<div dir="ltr"><div class="gmail_default" style="font-family:arial,sans-serif;font-size:small"><br></div><div class="gmail_default" style="font-family:arial,sans-serif;font-size:small">
<i>Wouldn't opening up an O/D with 500psi be kind of messy?
</i></div><div class="gmail_default" style="font-family:arial,sans-serif;font-size:small">Lots of pressure but actually very little volume of oil involved.</div><div class="gmail_default" style="font-family:arial,sans-serif;font-size:small"><br></div><div class="gmail_default" style="font-family:arial,sans-serif;font-size:small">M<br></div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Mon, Apr 18, 2022 at 11:25 AM Bob Spidell <<a href="mailto:bspidell@comcast.net">bspidell@comcast.net</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
<div>
Wouldn't opening up an O/D with 500psi be kind of messy?<br>
<br>
<div>On 4/18/2022 8:03 AM, Roger Grace
wrote:<br>
</div>
<blockquote type="cite">
<div dir="ltr">
<div>To confirm Michae's analysis, consider:</div>
<div> remove ball, spring and plunger<br>
</div>
<div> remove the valve push rod and inspect - I use a piece of
steel wire of appropriate thickness to pry out.<br>
</div>
<div> replace the push rod - it should go in smoothly<br>
</div>
<div> insert the wire again and push down gently; with your
other hand operate the cam and you should feel the operating
rod move up and down on the cam.<br>
</div>
<div> if not MS is correct and the pin/peg has failed....</div>
<div> of course it could also be the cotter pin that goes
through the setting lever - but less likely IMO<br>
</div>
<div>BTW I have found that my OD (O rings) holds 400 psi for
several days.</div>
<div>rg<br>
</div>
<div><br>
</div>
<div><br>
</div>
</div>
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<div dir="ltr" class="gmail_attr">On Sun, Apr 17, 2022 at 3:21
PM Simon Lachlan via Healeys <<a href="mailto:healeys@autox.team.net" target="_blank">healeys@autox.team.net</a>>
wrote:<br>
</div>
<blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
<div lang="EN-GB">
<div>
<p class="MsoNormal"><span>That’s the one I’ve got. I did
get an increase in pressure. No question about that.</span></p>
<p class="MsoNormal"><span>I talked to Dave at OD Spares
with regard to the various accumulators out there at
the moment. I don’t recall exactly but he supplies all
of them to his customers and, I think, to the
suppliers.</span></p>
<p class="MsoNormal"><span>Simon</span></p>
<p class="MsoNormal"><span> </span></p>
<div>
<div style="border-color:rgb(225,225,225) currentcolor currentcolor;border-style:solid none none;border-width:1pt medium medium;padding:3pt 0cm 0cm">
<p class="MsoNormal"><b><span lang="EN-US">From:</span></b><span lang="EN-US"> Healeys <<a href="mailto:healeys-bounces@autox.team.net" target="_blank">healeys-bounces@autox.team.net</a>>
<b>On Behalf Of </b>Bob Spidell<br>
<b>Sent:</b> 17 April 2022 23:06<br>
<b>To:</b> Michael Salter <<a href="mailto:michaelsalter@gmail.com" target="_blank">michaelsalter@gmail.com</a>><br>
<b>Cc:</b> <a href="mailto:healeys@autox.team.net" target="_blank">healeys@autox.team.net</a><br>
<b>Subject:</b> Re: [Healeys] Overdrive pressure
not releasing.</span></p>
</div>
</div>
<p class="MsoNormal"> </p>
<p class="MsoNormal" style="margin-bottom:12pt">AH Spares
has an accumulator and piston which uses an O-ring. It
appears the pressure relief hole is chamfered:<br>
<br>
<a href="https://www.ahspares.co.uk/austin-healey/performance-parts/gearbox-overdrive/o-ring-conversion-accumulator-piston.aspx" target="_blank">https://www.ahspares.co.uk/austin-healey/performance-parts/gearbox-overdrive/o-ring-conversion-accumulator-piston.aspx</a><br>
<br>
</p>
<div>
<p class="MsoNormal">On 4/17/2022 12:03 PM, Michael
Salter wrote:</p>
</div>
<blockquote style="margin-top:5pt;margin-bottom:5pt">
<div>
<p class="MsoNormal">Actually Bob I've never used an
"O" ringed accumulator. </p>
<div>
<p class="MsoNormal">I spent a little time many
years back looking into using "O" rings on the
accumulator but couldn't resolve the issue of the
ring being chaffed when passing over the radial
drillings in the accumulator body. </p>
</div>
<div>
<p class="MsoNormal">Does anyone know how that has
been solved?</p>
</div>
<div>
<p class="MsoNormal"> </p>
</div>
<div>
<p class="MsoNormal">M</p>
</div>
</div>
<p class="MsoNormal"> </p>
<div>
<div>
<p class="MsoNormal">On Sun., Apr. 17, 2022, 2:49
p.m. Bob Spidell, <<a href="mailto:bspidell@comcast.net" target="_blank">bspidell@comcast.net</a>>
wrote:</p>
</div>
<blockquote style="border-color:currentcolor currentcolor currentcolor rgb(204,204,204);border-style:none none none solid;border-width:medium medium medium 1pt;padding:0cm 0cm 0cm 6pt;margin-left:4.8pt;margin-right:0cm">
<div>
<p class="MsoNormal" style="margin-bottom:12pt">Michael,
<br>
<br>
Sounds like you're implying the O-ringed
accumulator is superior to the metal ring (OEM)
type? Wish I'd known about it when I rebuilt my
O/D (I bought the DWM 'uprated' accumulator).<br>
<br>
I'll throw out another, very unlikely, potential
cause: the cone clutch could be stuck together.
I've heard of this happening, but have never
experienced it my self--nor has anyone I
know--but it's theoretically possible (esp. if
the clutch is excessively worn). Could this be
the reason the manual is adamant about replacing
the 8 strong springs, of two lengths, that
oppose the operating pistons on overhaul,
regardless if they still seem robust?<br>
<br>
</p>
<div>
<p class="MsoNormal">On 4/17/2022 9:31 AM,
Michael Salter via Healeys wrote:</p>
</div>
<blockquote style="margin-top:5pt;margin-bottom:5pt">
<div>
<div>
<p class="MsoNormal"><span style="font-size:12pt;font-family:"Arial",sans-serif">Simon,</span></p>
</div>
<div>
<p class="MsoNormal"><span style="font-size:12pt;font-family:"Arial",sans-serif">Based
upon your synopsis I conclude that the
operating valve is NOT opening when
either the solenoid lever or the setting
lever is being moved to the position
where the operating valve ball would
normally be lifted off its seat.</span></p>
</div>
<div>
<p class="MsoNormal"><span style="font-size:12pt;font-family:"Arial",sans-serif">This
conclusion is based upon your discovery
that the pressure in the accumulator, as
indicated on the gauge, does not leak
away overnight.</span></p>
</div>
<div>
<p class="MsoNormal"><span style="font-size:12pt;font-family:"Arial",sans-serif">There
is a small clearance between the
operating valve push rod and the
overdrive housing. If the operating
valve ball was indeed lifted off its
seat all the oil in the accumulator
would, over time, leak past the
operating rod thus discharge the
accumulator. </span></p>
</div>
<div>
<p class="MsoNormal"><span style="font-size:12pt;font-family:"Arial",sans-serif">This
process would indeed take some time but
would certainly completely relieve most,
if not all the residual accumulator
pressure overnight.</span></p>
</div>
<div>
<p class="MsoNormal"><span style="font-size:12pt;font-family:"Arial",sans-serif">If
however the operating valve ball is
still in contact with its seat (i.e. not
being lifted) the oil pressure would not
reach the small clearance between the
valve push rod and the housing and,
other than past the accumulator rings
there is nowhere for that pressure to be
relieved. </span></p>
</div>
<div>
<p class="MsoNormal"><span style="font-size:12pt;font-family:"Arial",sans-serif">I
would presume that Overdrive Spares
installed an accumulator with an "O"
ring rather than the original cast iron
rings. If the original type accumulator
piston was still fitted, oil would seep
past the cast iron rings to relieve the
pressure, albeit very slowly, and again
the accumulator pressure would be
discharged overnight..</span></p>
</div>
<div>
<p class="MsoNormal"><span style="font-size:12pt;font-family:"Arial",sans-serif">The
cam on the operating shaft, the one
which lifts the operating valve push rod
and thus the operating valve ball, is
locked to the shaft with a small taper
pin. I would guess that the taper pin
has either fallen out or sheared. </span></p>
</div>
<div>
<p class="MsoNormal"><span style="font-size:12pt;font-family:"Arial",sans-serif">Bad
news is that this pin cannot be accessed
without removing and disassembling the
overdrive.</span></p>
</div>
<div>
<p class="MsoNormal"><span style="font-size:12pt;font-family:"Arial",sans-serif"> </span></p>
</div>
<div>
<p class="MsoNormal"><span style="font-size:12pt;font-family:"Arial",sans-serif">M</span></p>
</div>
</div>
<p class="MsoNormal"> </p>
<div>
<div>
<p class="MsoNormal">On Sat, Apr 16, 2022 at
1:19 PM Simon Lachlan via Healeys <<a href="mailto:healeys@autox.team.net" target="_blank">healeys@autox.team.net</a>>
wrote:</p>
</div>
<blockquote style="border-color:currentcolor currentcolor currentcolor rgb(204,204,204);border-style:none none none solid;border-width:medium medium medium 1pt;padding:0cm 0cm 0cm 6pt;margin-left:4.8pt;margin-right:0cm">
<div>
<div>
<p class="MsoNormal">My OD is driving me
mad and I definitely need some
inspired advice. A bit of background
first. I’ll try to lay out all the
facts in a logical sequence. (I’m
increasingly reluctant to link ODs
with logic!)</p>
<ol type="1" start="1">
<li class="MsoNormal">I’d say that the
OD has done +/- 15k miles since a
total rebuild by Overdrive Spares
here in UK.</li>
<li class="MsoNormal">The OD had
issues before Christmas (21) and was
sorted out by OD Spares. The
accumulator was uprated and pressure
issues sorted.</li>
<li class="MsoNormal">OD functioned
100% on the few times I’d been able
to take it out since then until..</li>
<li class="MsoNormal">One day, the OD
stopped functioning.</li>
<li class="MsoNormal">I checked the
electrics. All fine there so I
delved a bit deeper.</li>
<li class="MsoNormal">It had fried its
solenoid which I replaced. But…</li>
<li class="MsoNormal">That did not fix
the problem so…</li>
<li class="MsoNormal">I decided that
the operating valve’s adjustment
might be off so..</li>
<li class="MsoNormal">I bought a dial
gauge and hoped to sort it out
precisely rather than by “feel”,
which I lack in this area.</li>
<li class="MsoNormal">Prior to using
the gauge I decided to see if the OD
was functioning at all so I raised
the car on stands and fitted my
pressure gauge.</li>
<li class="MsoNormal">I get a reading
of 500psi rising a bit when I rev
the engine but I’d suppose that
would drop when the oil warms up.</li>
<li class="MsoNormal">BUT, and this is
where things go pear-shaped…moving
the little lever on the RHS up and
down does not engage/disengage OD.
There is no change on the gauge to
show OD engaging or disengaging.</li>
<li class="MsoNormal">AND, the gauge
stays at 500psi even when the engine
is off. Moving the lever 20 times
has zero effect. Stayed at 500
overnight!</li>
<li class="MsoNormal">Of course, I
checked for dirt in the operating
valve area. None.</li>
<li class="MsoNormal">Likewise, the
tiny hole in the “valve – operating”
(the spindle thing which the ball
sits on)….that’s clear. And surely,
the pressure would diminish
overnight if something in that area
was partially obstructed?</li>
<li class="MsoNormal">When I remove
the pressure valve, there’s a small
spillage – no more than you’d expect
– but repeating the pressure gauge
process only returns the same
results.</li>
<li class="MsoNormal">I see in the
bible according to Norman Nock that
“Holding this lever with your thumb
and index finger, you should be able
to push the lever down lightly about
⅜” until you feel a slight spring
pressure resistance. The lever
should go down another ¼” after
encountering the resistance……” ie
there’s about ⅝” movement up &
down in that lever. Well, my lever
does move and does lift the ball,
but there’s not ⅝” movement there.
Could that be the problem area???</li>
<li class="MsoNormal">Almost
finished…keep reading!</li>
</ol>
<p class="MsoNormal" style="margin-left:18pt">So, I’m
stumped. Every time I learn something
new about the OD, it has a new trick
to baffle me.</p>
<p class="MsoNormal" style="margin-left:18pt">I’ve no 100%
sure way of telling whether it’s gone
into OD and stuck there or whether
it’s simply not going into OD at all.</p>
<p class="MsoNormal" style="margin-left:18pt">I’ve done a
lot of reading through my books and
collection of advice from the various
gurus and found reference to ODs being
stuck but those seemed to be to do
with “weak springs” which,
particularly after a long lay-off,
wouldn’t disengage. The cure for this
being a good smack on the steel plate
sandwiched in the OD from below. Well,
that seems to be a stuck mechanism
issue whereas I’m facing a hydraulic
conundrum. Or am I?</p>
<p class="MsoNormal" style="margin-left:18pt">There is what
is usually referred to as the
“pressure relief valve” adjacent to
the accumulator. The name suggested
that pressure might be stuck in that
area….but surely not overnight?</p>
<p class="MsoNormal" style="margin-left:18pt"> </p>
<p class="MsoNormal" style="margin-left:18pt">Any ideas? I
am particularly reluctant to take the
gearbox and OD out. You’ll recall the
ridiculous business of the defective
clutch kit? Well, I forget whether we
had the box in and out 3 times or 4.
I’d hoped not to do it again so soon
or ever for that matter.</p>
<p class="MsoNormal" style="margin-left:18pt"> </p>
<p class="MsoNormal" style="margin-left:18pt">I’m hoping
for a miracle of course but some sound
advice would be a godsend…………</p>
<p class="MsoNormal" style="margin-left:18pt"> </p>
<p class="MsoNormal" style="margin-left:18pt">Thanks,</p>
<p class="MsoNormal" style="margin-left:18pt">Simon</p>
<br>
</div>
</div>
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</blockquote>
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</blockquote>
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</blockquote></div>