<html><body>Overdrive engagement is controlled by having enough pressure to overcome the 8 springs keeping the clutch from engaging the annulus. (Direct drive). There has to be sufficient pressure to keep the clutch attached to the annulus ring. (Overdrive position) This requires about 600lbs. Steady pressure from the pump.<div><br></div><div>I would sit down with the Moss catalog and make a list of all the pressure parts and get new ones. Shoving washers in place is a make do and may not last long under road loads.</div><div><br></div><div>After you get a parts list, contact Overdrive Spares, UK and buy them from this company. They are the original engineers of Laycock and know what you need to make good pressure. Best regards, Hank</div><div><br><div class="reply-new-signature"></div><p>-----------------------------------------</p>From: jpaynepbr@cox.net<br>To: gradea1@charter.net<br>Cc: healeys@autox.team.net<br>Sent: Sunday May 24 2020 7:21:56PM<br>Subject: RE: [Healeys] Overdrive non return valve Question<br><br><meta http-equiv="Content-Type" content="text/html; charset=utf-8"><meta name="Generator" content="Microsoft Word 15 (filtered medium)"><!--[if !mso]><style>v\:* {behavior:url(#default#VML);}
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</o:shapelayout></xml><![endif]--><div class="WordSection1"><p class="MsoNormal">Shimmed the spring on the pump check valve by .08”. <o:p></o:p></p><p class="MsoNormal"><o:p> </o:p></p><p class="MsoNormal">Shope let me borrow an accumulator spring that was 3/64” longer.<o:p></o:p></p><p class="MsoNormal"><o:p> </o:p></p><p class="MsoNormal">Up to over 450+ psi now. OD will engage with the rear jacked up, but not while driving. On jack stands, when OD is engaged, drops to +/- 410 psi then quickly comes back up to 450+.<o:p></o:p></p><p class="MsoNormal"><o:p> </o:p></p><p class="MsoNormal">Did not change out accumulator piston/rings/sleeve or O-Rings yet, was hoping to avoid that.<o:p></o:p></p><p class="MsoNormal"><o:p> </o:p></p><p class="MsoNormal">Thinking about trying a 1/16” washer to shim the accumulator spring or is it a lost cause? <o:p></o:p></p><p class="MsoNormal"><o:p> </o:p></p><p class="MsoNormal"><o:p> </o:p></p><p class="MsoNormal"><o:p> </o:p></p><div><div style="border:none;border-top:solid #E1E1E1 1.0pt;padding:3.0pt 0in 0in 0in"><p class="MsoNormal"><b>From:</b> gradea1@charter.net <gradea1@charter.net> <br><b>Sent:</b> Sunday, May 24, 2020 10:26 AM<br><b>To:</b> 'jpaynepbr@cox.net' <jpaynepbr@cox.net><br><b>Cc:</b> 'healeys@autox.team.net' <healeys@autox.team.net><br><b>Subject:</b> RE: [Healeys] Overdrive non return valve Question<o:p></o:p></p></div></div><p class="MsoNormal"><o:p> </o:p></p><p class="MsoNormal" style="margin-bottom:12.0pt">OD Pressure should be much higher-could be 600 PSI. As I previously stated, be sure that the ball in the operating valve is the correct size- 1/4" OD in pump valve. The upper valve uses a 5/16" OD ball and you cannot mix them up, our your pressure will not be there. Too large or small a ball will not seat in the valve chamber. Also, if replacing with a new ball and spring, take a brass drift and "seat" the ball in its position. What is the condition of the piston rings and O rings...they must be up to the task as well for them to hold that huge pressure. Use sealant on all gaskets and in addition the brake ring seal to each side of the case (ignore the passage in the workshop book that says no sealant there-just be careful when applying it). Hank<o:p></o:p></p><p>-----------------------------------------<o:p></o:p></p><p class="MsoNormal">From: jpaynepbr@cox.net<br>To: healeys@autox.team.net<br>Cc: <br>Sent: Saturday May 23 2020 5:36:24PM<br>Subject: [Healeys] Overdrive non return valve Question<br><br><br><o:p></o:p></p><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:12.0pt;font-family:"Times New Roman",serif">So I pressure tested the OD at the operating valve plug – 370 PSI at 1,000 RPM in 4<sup>th</sup>. Drops to about 340 PSI when I attempt to engage the OD. OD did not engage.</span><o:p></o:p></p><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:12.0pt;font-family:"Times New Roman",serif">This is with the back end on jack stands (not the recalled ones!), so it is under no load.</span><o:p></o:p></p><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:12.0pt;font-family:"Times New Roman",serif">Held 150 PSI for about 20 minutes after being shut off and then took about 2 hours to drop below 100 PSI. At least I now have a better understanding of why these things leak so badly. Who in their right mind would design something to hold that sort of residual oil pressure?</span><o:p></o:p></p><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:12.0pt;font-family:"Times New Roman",serif">Based on all the reading, pressure is too low, but nothing appears way off?</span><o:p></o:p></p><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:12.0pt;font-family:"Times New Roman",serif">I’m using the Team.Net Tech site. <a href="http://www.team.net/www/healey/tech/big_hly/od/delborder_od.html" target="_blank"></a><a href="http://www.team.net/www/healey/tech/big_hly/od/delborder_od.html" target="_blank">http://www.team.net/www/healey/tech/big_hly/od/delborder_od.html</a></span><o:p></o:p></p><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:12.0pt;font-family:"Times New Roman",serif"> </span><o:p></o:p></p><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:12.0pt;font-family:"Times New Roman",serif">Next step is to check the non return valve spring. </span><o:p></o:p></p><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:12.0pt;font-family:"Times New Roman",serif"> Question, why would I take it to a machinist to add .084” to the head of the little plunger instead of just putting a washer on the back side of the head of the plunger? </span><o:p></o:p></p><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:12.0pt;font-family:"Times New Roman",serif">If the stem length/ insertion length into spring is that important, couldn’t I could add length to that at home with my mig welder and file it so that the spring moves freely and doesn’t hang up? </span><o:p></o:p></p><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:12.0pt;font-family:"Times New Roman",serif">From the team.net site :</span><o:p></o:p></p><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:12.0pt;font-family:"Times New Roman",serif">psi, but for proper operation, the pressure should be at 470 to 490 psi.</span><o:p></o:p></p><p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Times New Roman",serif">Now, finally... the OD low oil pressure cause and fix. A <u>fatigued spring in the non-return valve portion of the OD</u> (see Fig. 6.19). What? Is that it? You must be kidding - I waited two months for this? Yes, it does seem sort of anti-climactic, but this spring can cause major frustration. Springs are like people - as they age, they get shorter and weaker. As you can see in Fig. 6.19, the spring pushes against a ball and plunger. The purpose of this spring is to allow the ball to lift from its seat at each power stroke of the OD pump, allowing oil to flow into the pressurized accumulating chamber, </span><span style="border:solid windowtext 1.0pt;padding:0in"><img border="0" width="374" height="356" style="width:3.8956in;height:3.7043in" id="Picture_x0020_5" src="/index.php/inbox/attachment/filenameOriginal/image002.jpg/filenamefs/INBOX39542f6fa556f6a759f3fd573282b521e9f7b" alt="Image removed by sender. rework of the OD hydraulic pump valve"></span><o:p></o:p></p><p class="MsoNormal"> <o:p></o:p></p><p class="MsoNormal"> <o:p></o:p></p></div></div></body></html>