An obvious thing to check is that the tranny is filled to the
correct level with fluid. Assuming that is the case, you can remove the
sump and check this filters to make sure they are not clogged. Make sure
you get both of them. There is a large screen immediately visible when
you open the sump, but there is also another filter assembly underneath
one of the screw in plugs in the sump. Clean both of them.
If that does not do it, I am afraid you are looking at pulling
the transmission for further work. Offering a swag, it sounds as though
your pump is not working, which can be a problem with the OD unit
itself, or a problem with the installation. The pump is driven by a cam
secured to the mainshaft with a woodruff key and a circlip. If the
woodruff key or the circlip is missing the pump cam will not spin and
the pump will not supply pressure to engage the OD. The pump piston has
some o-rings on it that may be shot causing low/no pressure.
My experience with "rebuilt" ODs is that the rebuilds are of the
ghetto variety: replace a few gaskets and o-rings. Only a few people
really take the time to do a full rebuild, which includes a new clutch.
A clutch alone costs $150, and so normally does not get replaced during
a budget rebuild. That has nothing to do with your problem, however.
So, check fluid level, sump filters, and then start thinking
about pulling the tranny.
I will send you an image separately that shows the two filters
in the sump, and the location of the pump and pump cam.
From: email@example.com [mailto:firstname.lastname@example.org] On
Behalf Of Mark J. Bradakis
Sent: June 22, 2006 5:29 PM
To: 'Triumph 6 Pack'
Subject: J type overdrive quandry
I do know a few things about Triumphs, but overdrives are not one of my
strongest areas. Perhaps someone on this list might have some helpful
I'm working on a car with a freshly rebuilt overdrive, it is claimed.
It doesn't work. Hooked up a pressure gauge, took a trip around the
Zero pressure in direct drive, 15 - 25 pounds with the solenoid engaged.
Seems like the pump non-return valve, I think. Pull that out, check it
shim the spring a bit. Now 20 pounds in direct drive, zero in
Something odd is going on here, suggestions on what to check next before
taking the whole unit out of the car?