of the springs looked OK, but I didn't
want to go back into this unit if I didn't have to). I did not go into
the
tail section as all of the bearings seemed to be Ok, as did the sliding
clutch assembly and other components. I am ready to put this thing
together and give it a try, except for...
Some time back I read the articles that was posted on the
buckeyetriumphs web site about the A type overdrive manufactured by
Laycock-de-Normanville. The author, Nelson Riedel, was discussing the
overdrives
that came in the Triumph's( through 1972). He described how they worked,
the disassembly , the replacement of parts, testing the OD prior to final
assembly of the main case and adapter plate, Final assembly and testing
prior to installing in the car. I think it is a very good article and
provided me with in site in working on my Overdrive and I pretty much
followed his instructions. He did a preliminary test prior to
installing the OD on the gearbox. He ran a test using compressed air to
make sure the values and pistons were working. An adapter(air fitting)
with 1/4 pipe threads on one end and a plug for the operating valve (old
Operating valve with a 3/32"hole drill through the plug)on the other was
made and installed into the operating valve opening, with the
spring,plunger and ball in place. He installed the eight springs, a
dummy main shaft and bolted a wooden adapter plate to the housing. A air
line was connected and a 100 lbs of pressure was applied. When the lever
below the operating valve plug was pushed down there was a audible clunk
as the clutch shifted into OD. I did all of this. I applied about 110
lbs of pressure to the operating valve and
pushed down on the lever but the clutch did not shift into OD. I could
hear air escaping from the unit, but not a lot. I took the operating
valve apart and used the old ball to tap on the valve opening and
remounted with a new ball. I took the non-return valve apart and did the
same thing. Tried the air again and got the same results. I took the
large brass oil drain off and could feel air coming out of the bottom of
the oil pump. I had removed the oil pump to change the spring( I wish
that I had waited on this and did the air test first, it may have told me
if the removal and replacement of the oil pump had created the problem)
and it was well stuck in the case and was very tight when I reinstalled.
I loosened the nuts on my wooden adapter plate as Mr. Riedel suggested,
but had
to loosen them to where I had about 7/16" gap between the wooden adapter
plate and casting before it shifted into OD. I sent Mr. Riedel a
e-mail asking for his advise but have not gotten a reply and probably
won't.
I am not sure what to do now. I'm not sure if there should be any
air leak at all and if not , could the air be escaping through the pump
due to wear? How do you tell if the oil pump should be replaced? Is there
a better way to seat the balls in the oil pump opening and the operating
valve? Can you suggest any other course of action?
Your help would be appreciated
J.E. "Sam" Austin
|