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TR4 O/D op. valve ball size

To: Nyberg Peter <Peter.Nyberg@lio.se>
Subject: TR4 O/D op. valve ball size
From: David Massey <105671.471@compuserve.com>
Date: Mon, 12 Jun 2000 19:40:23 -0400
Cc: "[unknown]" <triumphs@autox.team.net> charset=ISO-8859-1
Message text written by Nyberg Peter
> 

Hi list,
May 23, 1998 I bought a ' 62 TR4 which hadn't been on the road since ' 74.
The DPO had finnished step 1 in a total body off resto. i.e. body and
everything else detachable removed. There was plenty of rust, seized
engine (work of the elements) and lots of missing parts (!?!). Some of the
parts that came with the car came from other cars. I had only seen
TR4's on pictures so I didn't know what to look for.
Anyway, May 23, 2000 the car passed the gov. imposed inspection with flying
colors. CO was 0.3 you're allowed 5.5 on a +30 year old car. Except for
sand-
blasting chassis & tub and fixing the frozen calipers, I've done everything
myself.
It's definately not a concours winner - it's my first restoration and on a
limited
budget. And have I learnt some !
Now the reason I address the list - I can't get the O/D to work. When
reversing there's
a grinding noise in the box and when going forward the rev counter (and
engine) rev
quicker than the wheels (no, no clutch slip - it's transmission slip). The
solenoid is OK,
I've tried several lift heights on the operating valve and yes, there's oil
under pressure
when loosening the plug. However I measured the diameter of the valve (the
rod that
lifts the ball) and the diameter of the ball - they are both 1/4 ". The
illustration in
the workshop manual shows a ball seat and a ball that seems to be bigger
than the seat.
Anybody know the correct size of the ball?
At the moment the valve, ball, plunger and spring is removed and that
grinding noise
when in reverse is gone. The rev counter, engine speed and car speed is
syncronized.
Sorry about this long message. If I ever come back I keep the next one
shorter.
Cheers,
Peter Nyberg
Linkoping, Sweden
<

Peter,

It sounds to me that the valve is not functioning correctly and your
transmission is partially operating the pistons inside.  Could it be that
the ball is the wrong one and is fitting too far into the passage?  There
should be a portion of the solenoid travel that does nothing.  After this
you should feel the rod contact the ball and start to compress the spring
under the plug.  The solenoid should continue to lift the ball an
additional 1/32 of an inch (0.8 mm).  

At any rate you should be able to feel the transition from free movement to
compressing the spring.

Another thing is to check just how much pressure your pump is generating. 
The A-type overdrive should develop 500 to 600 PSI!  This means that jsut
because you have some pressure that you have enough.

I hope this is of help.

Dave Massey.
St. Louis, MO USA
57 TR3
71 TR6
80 TR8


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