[TR] Transmission internal pressure question - Resolved!

Mark Hooper mhooper at digiscreen.ca
Tue May 4 16:07:24 MDT 2010


A huge thanks to the listers who contributed their experience with the leaky
overdrive transmission situation.

In the end, I determined that my unit had been assembled with a shift tower
lacking the vent hole. I gather that the tower was originally from a 4-speed
transmission where the vent is in the rear extension. So, following an image
from Randall and corroborating input from everybody, I drilled an appropriate
1/8" hole in the tower into the very front end of the reverse shift rod
passageway.

Yesterday I went for a drive up the highway and small roads; a good 1/2 hour
run with lots of shifting and overdrive on and off. At the end barely a single
drop of oil escaped from the unit where it had been leaking quite copiously
from the shift o-rings and position switches before. The one small drop that
did get out was probably just leftover from the last mess.

So, barring some rather strange situation, this truly seems to have been the
major fix over the perennial nasty problem with my LBC.

Thanks again for the fantastic help! I would simply never have found that tiny
hole (or lack of same) without very specific instructions.

Mark Hooper
1972 TR6





-----Original Message-----
From: triumphs-bounces at autox.team.net [mailto:triumphs-bounces at autox.team.net]
On Behalf Of Jim Muller
Sent: May 2, 2010 6:40 PM
To: Triumph Mail List
Subject: Re: [TR] Transmission internal pressure question

On 2 May 2010 at 10:31, Mark Hooper wrote:

> Thanks for the replies. I have been all over the shift tower on
> my J-type and my A-type units. I do not see a vent hole.

When you guys get it straightened out (and perhaps you have already
and I just don't have the brain cells left to comprehend), let me
know.  My Spitfire's gearbox drips oil on the exhaust pipe and the
culprit is oil collecting on the very top of the gearbox.  I ask
myself how it gets up there.  The top plate has a vent, I think
that's what it is, shielded on the inside of the box and with what
looks like a slightly broken plastic plug.  If the shield is meant to
keep oil from forcing its way up through that hole, it isn't working.

--
Jim Muller
jimmuller at rcn.com
'80 Spitfire, '70 GT6+


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