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OK, who sells magnetic plugs for MOWOG gearboxes? I'd be willing to
order from Canada ;)<br>
<br>
I don't remember exactly when I started using MT-90 in my gearbox,
but it was probably around 90-100K miles. I was hoping it would make
the O/D a bit more responsive, but was surprised that shifting
seemed smoother (I wasn't expecting it, so little-no confirmation
bias). <br>
<br>
<br>
<div class="moz-cite-prefix">On 8/4/2022 9:38 AM, Michael Salter
wrote:<br>
</div>
<blockquote type="cite"
cite="mid:CAB3i7LL54tH+2nE6eQeDcqVwP2VMjc4k0LCm+NsXrQ+C7LpncA@mail.gmail.com">
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<div dir="auto">Based upon my observations when the aluminium
overdrive accumulator housings are scored you will invariably
find that there are chips out of the non syncro 1st and reverse
gears and usually badly damaged laygear rollers.
<div dir="auto">Because these gearboxes were not fitted with
chip gathering magnet originally the tiny hardened steel chips
eventually find their way into the overdrive then through the
overdrive pump gauze (because the magnets originally fitted in
the overdrive have been lost by " the lube guy") and lodge in
the accumulator. </div>
<div dir="auto">Those chips very quickly score the cylinder as
the accumulator piston moves.</div>
<div dir="auto">If you are careful to never grind 1st or reverse
no chips will be created, that will mean that they don't go
through the laygear bearings or find their way into the
overdrive. </div>
<div dir="auto">A magnetic plug in the gearbox is great
insurance.</div>
<div dir="auto"><br>
</div>
<div dir="auto">M</div>
</div>
<br>
<div class="gmail_quote">
<div dir="ltr" class="gmail_attr">On Thu., Aug. 4, 2022, 12:13
p.m. Warren Dietz, <<a href="mailto:flyhihealey@gmail.com"
moz-do-not-send="true" class="moz-txt-link-freetext">flyhihealey@gmail.com</a>>
wrote:<br>
</div>
<blockquote class="gmail_quote" style="margin:0 0 0
.8ex;border-left:1px #ccc solid;padding-left:1ex">
<div link="blue" vlink="#954F72" style="word-wrap:break-word"
lang="EN-US">
<div class="m_-3387470703538253816WordSection1">
<p class="MsoNormal">Bob,</p>
<p class="MsoNormal">Interesting observation.</p>
<p class="MsoNormal">Only 30/40 wt non detergent oil was
used from new till 2013 at which time I switched</p>
<p class="MsoNormal">to Redline MT90 @ 181,000 miles.</p>
<p class="MsoNormal"> </p>
<p class="MsoNormal">Sent from <a
href="https://go.microsoft.com/fwlink/?LinkId=550986"
target="_blank" rel="noreferrer"
moz-do-not-send="true">Mail</a> for Windows</p>
<p class="MsoNormal"> </p>
<div style="border:none;border-top:solid #e1e1e1
1.0pt;padding:3.0pt 0in 0in 0in">
<p class="MsoNormal" style="border:none;padding:0in"><b>From:
</b><a href="mailto:bspidell@comcast.net"
target="_blank" rel="noreferrer"
moz-do-not-send="true">Bob Spidell</a><br>
<b>Sent: </b>Thursday, August 4, 2022 9:38 AM<br>
<b>To: </b><a href="mailto:flyhihealey@gmail.com"
target="_blank" rel="noreferrer"
moz-do-not-send="true">Warren Dietz</a>; <a
href="mailto:healeys@autox.team.net" target="_blank"
rel="noreferrer" moz-do-not-send="true"
class="moz-txt-link-freetext">healeys@autox.team.net</a><br>
<b>Subject: </b>Re: [Healeys] DW overdrive piston</p>
</div>
<p class="MsoNormal"> </p>
<p class="MsoNormal">Warren,<br>
<br>
Your accumulator piston and housing look to have a bit
worse scoring than mine; I used synthetic fluid for over
half the life of mine, I wonder if that made a
difference?<br>
<br>
<br>
<br>
</p>
<blockquote style="margin-top:5.0pt;margin-bottom:5.0pt">
<p class="MsoNormal"> </p>
<p class="MsoNormal"> </p>
<p class="MsoNormal">Sent from <a
href="https://go.microsoft.com/fwlink/?LinkId=550986"
target="_blank" rel="noreferrer"
moz-do-not-send="true">Mail</a> for Windows</p>
<p class="MsoNormal"> </p>
<p class="MsoNormal">This was the condition of my piston
and housing with close to 200,000 miles. Tranny was
well maintained.</p>
<p class="MsoNormal">The original metal rings lasted 53
years. So I guess with unknown quality of either of
todays metal vs rubber</p>
<p class="MsoNormal">O rings, let the experiments begin.
</p>
<p class="MsoNormal"> </p>
<p class="MsoNormal"> </p>
<p class="MsoNormal"> </p>
<div style="border:none;border-top:solid #e1e1e1
1.0pt;padding:3.0pt 0in 0in 0in">
<p class="MsoNormal"><b>From: </b><a
href="mailto:bspidell@comcast.net" target="_blank"
rel="noreferrer" moz-do-not-send="true">Bob
Spidell</a><br>
<b>Sent: </b>Wednesday, August 3, 2022 10:12 PM<br>
<b>To: </b><a href="mailto:healeys@autox.team.net"
target="_blank" rel="noreferrer"
moz-do-not-send="true"
class="moz-txt-link-freetext">healeys@autox.team.net</a><br>
<b>Subject: </b>Re: [Healeys] DW overdrive piston</p>
</div>
<p class="MsoNormal"> </p>
<p class="MsoNormal" style="margin-bottom:12.0pt">The
rings will score the inside of the piston housing,
though not badly (photo at 205K miles). Looks like
there's a side load on the piston, probably from the
spring.<br>
<br>
I donated this accumulator to another owner; never
heard how they worked. Moss shows the rings available
(but who knows?).</p>
<div>
<p class="MsoNormal">On 8/3/2022 12:36 PM, Henry G
Leach via Healeys wrote:</p>
</div>
<blockquote style="margin-top:5.0pt;margin-bottom:5.0pt">
<p class="MsoNormal">I assemble ODs using the original
metal rings and have not had any issues with
pressure or engagement/disengagement. </p>
<div>
<p class="MsoNormal"> </p>
</div>
<div>
<p class="MsoNormal">When Mr. DeNormanville stayed
up in the middle of the night to engineer the
operation of the unit, I think he decided that
the use of softer rings (sacrificial metal)
against a hardened casing was the best solution
for control and wear. If a rubber o-ring was a
better solution, he would have used one with the
proper buna rating.</p>
</div>
<div>
<p class="MsoNormal"> </p>
</div>
<div>
<p class="MsoNormal" style="margin-bottom:12.0pt">I
think the bigger problem, now-a-days, is the
availability of the metal piston rings. Rubber O
rings are a dime-a-dozen. If you contact
Overdrive Spares in the UK, they should be able to
supply the proper rings. If they too, have
decided to go with rubber, then plan on a
breakdown/rebuild in a shorter period of time than
units equipped with the original parts that last a
long, long time. Hank</p>
<p>-----------------------------------------</p>
<p class="MsoNormal" style="margin-bottom:12.0pt">From:
"Michael Salter" <br>
To: <a href="mailto:healeys@autox.team.net"
target="_blank" rel="noreferrer"
moz-do-not-send="true">"healeys@autox.team.net"</a><br>
Cc: <br>
Sent: Wednesday August 3 2022 9:38:15AM<br>
Subject: Re: [Healeys] DW overdrive piston</p>
<div>
<div>
<p class="MsoNormal"><span
style="font-size:12.0pt;font-family:"Arial",sans-serif">I
have a question about the "O" ring type of
accumulator.</span></p>
</div>
<div>
<p class="MsoNormal"><span
style="font-size:12.0pt;font-family:"Arial",sans-serif">The
way the accumulator works is that when it is
fully charged the piston moves against the
spring until the rings reach the radial
holes in the wall of the housing which acts
to relieve any excess pressure.</span></p>
</div>
<div>
<p class="MsoNormal"><span
style="font-size:12.0pt;font-family:"Arial",sans-serif">My
concern is that at 3 - 400 p.s.i. oil will
obviously get behind the "O" ring and force
the material of the "O" ring into those
radial holes and then, as the piston moves
back over them, a piece of the ring will
shear off.</span></p>
</div>
<div>
<p class="MsoNormal"><span
style="font-size:12.0pt;font-family:"Arial",sans-serif">I'm
guessing that Laycock-DeNormanville used the
complex cast iron rings rather than "O"
rings because they recognized the
possibility of this happening.</span></p>
</div>
<div>
<p class="MsoNormal"><span
style="font-size:12.0pt;font-family:"Arial",sans-serif">I'm
sure that tiny pieces of the "O" ring would
be found in the filter if this was a
problem. Anyone found them or noticed damage
to their accumulator "O" ring upon
disassembly?</span></p>
</div>
<div>
<p class="MsoNormal"><span
style="font-size:12.0pt;font-family:"Arial",sans-serif"> </span></p>
</div>
<div>
<p class="MsoNormal"><span
style="font-size:12.0pt;font-family:"Arial",sans-serif">M</span></p>
</div>
<div>
<p class="MsoNormal"><span
style="font-size:12.0pt;font-family:"Arial",sans-serif"> </span></p>
</div>
</div>
<p class="MsoNormal"> </p>
<div>
<div>
<p class="MsoNormal">On Wed, Aug 3, 2022 at 9:08
AM Bob Spidell <a
href="mailto:bspidell@comcast.net"
target="_blank" rel="noreferrer"
moz-do-not-send="true"><bspidell@comcast.net></a>
wrote:</p>
</div>
<blockquote style="border:none;border-left:solid
#cccccc 1.0pt;padding:0in 0in 0in
6.0pt;margin-left:4.8pt;margin-top:5.0pt;margin-right:0in;margin-bottom:5.0pt">
<p class="MsoNormal"
style="margin-right:0in;margin-bottom:12.0pt;margin-left:153.6pt">I
put one in my BJ8's O/D. It's
subjective*--O/Ds seem to work a little<br>
quicker with cold, thick oil than hot oil--but
it cuts maybe a third off<br>
engagement time on average. I had the O/D on
the bench and disassembled,<br>
and the current one had a scored barrel so,
why not? Engagement isn't<br>
much, if any, harsher than before which, I
believe is the reason DMH<br>
wanted the weaker, smaller spring. If I'd
known about it, I might have<br>
bought AHSpares' with an O-ring instead.<br>
<br>
* I've never really 'timed' O/D functioning,
it would be a bit awkward;<br>
anyone done it? I usually tap the clutch pedal
when engaging O/D, and<br>
give a little throttle when disengaging. I
thought mine engaged a little<br>
quicker when I switched to synthetic fluid
from engine oil, but in all<br>
cases confirmation bias may be involved.<br>
<br>
<br>
<br>
On 8/2/2022 8:09 PM, Joseph Costa wrote:<br>
> Has anyone installed their upgraded
overdrive piston? If so, is it<br>
> worth the trouble ?<br>
><br>
> Joe<br>
> BN1 #923<br>
></p>
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