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Richardtr3a

Gearbox selectors

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My gear selection on the 3A seems to be a bit clumpy and I would not mind too much but I drove the Register TR 2 when it was on tour, and the gear selection was very smooth. My gearbox was rebuilt so I am wondering if the selectors need adjustment. I have seen a diagram of the selector mechanism with a ft/lb gauge attached and instructions on how to adjust. But I can not find it now.

Does any one know how to make this adjustment.

Thanks Richard & B

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Hi Richard,

 there are a number of things that make selection clunky/stiff.

It could be the selector rods detent balls/springs - but could be something else.

Remove the GB top cover (off with the tunnel etc). In the top cover on the rear flange you will see three slotted grub screw heads.

You can turn these back until they are flush - that may help, but!!!

if you decide to take the screws out then make sure you know exactly where all the springs and balls go.

When I first got my 4A on the road the gearbox was like driving a Colchester Lathe - gear selection was very heavy.

How well is the clutch releasing - this can cause bad selection.

Does it improve when warmed up - do you use a thick GB oil.

 

https://static1.squarespace.com/static/5c6dec53b10f25d4edf0b3f7/t/5d019590f90de40001aacd9b/1560384913595/Gearbox+Cover.pdf

Roger

 

Edited by RogerH

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You might also make sure the interlocks are in place if you take the cover off. (Put the selector in first gear position and try to move the other rails. They should not move.)

Tom

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Difficult gear changes are most often caused by clutch adjustment.

Bleed the clutch again and again. Air is often trapped in the top of the pipes.

Adjust the clutch so that it has good pedal position at take up. Then get underneath and check pushrod clearance.

If you still have changing issues then look further.

Edited by John McCormack

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I spent years adjusting my clutch and replacing slave cylinders until I discovered that I had a Lockheed bracket and rod and a Girling slave. This was all replaced and the adjustment made as per the book. Now if I press the pedal right to the floor and select a gear, it starts to connect as soon as I move the pedal upwards a tiny distance. I am nervous about adjusting the rod any more.

Thanks Richard & B.

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Just now, Richardtr3a said:

I spent years adjusting my clutch and replacing slave cylinders until I discovered that I had a Lockheed bracket and rod and a Girling slave. This was all replaced and the adjustment made as per the book. Now if I press the pedal right to the floor and select a gear, it starts to connect as soon as I move the pedal upwards a tiny distance. I am nervous about adjusting the rod any more.

Thanks Richard & B.

Clutch bite point should be about half way up the pedal travel so something isnt right there, Does rather sound like that may be some of your problem.

Stuart.

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5 hours ago, Richardtr3a said:

I spent years adjusting my clutch and replacing slave cylinders until I discovered that I had a Lockheed bracket and rod and a Girling slave. This was all replaced and the adjustment made as per the book. Now if I press the pedal right to the floor and select a gear, it starts to connect as soon as I move the pedal upwards a tiny distance. I am nervous about adjusting the rod any more.

Thanks Richard & B.

I find the book adjustment gives too much play in the slave pushrod resulting in the symptoms you describe.

I adjust it so there is just a very little amount of play in the slave pushrod, just enough so that the thrust race isn't touching the pressure plate with the clutch released.

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11 hours ago, John McCormack said:

I find the book adjustment gives too much play in the slave pushrod resulting in the symptoms you describe.

I adjust it so there is just a very little amount of play in the slave pushrod, just enough so that the thrust race isn't touching the pressure plate with the clutch released.

+1

 

Peter W

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How do I know when the thrust bearing is touching the clutch plate ? At the week end I will try some more adjustment but I need to know when to stop.

Thanks

Richard and B.

 

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Adjust with spring removed until there is just a small amount of free play, then replace spring.

Bob.

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Sorry to bring up an old post but please confirm which side of the mounting bracket the Girling slave should be mounted. It has been on this forum before and this time I will print it off.

Thanks

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For Girling, the opposite side to the illustration in the workshop manual is how I remember it.  I spent ages trying to get mine to fit when I was reassembling my car and was on the point of cutting down the pushrod before I worked out that if I mounted the slave cylinder on the other side of the bracket it would all fit.

Rgds Ian

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Like this

image.png.a56b0db730475cdee8cb4112cee2fed7.png

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I was under the car this morning and in my next garage I am investing in a 4 post lift.{maybe}  

I adjusted it a small amount and it was possible to continue turning the rod even after the loose play was removed.So I think I went as far as very little free play. A quick trial around the block and first was very easy to select, fourth was a bit rough but nothing too bad.

I did have the cylinder on the correct side and I too was misled by the manual. The manual that I have  is for TR2, { Lockheed} with a TR3 extra instruction section at the back.

Shall I adjust it further?

Thanks Richard & B.

Edited by Richardtr3a
clarity

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You will find you can push the rod back into the cylinder with the spring removed and there could be plenty of free play left to adjust , yes have another go at it.

 

Graham

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If you could get 1st ok, then the clutch is fuuly releasing as no synchomesh on 1st.

Bob.

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I think that I will leave it all alone now. It is working and the weather is cold and wet. I will save my energy for changing the rear springs to get the ride height to the correct level, in the spring.(:))

I will post another question about this later on.

Thanks Richard & B

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51 minutes ago, Richardtr3a said:

I think that I will leave it all alone now. It is working and the weather is cold and wet. I will save my energy for changing the rear springs to get the ride height to the correct level, in the spring.(:))

I will post another question about this later on.

Thanks Richard & B

Good luck with trying to get the spring eye pins out then!

Stuart.

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I have an answer.  ;)

A long time ago I bought a new TR chassis from The Roundabout Garage in Chiswick. When I got it home the front pins would not move no matter what I tried, and it was brand new. My old rusty body had a large missing part in the sill opposite the front pin. Moores of Brighton had cut it out to replace the drivers side rear spring. I had the body repaired in all areas and two new wings by a TR man who was a milkman and started a TR repair business. He was a long way north from my home and I delivered the body on a trailer. He did a great job.

I mounted the body on the new chassis with stainless steels bolts. A few years ago I needed to replace the front bushes and I removed all the body fixings ,opened the doors and jacked up the rear of the body until it was high enough to give me clearance to slide the entire spring out sideways. It does not have to be very high.

There was no damage to the body and it was quick.

However I am worried about the springs and I am currently planning to have them reset by a specialist in the Midland. They are ST springs and will be made of the correct steel. New springs may be made in China and we do not know the quality of the material.

Any advice please, Richard & B.

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15 hours ago, Richardtr3a said:

I have an answer.  ;)

A long time ago I bought a new TR chassis from The Roundabout Garage in Chiswick. When I got it home the front pins would not move no matter what I tried, and it was brand new. My old rusty body had a large missing part in the sill opposite the front pin. Moores of Brighton had cut it out to replace the drivers side rear spring. I had the body repaired in all areas and two new wings by a TR man who was a milkman and started a TR repair business. He was a long way north from my home and I delivered the body on a trailer. He did a great job.

I mounted the body on the new chassis with stainless steels bolts. A few years ago I needed to replace the front bushes and I removed all the body fixings ,opened the doors and jacked up the rear of the body until it was high enough to give me clearance to slide the entire spring out sideways. It does not have to be very high.

There was no damage to the body and it was quick.

However I am worried about the springs and I am currently planning to have them reset by a specialist in the Midland. They are ST springs and will be made of the correct steel. New springs may be made in China and we do not know the quality of the material.

Any advice please, Richard & B.

Thats the same way I have had to replace pins as well, doesnt actually take that long. Getting the originals reset is a good way to go.

Stuart.

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4 hours ago, Richardtr3a said:

Thanks Stuart. What is your advice on the springs.

Thanks Richard & B.

A good spring remanufacturer should be able to retemper them to restore original height easily then rebush all round.

Stuart.

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On 1/29/2020 at 5:18 AM, Richardtr3a said:

A few years ago I needed to replace the front bushes and I removed all the body fixings ,opened the doors and jacked up the rear of the body until it was high enough to give me clearance to slide the entire spring out sideways. It does not have to be very high.

There was no damage to the body and it was quick.

HI Richard
Just curious about the method of removing the springs... are you saying that you undid all body fastenings, left the doors open and then jacked up the rear?  So in leaving the doors open you allowed the body to hinge slightly as the rear came up?  I may have to do this myself at some point... what is the advantage in allowing the body to flex?

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