Jump to content

Recommended Posts

My long door TR2 today passed its roadworthy (MOT) with flying colours.

However, the overdrive wasn't working after I adjusted it so I asked the workshop to test it for me. It still doesn't work.

The pump pressure is good and the solenoid is working normally. When engaged the OD seems to work, the output shaft moves slightly indicating something is happening internally, but the revs don't change.

He doesn't know what is wrong with it so it looks like out with the box and send it to the OD specialist. He isn't available for a couple of months so I can use the car without the OD until then.

I want to get the interior finished and can't really do so if the box has to come out again

I thought I would see if anybody here has experienced these symptoms as an early fix without removing the box would be great.

Link to post
Share on other sites

Hi John,

assuming the solenoid works, the loom  and switches are good, there is enough oil etc etc then it may simply be a matter of re-rigging the solenoid and shaft.

Slacken off the solenoid clamp. Move the rigging arm to align with the rigging hole (use a drill ect to check alignment) and then move it the arm a very very small amount beyond the rigging hole (remove the drill first) - then tighten the solenoid clamp.

 

Roger 

Link to post
Share on other sites

Thanks Roger. I adjusted it like that before I took it to him. He then adjusted it although I didn’t question him in detail exactly how he adjusted it.  It is possible but not likely it still isn’t adjusted properly. I doubt it because he has been a Triumph specialist since the 1960s.

If I put the rear end on axle stands, run it in top with the clamp loose and pull the actuating lever on the right side of the OD until it either works or reaches full movement, will it do any damage? 

Edited by John McCormack
Link to post
Share on other sites

Hi John,

             that would work but be VERY VERY careful. Make sure the front wheels are well chocked.

2500rpm - advance the lever and it should drop in and reduces revs to near 2000rpm.

 

Be careful

 

Roger

Link to post
Share on other sites

It was suggested to me that testing an o/d like that would not work as there was no (I can't find the right word) weight of the car.

In fact I had re set mine and thought it was still not working as I tested it as above. On the road it worked fine.

Link to post
Share on other sites
28 minutes ago, TwinCamJohn said:

It was suggested to me that testing an o/d like that would not work as there was no (I can't find the right word) weight of the car.

In fact I had re set mine and thought it was still not working as I tested it as above. On the road it worked fine.

Interesting. There are no switches or sensors to cause this that I am aware of. I have often engaged OD on my other TR2 with the car on stands.

My concern is that operating the lever by hand may over extend the operating shaft beyond the point it operates the valve that lets the oil pressure through to the OD. I don't know enough about the OD internals to know if this could be a problem.

The car will be on stands tomorrow when I go over to the workshop, I will see what the mechanic and I can do then.

Link to post
Share on other sites

I don't think you will be able to operate the leaver by hand there is too much pressure, you could use multi grips or similar but be careful not to go too far, better to check the adjustment by the manual and it should work through the solinoid.

 

Graham

Link to post
Share on other sites

With the car on axles stands it is more likely that the speed will rise a bit rather than the revs drop when the overdrive cuts in. 

I tried it when I had my issues. 

Link to post
Share on other sites

So the revs don't drop,

the speedo goes up. Safest way to look at this is remove the prop at the gearbox, then

you are not spinning that, the axle or the wheels. Then using the 11/64 th drill in the alignment hole, AS A START,

But lean on the drill as you clamp up. To counter the fact that these holes are 60 odd years old, and likely ovalish still no joy? Next you want to remove the operating valve, (7/16) nut on top or the unit, allow for some oil seepage. With a magnet 1/4 inch is great , pull the spring, ball bearing and valve, clean the valve, blow through the hole, replace the ball bearing for a new one, critical this, seat with a mild drift, ally is perfect, and gentle taps, reassemble and reset alignment.

Changing the ball bearing for new, and seating on the operating valve are critical  processes in sorting the operating valve, then with the prop shaft still disconnected, if the o/d works speedo reading will rise, though in truth you will sense the gearbox jump. All this is in the w/s manual, and all works, ask me how I know?

John.

Link to post
Share on other sites
8 minutes ago, John Morrison said:

So the revs don't drop,

the speedo goes up.

John.

When on axle stands without road resistance yes. 

 

On the road we see  the revs drop until the car picks up momentum

Edited by Hamish
Link to post
Share on other sites

FWIW when I had my three overdrive gearboxes rebuilt I was asked about what pressure setting i wanted. The options were standard around 450psi, fast road (a bit more snappy) around 600psi  and full race (snap halfshafts) God knows.rebuild the box every season.

I opted for the mid range as I like the overdrive to talk to me.

After initial problems with burn out of solenoids caused by failure of the solenoid to switch to holding current Duff push switch in the heads. I now have an overload circuit box which sits there working and protects the solenoids. The overdrive either works or it doesn't meaning there is an issue with the electrical circuit butr the solenoid can never be overload and burnt out.

I do not consider them to be a consumable.

This system is foolproof and works amazingly well.

I would suspect that the pressure on your internal pump is not set correctly. Even with the lowest setting you do feel a faint surge as the overdrive kicks in.

Rod

Link to post
Share on other sites

Hi Roger,

Fully aware of this but I had two new ones fail in one year, not a good situation? If this switch fails or sticks it will go into meltdown. It is a nasty primitive system as it it just a small floating pin that moves to break a set of points like a distributer.

Link to post
Share on other sites

I worked with the mechanic today going over the car. He pointed out a few minor details I hadn't picked up. He had driven the car for about 6 miles and was delighted with it.

The OD. We had the car on big workshop stands both ends so could run it safely. OD oil pressure is very good, no problem there.

When the OD is engaged the output flange moves slightly as the OD does its stuff. The normal gear noises in the box also change indicating the OD has engaged. However, no change in output shaft revs.

We physically moved the operating lever to make sure it was fully home without any change. 

The OD internals are working but the OD isn't engaging. This could be because it has been assembled incorrectly when the box was overhauled. The mechanic, who didn't do the box, rebuild, can't identify the cause. He rang the OD specialist, unfortunately in another state, who can't pick it from the symptoms.

Unfortunately the gearbox will have to come out and be set up on a bench.

Looking at it in a positive light 28 months ago I bought a pile of bits home in two trailer loads. It is now a 'new' long door TR2 that drives very nicely. The interior isn't in it yet so the box can come out and go back in without too much trouble. The OD can be repaired while I do some finishing touches to the car. 

Once the OD is done the interior and weather gear can be completed. All will be good.

 

Link to post
Share on other sites

John

If you want to learn a bit about the operation of your overdrive you can download the original triumph manual from Tony Drews webpage

https://www.tonydrews.com/Overdrive/A-type OD manual.pdf

link to his webpage

https://www.tonydrews.com

cheers

Alan

 

Link to post
Share on other sites
49 minutes ago, RogerH said:

There is a lovely statement in the  OD service manual Page 5 'Care and Lubrication'  DO NOT USE EP oils

So what do we now put in EP90.

 

Roger

I don’t, why would you ? Is that what ORS and other specialist recommend ?

Mick Richards

Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
×
×
  • Create New...

Important Information

Please familiarise yourself with our Terms and Conditions. By using this site, you agree to the following: Terms of Use.