Thanks to all those who responded to my request for an "A" Type overdrive
with offers of parts, overdrive units and advice. I tried to reply to
everyone who responded but may have missed some, there were a lot of
e-mails. My apologies if I didn't get back to you. The FOT and its members
are amazing! Thanks to Mark J. Bradikis for making this possible.
I decided to "upgrade" to a TR4 transmission from our TR3 box and purchased
a "new" transmission and overdrive from John Esposito at Quatumechanics.
The transmission will have the larger layshaft bearings and the steel
bushings. John was very helpful with advice and good to work with. It got
to be that the cost of the repair parts for my old overdrive would have been
more than 50% of the cost of the "new" transmission and overdrive from John,
easy decision once I got to that point. We had an old TR4 non-overdrive
tranny from a rolling chassis we picked up that we can use for the exchange
with John. About the only really good parts from the old OD are the rear
housing, planet gears, accumulator and actuator pistons and some hardware.
The main shaft would have to be replaced also. At least now I have a
"dummy" main shaft for reassembling overdrives, that's about all the old one
is good for; lining up the splines.
After advice from a number of people, including Kas, I decided to stay with
the 22% OD with our 4.3 diff. It gives a good combination of a lot of punch
in 2nd and 3rd direct drive with a good overall ratio, 3.52, in 4th
overdrive, better than the 3.7 in the standard non-overdrive setup. And I
learned that there is a bit more to using the 28% in the TR than a simple
change of some gears.
I did learn a lot more about the OD. I had a nice phone conversation with
Jay Holekamp and Steve Yott drove up from southern Wisconsin in his
beautiful '67 TR4A to deliver one of his modified oil pumps, which will also
be a good upgrade to the engine, and gave me some more good information on
the OD. Jay put me on to the write up by Nelson Rydel on the Buckeye
Triumphs website which is really good for explaining the overdrive, its
operation, disassembly, reassembly and troubleshooting. I would recommend
it to anyone who wants to work on the overdrive. A great piece of technical
writing. Thanks to Irv Korey for putting me in touch with these two, both
great guys. The VTR write up by Larry Young and Sam Clark of Green County
Triumphs is also good and recommended.
It's been fun taking the OD apart and learning more about it. I think it
will now be part of the regular checkups on the engine and transmission to
disassemble the OD and check things over before I have another catastrophic
failure. I don't know if I could have prevented the last one but maybe I
could have limited the damage had I checked it earlier. The only thing I
didn't get removed was the pump body. I made the puller but it didn't want
to start to move very easily. I stopped before I busted something. I've
learned since that they pump body comes out really hard. It would seem
unless there is a problem with building up enough pressure that it might be
best just to leave well enough alone.
Again, thanks to everyone. We should get the new unit in
plenty of time to make the first race. And, it should be one less thing to
worry about on the track. I tend to drive like a mechanic anyway, thinking
too much about the car. Really can't help it, it's the engineer in meJ
Just takes me awhile to stop thinking about the car and just drive!!!
Tim
_______________________________________________
fot@autox.team.net
http://www.fot-racing.com
Donate: http://www.team.net/donate.html
Archive: http://www.team.net/archive
Forums: http://www.team.net/forums
|