[Healeys] Overdrive pressure not releasing.

gradea1 at charter.net gradea1 at charter.net
Sun Apr 17 14:47:12 MDT 2022 

Don't think that issue has been resolved. Moss sells the replacement
as: 

		Austin Healey 100, 100-6, 3000
		Clutch, Gearbox & Drivetrain
		Overdrive BN1 [1]
		76
		O-RING
		BN1

	--79 866-690 [2] 

	  [3]

	O-RING 89 cents each-chafe them and replace them. Hank

	 [4]---------------------------------------From: "Michael Salter via
Healeys" 
To: "Bob Spidell"
Cc: "healeys at autox.team.net"
Sent: Sunday April 17 2022 12:04:24PM
Subject: Re: [Healeys] Overdrive pressure not releasing.

 Actually Bob I've never used an "O" ringed accumulator. 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.  Does
anyone know how that has been solved? 
 M  
 On Sun., Apr. 17, 2022, 2:49 p.m. Bob Spidell,  wrote:
  Michael,

 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).

 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?

On 4/17/2022 9:31 AM, Michael Salter via Healeys wrote:
   Simon, 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. This conclusion is based upon your
discovery that the pressure in the accumulator, as indicated on the
gauge, does not leak away overnight. 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.
 This process would indeed take some time but would certainly
completely relieve most, if not all the residual accumulator pressure
overnight. 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.
 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..
 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.
 Bad news is that this pin cannot be accessed without removing and
disassembling the overdrive. 
 M

 On Sat, Apr 16, 2022 at 1:19 PM Simon Lachlan via Healeys  wrote:

	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!) 

	* I’d say that the OD has done +/- 15k miles since a total rebuild
by Overdrive Spares here in UK.
 	* The OD had issues before Christmas (21) and was sorted out by OD
Spares. The accumulator was uprated and pressure issues sorted.
 	* OD functioned 100% on the few times I’d been able to take it out
since then until..
 	* One day, the OD stopped functioning.
 	* I checked the electrics. All fine there so I delved a bit deeper.
 	* It had fried its solenoid which I replaced. But…
 	* That did not fix the problem so…
 	* I decided that the operating valve’s adjustment might be off
so..
 	* I bought a dial gauge and hoped to sort it out precisely rather
than by “feel”, which I lack in this area.
 	* 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.
 	* 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.
 	* 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.
 	* AND, the gauge stays at 500psi even when the engine is off. Moving
the lever 20 times has zero effect. Stayed at 500 overnight!
 	* Of course, I checked for dirt in the operating valve area. None.
 	* 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?
 	* 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.
 	* 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???
 	* Almost finished…keep reading!

	So, I’m stumped. Every time I learn something new about the OD, it
has a new trick to baffle me. 

	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. 

	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? 

	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? 

	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. 

	I’m hoping for a miracle of course but some sound advice would be a
godsend………… 

	Thanks, 

	Simon 

	    _______________________________________________
 Support Team.Net  [5]http://www.team.net/donate.html [6]
 Suggested annual donation $12.75

 Archive:  [7]http://www.team.net/pipermail/healeys [8] 
[9]http://autox.team.net/archive/healeys [10]

Healeys at autox.team.net
 [11]http://autox.team.net/mailman/listinfo/healeys [12]

 Unsubscribe/Manage: 
[13]http://autox.team.net/mailman/options/healeys/michaelsalter@gmail.com
[14]

 _______________________________________________
 Support Team.Net  [15] "_blank" rel="noreferrer">
"http://www.team.net/donate.html" target=
 "_blank">http://www.team.net/donate.html
 Suggested annual donation $12.75

 Archive:  [16] "_blank" rel="noreferrer">
"http://www.team.net/pipermail/healeys" target=
 "_blank">http://www.team.net/pipermail/healeys 
"http://autox.team.net/archive/healeys" target="_blank" rel=
 "noreferrer"> [17]
target="_blank">http://autox.team.net/archive/healeys

 "noreferrer">Healeys at autox.team.net
 [18] "_blank" rel="noreferrer">
"http://autox.team.net/mailman/listinfo/healeys" target=
 "_blank">http://autox.team.net/mailman/listinfo/healeys

 Unsubscribe/Manage: 
"http://autox.team.net/mailman/options/healeys/bspidell@comcast.net"
 target="_blank" rel="noreferrer">
"http://autox.team.net/mailman/options/healeys/bspidell@comcast.net"
 target=
 "_blank">http://autox.team.net/mailman/options/healeys/bspidell@comcast.net

 _______________________________________________
 Support Team.Net  [19]http://www.team.net/donate.html [20]
 Suggested annual donation $12.75

 Archive:  [21]http://www.team.net/pipermail/healeys [22] 
[23]http://autox.team.net/archive/healeys [24]

Healeys at autox.team.net
 [25]http://autox.team.net/mailman/listinfo/healeys [26]

 Unsubscribe/Manage: 
[27]http://autox.team.net/mailman/options/healeys/michaelsalter@gmail.com
[28]

  

Links:
------
[1] https://mossmotors.com/overdrive-bn1
[2] https://mossmotors.com/o-ring-27?assoc=172485
[3] https://mossmotors.com/o-ring-27?assoc=172485
[4] https://mossmotors.com/o-ring-27?assoc=172485
[5] http://www.team.net/donate.html
[6] http://www.team.net/donate.html
[7] http://www.team.net/pipermail/healeys
[8] http://www.team.net/pipermail/healeys
[9] http://autox.team.net/archive/healeys
[10] http://autox.team.net/archive/healeys
[11] http://autox.team.net/mailman/listinfo/healeys
[12] http://autox.team.net/mailman/listinfo/healeys
[13]
http://autox.team.net/mailman/options/healeys/michaelsalter@gmail.com
[14]
http://autox.team.net/mailman/options/healeys/michaelsalter@gmail.com
[15] http://www.team.net/donate.html
[16] http://www.team.net/pipermail/healeys
[17] http://autox.team.net/archive/healeys
[18] http://autox.team.net/mailman/listinfo/healeys
[19] http://www.team.net/donate.html
[20] http://www.team.net/donate.html
[21] http://www.team.net/pipermail/healeys
[22] http://www.team.net/pipermail/healeys
[23] http://autox.team.net/archive/healeys
[24] http://autox.team.net/archive/healeys
[25] http://autox.team.net/mailman/listinfo/healeys
[26] http://autox.team.net/mailman/listinfo/healeys
[27]
http://autox.team.net/mailman/options/healeys/michaelsalter@gmail.com
[28]
http://autox.team.net/mailman/options/healeys/michaelsalter@gmail.com

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://autox.team.net/pipermail/healeys/attachments/20220417/1b369b88/attachment.htm>

More information about the Healeys mailing list