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OD drop out

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tahoe healey

tahoe healey

Yoda
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I've just experienced drop out of the OD for the first time. It happened several times. I've searched the archive but didn't find exactly what I needed. I've checked the dash switch, gear box oil, and gearshift 2nd/3rd-4th switch. That, in my opinion, leaves the pressure spring/ball bearing switch. How can I test it? I was thinking to open it and clean the parts. Many years ago I had a metal sliver lodge in the opening not allowing the ball to seat. If that isn't it, then it may be the solenoid coil not being able to hold the operating lever open. Best way to test this? Any suggestions?
Thanks
TH
 
Did you check the relay? That's what my O/D when the relay points got too burnt. Of course, if you'd rather take the O/D apart for fun ...
 
Are you referring to the throttle switch? If so it checks out okay. I will clean the points as it seem to be intermittent that may be the cause. Thanks. Good thought.
 
tahoe healey said:
Are you referring to the throttle switch? If so it checks out okay. I will clean the points as it seem to be intermittent that may be the cause. Thanks. Good thought.
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Nope. There's a relay in addition to the throttle switch (part of the same circuit, though). Moss part# 542-170 for BJ8 ($36.95) or 542-260 for earlier cars ($178.95--ouch!). It's on the scuttle next to the throttle switch. When mine started acting up in Canada I opened it up, filed the points (we all carry points files, right?) and it got us home--another 1,500miles or so.
 
Tahoe, In the last week or so I have been putting in a new wiring harness on my car. Since I relocated some things because I am putting in two fuse boxes I had to extend some wires. When I was making connections for the OD relay, I didn't have any more of the Original type connectors so I started to improvise by using an American style male inside an Original British female connector. Then I thought better of it because I thought 'this is not good, my OD will probably be dropping in and out from these modified connectors.' So the moral to the story is check all your electrical connections before you tear into anything serious. Dave C.
 
I do not have the relay Bob mentioned. I believe it was replaced long before I got the car (BJ8 phase one) with something that says "Lucas 6RA". I'm checking this out. I also will try driving with a little lateral pressure on the gear shift to see if the switch may be the problem even though it checks out with out the engine running.
TH
 
Best way to know the condition of the overdrive is to manually push the lever on the opposite side of the gearbox from the solenoid. There's a loop on the end that should line up with a hole in the casting (for setting purposes). With all electrical things out of the picture ( leave the switch off ), putting this in position as you drive forward opens the path for oil to flow to operate the overdrive. Be careful, as the drive shaft is right there. A co-pilot would be ideal. When released, the lever should spring back and you'll be back to direct drive. At least you'll know if the unit is working this way. Bob
 
Same thing happened to me on the way to and from our last meeting. My OD would drop out for a second or two. David said it sounded like electrical. I found a loose connector in the wire going to the relay. I will give it a try to be sure this W/E.
 
Well, I may have gotten lucky. I played with the shift lever back and forth a bit to see if it was the safety switch. Now she works fine. We shall see. Over the years, I have done the over drive manual over ride and all that stuff so I am familiar with much of it. The surprise is that I did not have an original relay but what I have is working and vintage Lucas no less.
 
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