<html><body>Simon-I did all of my test readings on the bench-transmission out of the car. I use an electric drill, in reverse, to drive the yoke and obtain the readings.<div><br></div><div>What you describe is a pressure issue in the accumulator. The car will not shift into OD with low pressure. It needs that high number to overcome the 8 springs which keep the cone clutch to the rear position (direct drive). Then as the pump builds up pressure, it is available when you flip the switch allowing the ball to seat in the valve.(providing that is seating properly-not bleeding down) That high pressure drives the two horizontal pistons forward, pushing against, and compressing, the 8 springs and allowing the cone clutch to now run to the front position, rotating the annulus and sun gear, thus effecting OD. </div><div><br></div><div>You do not have enough pressure to do that. The hot oil suggests lower viscosity, and loss of sealing of the O-rings and piston rings. So yes, I also think you are looking at a tear down and rebuild of the accumulator and oil pump parts. </div><div><br></div><div>Contact David at OD Spares and see if he concurs and order the necessary parts...sounds like its time for that. It would be nice to have that tunnel back in position and all working normal. Hank <br><br><div class="reply-new-signature"></div><p>-----------------------------------------</p>From: simon.lachlan@alexarevel.plus.com<br>To: gradea1@charter.net<br>Cc: <br>Sent: Wednesday August 4 2021 1:35:48AM<br>Subject: [Healeys] Overdrive pressure<br><br>
<div class="WordSection1">
<p class="MsoNormal"><span>Hank,</span></p>
<p class="MsoNormal"><span>Thank
you for that.</span></p>
<p class="MsoNormal"><span>Actually, it’s all gone
pear-shaped!</span></p>
<p class="MsoNormal"><span>I
discussed the OD pressure with Dave at ODSpares…..how high the
pressure went at 1500rpm with and without OD engaged and how long
it took for pressure to drop to zero. He said that re-seating the
ball had fixed it.</span></p>
<p class="MsoNormal"><span>I
took it out for a run down a local motorway and some country roads.
10 miles+/-. On the way to this particular pub- surprise – the OD
behaved well, better than for a while. Popped in and out very
briskly.</span></p>
<p class="MsoNormal"><span>I
only stayed for 20 minutes or so at the pub, by which time there
must have been a fair old heat transfer from gearbox and engine. It
did worse and worse on the way back. Pressure at 250psi in higher
revs and practically 0 at low revs. Paradoxically would click into
OD nicely but was back to slipping in/out at low revs.</span></p>
<p class="MsoNormal"><span>I’m
feeling my inner Basil Fawlty coning on. I’ll have to strip it down
after all.</span></p>
<p class="MsoNormal"><span>(It’s
a strange feeling…..sitting in the cab with the wheels off
the ground and letting out the clutch. Kept expecting the car to
surge through the workshop wall. Driving down the motorway without
the tunnel cover feels strange too. I do, so far, still have my
left hand. I do occasionally drive with left hand resting on tunnel
cover. Not yesterday!)</span></p>
<p class="MsoNormal"><span>Any
ideas would be appreciated,</span></p>
<p class="MsoNormal"><span>Simon</span></p>
<p class="MsoNormal"><span> </span></p>
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<div style="border:none;border-top:solid #E1E1E1 1pt;padding:3pt 0cm 0cm 0cm;">
<p class="MsoNormal"><b><span lang="en-us">From:</span></b>
<span lang="en-us">gradea1@charter.net
<gradea1@charter.net><br><b>Sent:</b> 03 August 2021 18:22<br><b>To:</b> 'simon.lachlan@alexarevel.plus.com'
<simon.lachlan@alexarevel.plus.com><br><b>Cc:</b> 'Healeys' <healeys@autox.team.net><br><b>Subject:</b> RE: [Healeys] Overdrive pressure</span></p>
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<p class="MsoNormal"> </p>
<p class="MsoNormal">Simon-glad you found the problem. That little
valve is the whole control of the pressure and release and dirt is
the main offender. </p>
<div>
<p class="MsoNormal"> </p>
</div>
<div>
<p class="MsoNormal">What I see on my gauge is pressure over
400-450, then when OD is off. a steady bleed down to 300,
200, 100 then in a couple of minutes, or sometimes a bit longer,
goes to 0. Its a "slow bleed". Fades as the oil flows down thru the
valve and that tiny hole. Enlarging it will make the bleed faster
and the plugging up with debris harder to achieve. They
recommend a 1MM hole if I remember the readings correctly, but its
a small drilling to allow oil to pass smoothly to the sump.
This is why you don't want 90W gear oil-its to "thick" to work with
the unit, and it also foams up in the annulus. Good 30W (or 20-50)
NON detergent oil is best to keep this process working. (detergents
also foam)</p>
</div>
<div>
<p class="MsoNormal"> </p>
</div>
<div>
<p class="MsoNormal" style="margin-bottom:12pt;">Possibly a little
oxidation or crud gets between the ball and the seat, and it then
needs a smack to reseat the fit. Small thing matter in this
scenario. We all need a smack, now and then, to get with the
program. Regards, Hank</p>
<p>-----------------------------------------</p>
<p class="MsoNormal" style="margin-bottom:12pt;">From: "Simon
Lachlan via Healeys"<br>
To: "Healeys"<br>
Cc:<br>
Sent: Monday August 2 2021 1:24:09PM<br>
Subject: [Healeys] Overdrive pressure</p>
<div>
<p class="MsoNormal">David,
Hank…..thank you for help and advice. Hank you were just about on
the money.</p>
<p class="MsoNormal"> </p>
<p class="MsoNormal">You’ll recall
that my OD was slipping in & out at low revs? Of course you do.</p>
<p class="MsoNormal">I bought a
gauge from ODSpares, excellent people/very helpful. (In retrospect,
I wonder how I’ve managed for so long without one).</p>
<p class="MsoNormal">Pressure
showed as well into the 470 to 490 range whilst OD was engaged at
+/- 1,500 rpm in 4<sup>th</sup>. Which is GOOD.</p>
<p class="MsoNormal">But, pressure
dropped to zero immediately upon disengaging and switching off.
Which is BAD.</p>
<p class="MsoNormal">The little
hole in the so-called “Valve operating” was/is clear.</p>
<p class="MsoNormal">I phoned Dave
Twigger at ODSpares who said that there was debris under the ball
on the seat there OR, if it was clear, then the ball needed
reseating.</p>
<p class="MsoNormal">So, I gave the
ball a few brisk taps and the pressure drop did slow a little up on
the next gauge test.</p>
<p class="MsoNormal">I gave it some
more taps and it improved somewhat again. Now takes about 30
seconds to get down to, say, 20psi and then loses pressure quite
slowly.</p>
<p class="MsoNormal"> </p>
<p class="MsoNormal">So:-</p>
<ol start="1" type="1"><li class="MsoListParagraph">How
hard can one “Tap” the ball? Not the easiest question to answer, I
do appreciate that. One man’s tap is another man’s wallop?</li>
</ol><p class="MsoListParagraph">I suspect I’ll have to repeat the
process……</p>
<ol start="2" type="1"><li class="MsoListParagraph">What
time duration is acceptable in operating terms for the pressure
drop? What am I aiming at?</li>
</ol><p class="MsoNormal" style="margin-left:18pt;">
</p>
<p class="MsoNormal" style="margin-left:18pt;">
Thanks, Simon</p>
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