Overdrive

[Richardtr3a]

Thanks for the answers. If it is dry over the week end I will try a longer run. Should it be fast or regular ??

On Monday I am planning to order more oil from Opie Oils.. I am using Dynalite  Gear 40. On the label it says  "  It is non-hypoid & non-friction modified gear oil , safe with bronze, copper and  brass.Safe for overdrive and pre-selector units "

Is there a better gear box oil ?

Please send any recommendations.

Richard & H

Edited December 15, 2023 by Richardtr3a
spelling

[RogerH]

5 minutes ago, Richardtr3a said:

Thanks for the answers. If it is dry over the week end I will try a longer run. Should it be fast or regular ??

On Monday I am planning to order more oil from Opie Oils.. I am using Dynamite  Gear 40. On the label it says  "  It is non-hypoid & non-friction modified gear oil , safe with bronze, copper and  brass.Safe for overdrive and pre-selector units "

Is there a better gear box oil ?

Please send any recommendations.

Richard & H

Hi Richard,

I think you will find that is Dynalite oil and that should work OK.

I use Penrite GB40, which also works well.

 

Roger

[John McCormack]

On 12/15/2023 at 11:21 PM, rcreweread said:

Hi - I'm sorry, but in my experience, this is not totally true - if the oil level in the gearbox and OD has fallen to the extent that the OD is "dry"and stopped operating, it can sometimes need a run of up to 20-30 mins to get it going and purge any air out of the hydraulics within the OD - once it starts operating, then it should engage/disengage almost instantly on being operated .

Cheers Rich

The overdrive will work after only a few seconds of driving the TR or running it on axle stands. If you top it up to the fill line from empty and go for a drive by the time the overdrive is engaged it will engage if all is correct. In 48 years and probably 30 gearbox oil changes over three Trs I've never had an overdrive not engage within a few seconds at the most.

If it doesn't I suggest it will be because not enough oil was put in or the overdrive oil pump isn't up to the task.

[ianc]

The other matter which will cause a considerable delay to engagement (or even a complete failure to engage) is if the pull-in coil in the solenoid has gone open-circuit, leaving just the hold-in coil energised.

In the 1960s, my brother had just this problem, and he had to drive a considerable distance before the overdrive engaged.

Easily fixed with replacement of solenoid, or, if the internal connection has parted at the switch on the top of the solenoid and one is competent with a soldering iron, a repair may be possible.   See my 1973 article in Section F4 of the Technicalities booklet.

Ian Cornish

[BlueTR3A-5EKT]

1 hour ago, ianc said:

The other matter which will cause a considerable delay to engagement (or even a complete failure to engage) is if the pull-in coil in the solenoid has gone open-circuit, leaving just the hold-in coil energised.

In the 1960s, my brother had just this problem, and he had to drive a considerable distance before the overdrive engaged.

Easily fixed with replacement of solenoid, or, if the internal connection has parted at the switch on the top of the solenoid and one is competent with a soldering iron, a repair may be possible.   See my 1973 article in Section F4 of the Technicalities booklet.

Ian Cornish

Yes, Ian that is an issue my TR2 had also.   I tied a piece of string to the solenoid lever and passed it up to the side of the gearstick through the split gear lever gaiter.   
To operate the overdrive the trick was once in 4 th. Pull out dash switch and pull on string.    Overdrive then engaged.    Disengaging was simple push switch in and be sure the string was loose.
 

  I eventually paid Pete Buckles, my local spares secretary, 30 bob for a replacement solenoid.  

Edited December 17, 2023 by BlueTR3A-5EKT

[RogerH]

9 minutes ago, BlueTR3A-5EKT said:

Yes, Ian that is an issue my TR2 had also.   I tied a piece of string to the solenoid lever and passed it up to the side of the gearstick through the split gear lever gaiter.   
To operate the overdrive the trick was once in 4 th. Pull out dash switch and pull on string.    Overdrive then engaged.    Disengaging was simple push switch in and be sure the string was loose.
 

  I eventually paid Pete Buckles, my local spares secretary, 30 bob for a replacement solenoid.  

Hi Pete,

can you get me one at that price.

 

Roger

[BlueTR3A-5EKT]

7 minutes ago, RogerH said:

Hi Pete,

can you get me one at that price.

 

Roger

Given a TARDIS.  The answer is yes.   You could just pop round to 11 Crossways Road in Mitcham and see if he is still trading on Saturday afternoons……

They were in Jaguar Daimler packages and the armature was threaded 1/4” so you fitted a bolt and lock nut to set the pull in clearance.  
Too low and the thing refused to pull in.  Too high and the od remained engaged.  

Triumph have a fixed length armature and possibly an adjustable screwed/locknut stop below the lever.   If it has a rubber buffer BEWARE they go sticky with oil soaking and hold the lever down.   That ends up melting the wiring if the pull in circuit is continuously engaged trying to pull the lever off the sticky rubber stop.  My own experience talking here.

Edited December 17, 2023 by BlueTR3A-5EKT

[Richardtr3a]

Thanks for all  the technical advice on the Forum. I have checked my records and the overdrive was rebuilt by Od Spares and has only covered 20k miles in ten years

I have just watched the weather forecast on BBC and it looks like wet and colder until Christmas. Unless it changes I will leave the TR3 in the garage until we have a dry couple of days. Then I will give it a proper run.

Thanks Richard & B

PS I must fit the Antifreeze

[John McCormack]

On 12/18/2023 at 9:46 AM, Richardtr3a said:

Thanks for all  the technical advice on the Forum. I have checked my records and the overdrive was rebuilt by Od Spares and has only covered 20k miles in ten years

I have just watched the weather forecast on BBC and it looks like wet and colder until Christmas. Unless it changes I will leave the TR3 in the garage until we have a dry couple of days. Then I will give it a proper run.

Thanks Richard & B

PS I must fit the Antifreeze

In normal times we would be having 35degC+ days about now. Yesterday was about 20 degC and bucketing down, for our Christmas lunch run. First time ever I've not taken a TR on a club run.

[janduppen]

Hi Richard,

If all else fails,there is a nice tip in the Moss catalog about OD troubleshooting.

If the gearbox / OD were overhauled, all oil had been drained. When refilling, air bubbles can remain which interfere with proper action. You say the car had run several thousand miles after overhaul, so this may not be your problem. However, the following tip is easy to do and it may also help someone else. It sure did the trick for my TR3a.

Block the front wheels and put the rear on axle stands, then carefully loosen the operating valve plug (on top right side of the OD). Start the engine with a fast tick-over. Engage second gear and oil should bleed past the loosened operating valve plug. Any air should also bleed, after which the operating valve plug can be re-tightened.

If no oil bleeds out, the pump is inoperative.

Good luck,

Jan Duppen (Holland)

 

[janduppen]

Hi Richard,

If all else fails,there is a nice tip in the Moss catalog about OD troubleshooting.

If the gearbox / OD were overhauled, all oil had been drained. When refilling, air bubbles can remain which interfere with proper action. You say the car had run several thousand miles after overhaul, so this may not be your problem. However, the following tip is easy to do and it may also help someone else. It sure did the trick for my TR3a.

Block the front wheels and put the rear on axle stands, then carefully loosen the operating valve plug (on top right side of the OD). Start the engine with a fast tick-over. Engage second gear and oil should bleed past the loosened operating valve plug. Any air should also bleed, after which the operating valve plug can be re-tightened.

If no oil bleeds out, the pump is inoperative.

Good luck,

Jan Duppen (Holland)