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Overdrive packed up!


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My super reliable Tr6 has developed an overdrive fault !

last thursday we drove down to winchester, and for a minute the overdrive was dropping out when cruising at about 80

on the way home it was fine, at ‘motorway speed’ all the way

yesterday we went for a potter and the overdrive is not working at all.

j type overdrive as a 74 car

i suspected the switch but upon inspection it looks very solid and simple, so will investigate the electrics further

think i’ll wire up a test light to the solenoid to see if it’s getting power, and earth.

the j type has no relay , just the column switch to supply 12v via the 3/4 gearbox switch to the ‘solenoid’ ( which is actually a valve on the j type)

i shall report progress, but suggestions welcome !

steve

 

 

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Steve - check your gearbox oil level, and whilst you are under the car, hold the solenoid and get someone to operate the OD- you should be able to feel the solenoid operating through its casing to isolate that as an issue or not

Good luck

cheers

Rich

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Steve,

I had similar issues on a Stag overdrive J type.

I rigged a power lead  from the battery, fitted a small switch and connected to the solenoid. Engine off by the way.

Then when I turned on the switch, loud click as solenoid operated, then I did it again and again and again, presumably heating the solenoid. Then it stopped working. Left it an hour or so and tried again, worked until warm then stuck once more.

I had thought it was sticky after a winter layoff and I was flicking it to free up any corrosion with repeated operation, however turned out to get progressively worse as it got warmer. Fitted a new solenoid and it worked instantly and perfectly thereafter. Later I heard this was a fairly common fault.

Incidentally unless you have some very thin spanners  then buy a solenoid J type spanner from a TR vendor, with a standard spanner perhaps not possible at all.  Probably took 15 minutes to change and there is no oil loss when you remove the old one so a very easy job.

 

Alan

 

Edited by barkerwilliams
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Sounds like the solenoid isn't earthed properly. Mine did this, the earth lead was loose then came off.

I have also had the solenoid fail when hot. The solenoid operated electrically but the seals go hard over time and won't hold oil pressure when the oil thins out.

Check the earth, then try a new solenoid.

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Thanks John

90% of car problems are electrical so yes i’ll be checking the wiring first.

steve

ps, love to a pic of you s&s34!

Edited by Steves_TR6
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14 minutes ago, Steves_TR6 said:

Thanks John

90% of car problems are electrical so yes i’ll be checking the wiring first.

steve

ps, love to a pic of you s&s34!

Even better, here is the Safety Plan I prepared for her as a guide to crew when sailing offshore. It has a few photos and other details.

Do you sail?

Safety Plan - Morning Bird.doc

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11 hours ago, Steves_TR6 said:

Thanks guys, i’ll investigate in the week and report back....

Hi Steve,

I hope you have not got multi grade oil in your gear box/OD as the this type of oil can start to break up and produce a white foam - sludge which then blocks up some of the oilways in the OD. People have listen to the supposed bad press on hypoid oil and ended up with a big bill for the OD to be stripped down and cleaned out. This is what has happen to a number of our TR members in our group!

Bruce.

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Some time ago my overdrive started dropping out intermittently, the first thing I checked that the oil level was good, it was. So thinking it was the solenoid, I rigger a multi-meter to read voltage on the lead going to the solenoid. No problem statically in the garage, worked every time. However, on the road I got some very interesting results as the voltage going to the solenoid varied by a wide margin. When the voltage dropped to below 8v the solenoid dropped out and the overdrive disengaged. So I investigated the voltage at every connection all the way back to the battery. Multiple issues were found: dirty bullet connectors, a wire hanging onto the bullet by a few threads, and most interesting was battery voltage drops, whilst driving along, weird. I had some very occasional starting issues nothing significant. With all wiring issues sorted out, the performance was much better but it was still occasionally dropping out. I installed a new battery and have not an issue since. Tricky stuff this electricity in old, well, used cars. Don't assume it is just one issue.

Mick

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53 minutes ago, John McCormack said:

Even better, here is the Safety Plan I prepared for her as a guide to crew when sailing offshore. It has a few photos and other details.

Do you sail?

Safety Plan - Morning Bird.doc 4.1 MB · 7 downloads

Great looking yacht 

very similar to my dads old hustler 30. 

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Last year I also found my J type was dropping out randomly. Tranny oil was a little low so I topped it up but the problem persisted. Later on a club run the car would not start but when jump started it would run. Turned out the battery positive cable going into the battery connector was badly corroded. It would pass low current like the ignition but higher currents like the starter motor and possibly the OD solenoid could not overcome the resistance. Since I cleaned up that cable and connector I had no further issues. Could have been a coincidence, this driving season is just starting and I'll see how things go.

Stan

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Thanks everyone!

i put the correct gearbox oil in in about 2013, if i recall its ep80 gl4?

car electrics are good, no other issues, and the J type doesnt draw much power

will check oil, power feed, earth, alignment of moon and stars :-)

steve

ps, yes John am a keen sailor .....post-9473-0-21153300-1519996042_thumb.jpegpost-9473-0-11516000-1519479098_thumb.jpeg

Edited by Steves_TR6
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9 hours ago, John McCormack said:

Even better, here is the Safety Plan I prepared for her as a guide to crew when sailing offshore. It has a few photos and other details.

Do you sail?

Safety Plan - Morning Bird.doc 4.1 MB · 25 downloads

Lovely boat John :-)

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So, took a look under the tr6 this evening to check out the overdrive.

initial ‘thats it’ moment turned out to be false alarm, as the wire and spade connector ‘dangling freely’ were from a suppressor not the actual overdrive connectors.

however the earth spade connector was quite loose.

so i tightened both power and earth connectors gently with long nose pliers.

since i was under there i cleaned off the rust prevention oil a bit too :-)

then i checked the solenoid ‘clicked’ when 12v applied, which it did.

i also checked the footwell connections for the gearbox switch, which were loose and had an inline fuse that shouldnt have been there, so removed that.

ignition on, in 4th, solenoid now clicks when overdrive switch engaged.

quick testdrive and overdrive working !

marvellous to have such sunny weather to get under the car and fix a problem of an evening :-)

steve

F5CBFFF6-CE71-42C1-8722-3B95B5C0B6BF.jpeg

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Great news to have a cheap fix and it’s nothing catastrophic 

:D

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Good news. Simple cheap fixes don't happen often enough.

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Yes, a loose connection either at the solenoid or at the , now removed, additional fuse holder.

thorough testing just now to confirm all is ok :-)

steve

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