[Healeys] Overdrive problem #1

Earl Kagna kags at shaw.ca
Sun Jun 6 09:24:20 MDT 2010


This happened to a friend of mine awhile back - overdrive wouldn't 
disengage, but if he wailed 5 - 10 minutes, upon starting the car again it 
was out of overdrive.  Turned out that there was a small bit of crud in the 
operating valve which was partially blocking the oil vent holes that allow 
the overdrive to realease.  This may not be your friends problem, although 
the symptoms are somewhat the same, and it's relatively easy to check with 
the trans/OD in the car , with the tunnel cover off.

Simply remove the operating valve plug, spring / plunger, ball, and the 
valve, and thoroughly inspect and clean the valve itself.  Work carefully - 
you don't want any damage to the ball or valve, otherwise it won't seat 
properly on re-assembly, and the overdrive may not go in.

It's worth a try because it's easy.  If no success, it's likely that the 
problem is internal, and things will have to come apart for diagnosis.

Let us know.

Earl Kagna
Victoria, B.C.
BT7 tri-carb

----- Original Message ----- 
From: <warthodson at aol.com>
To: <healeys at autox.team.net>
Sent: Sunday, June 06, 2010 6:57 AM
Subject: [Healeys] Overdrive problem #1

A friend's JB7 overdrive has stopped releasing (stopped going out of
overdrive). Electrically, everything is operating correctly. On rare 
it will release but 90% of the time it stays in overdrive. He knows to not
back up with it stuck in overdrive. When he stops the engine, we rock the 
backward & forward in gear until the overdrive releases with a bang. What is
the likely cause of this & are there any tests that we can perform of fixes 
can do with the overdrive/transmission in the car?
Gary Hodson

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