[TR] A Type OD

Anthony Rhodes spamiam at comcast.net
Sun Apr 22 04:45:01 MDT 2018


Terry,

I think it sure could engage more weakly with all the switches and the relay in series.  

You could test the resistance of all of them when they are on.  

Or you can test the voltage at the solenoid and see how far it dropped from battery  voltage when active.  

I would also think about hot wiring the solenoid with a single manual switch (fused with a slow blow) to compare the solenoid voltage and to compare the strength of actuation and to see if it stops the OD from stuttering in and out after the 20 minutes.  

-Tony

Sent from my 1837 Babbage Analytical Engine

> On Apr 21, 2018, at 2:00 PM, triumphs-request at autox.team.net wrote:
> 
> 
> Message: 2
> Date: Fri, 20 Apr 2018 18:56:21 -0400 (EDT)
> From: TERRY SMITH <t>
> To: triumphs at autox.team.net
> Subject: [TR] A Type OD
> Message-ID: <237439069.23752.1524264982105 at connect.xfinity.com>
> Content-Type: text/plain; charset="utf-8"
> 
> Hello, everyone. 
> 
> I've had overdrive issues with my TR3 since having it rebuilt two years ago.   The first issue was that it wouldn't drop out of OD.  Inspection showed that the shop that rebuilt it had put a bolt in to use as a stop for the solenoid plunger so it would not drop down too far to pick up again.  Good so far.  But he hadn't followed through with a nut on the bottom of the bolt to hold it securely.  Result was that sometime during the transit from the shop to home, or during finicky re-installation of the tranny into the car, the bolt rose up and got cockeyed, such that the plunger couldn't drop down.  If I waited a day, though, it would.  Whatever, I fixed that with a new bolt/nut and the OD came out of of OD when and as it should.
> 
> My biggest worry was that before I knew the car wasn't disengaging OD, I tried backing up.  I met some substantial resistance and am pretty sure I didn't power through it.  OD seemed to work okay after the fix, so subject to your advice, am thinking I didn't overly damage the  OD.
> 
> Next, the OD would work for about 20 minutes, then drop out.  A few times I could actually feel it chatter as it rapidly kicked in and out before dropping out altogether.  That made me think it was likely electrical.  I swapped out the solenoid, relay and the OD switch.  No improvement as intermittency remained. 
> 
> Now I've retired (end of January) so can spend a bit more leisure time looking into this. 
> 
> I've starting by rewiring from the relay forward so I know all the contacts are good (some are spade connectors on the isolator switches were almost 60 years old and felt loose and despite spraying with electrical contact cleaner, oily).  I've replaced the isolator switches too since I'm in there and seemed to have buggered up the spade terminals on the old ones, bending them but not severely during tranny or tunnel reinstall.  I've tested them with a multimeter using the spacer washers provided and they test good in all three gears.  I've tested the solenoid using power direct from the battery and get a very satisfactory snap when it kicks in.  But here's the thing:  when I've tested with all the circuits connected--that is, the relay and switch, the snap isn't pronounced, but the solenoid does kick in as it should. 
> 
> I've adjusted the actuating lever to the solenoid so that it's backed off from the o-ring, and made sure it doesn't kink the plunger from dropping.  I did this per the book, using the 3/16 drill bit, which assumes that operating oil pressure is sufficient then.  I've also pulled the operating valve spindle and blew through it with lung power.  It let air through.  To be sure, I blasted it with compressed air and (hmmm) to my uneducated sense it seemed to blow through better, meaning there may or may not have been some small restriction in the channel.  We'll see.
> 
> So...where am I.  Next step is to jack the rear of the car up and put it on stands so I can run the car and put it in OD to see if it kicks in and out.  Then run it awhile to see if it stays in. 
> 
> Now the questions: 
> 
> 1)  Am I okay to assume that adding the additional circuitry will reduce the "snap" sound when the solenoid kicks in.  Or is that sound even relevant as long as the solenoid actuates.
> 
> 2) When I test the OD on blocks, do I need to increase engine speed beyond idle to get a proper test.
> 
> 3) If the thing still tests sketchy, where can I get an oil pressure gauge that will screw into the operating valve so I can really know what's going on?
> 
> 4) Do I remember correctly that after turning off the OD with the car stationary, it takes longer than when it's actually on the road?
> 
> Thank you, everyone, for your patience with this ridiculously long post.
> 
> Best,
> 
> Terry Smith, '59 TR3A  TS 58667
> 
> New Hampshire



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