tr3a Accelerator linkage.

[Richardtr3a]

There are only a few areas of my 3A which I have never dismantled.

 

After my son-in-law drove the car he noticed that there was a lot of movement on the pedal before the actual lever moved. This makes the pedal close to the floor.

 

How does the shaft attach to the lever? It looks like a pin in the Moss catalogue. If it is, my lever or shaft are worn and will need repair. Is it possible to work on this connection with the gearbox cover in place? How could it be repaired.

 

Please give me your advice.

 

Thanks Richard & H.

 

[iain]

HI Richard

 

its probably a combination of issues, the biggest I would think is that the nylon bush on the throttle peddle shaft as it goes through the bulkhead sidewall wears over the years. Check this first and then check each articulating point for free play. The next most obvious is the fulcrum mounted below the front carb.

 

Iain

[Lebro]

The two rods in the system have adjustable ends. you may simply need to shorten one or other of them to recuce the lost movement. You should have some free play though, the throttle stops on the carbs need to work to set the idle speed, not the linkage.

 

Bob.

[Richardtr3a]

Thanks for the advice. My lost movement appears to be at the point where the shaft joins the lever which has the return spring. The Moss catalogue shows a pin and there must be a lot of lost movement.

 

I am planning not to dismantle any thing but to take out the gearbox cover(again) and fix the pedal in the upright position nearly level with the brake pedal. Then I could drill a hole in the lever and fit a new roll pin with loctite.

 

I should have repaired this last time the engine was out

Edited May 6, 2017 by Richardtr3a

[TR 2100]

Richard,

 

No-one seems to have said that removing the mills pin

in the accelerator rod/lever is an absolute PITA. And

that's with gearbox removed!

 

It's a slightly tapered pin that needs to be knocked out

from underneath.

Sensible guys, once it's removed, fit a different style of

pin that can be tapped in from the top but tapped through

and out of the bottom. I should be able to remember the

name for this kind of pin - but can't!

 

I can't see that there can be much, if any, play in that area.

 

AlanR

[Richardtr3a]

Thanks for the warning before I start.

 

Is it possible to drill the mills pin out from underneath ?

 

Would it be possible to leave the mills pin in place and drill a new hole for a modern roll pin from inside the car 3mm in stainless steel. ?

 

Maybe the mills pin is hardened steel?

 

Thanks Richard & H.

[BlueTR3A-5EKT]

Yes a roll pin is an ideal solution.

 

I also suspect there are cable linkage conversions ou there because removal/replacement of the Mills pin was such a challenging task.

 

Peter W

[RogerH]

Hi Richard,

firstly make and attempt to remove the existing pin. It should be quite a hard material. However you shouldn't have to drill it.

 

The Moss WebCat http://www.moss-europe.co.uk/shop-by-model/triumph/tr2-4a/fuel-system-induction-controls/engine-controls/accelerator-pedal-fittings.html

shows a roll pin, but that is probably the aftermarket spare.

 

I wouldn't try to drill another hole with whatever pin is installed.

You may well break the drill off and make a dogs breakfast of it.

 

I wouldn't even consider a stainless pin in a shear position.

 

Roger

[Richardtr3a]

Hi Peter,

 

Thanks for the advice. I searched Google for Mills Pin and found a thread on the forum from a few years back. The 4A owner had a bad time.

 

I am trying to find another an alternative answer to removing the Mills pin, which would be difficult if I have to lie under the car and drift it out. It has been there since new and there must be significant wear so a replacement pin will not help.

 

I am thinking of drilling a new hole in a new position and using a roll pin. I suppose that it should pass right through the lever and shaft, and that means through the Mills pin also.

 

Is this possible?

[RogerH]

Hi Richard,

to add to my previous post.

It should be possible to remove the whole pedal metal work. If you do then you can sort it on the bench.

This may seem like more work but you will get a better job done and possibly quicker than laying under the car.

 

Roger

[Lebro]

You can only remove the whole aasy if you first remove the pin in question !

 

Bob.

[Graham Harris]

If its that floged out i would think you can tap it out from the top the taper isn't that big and the pin isn't case hardened. I wouldn't have thought you would need to take the gearbox cover off, isn't the shaft and leaver on the engine side of the firewall?

 

Graham

[RogerH]

You can only remove the whole aasy if you first remove the pin in question !

 

Bob.

Bu99er!!!

I thought, with the nylon bearing and cover plate removed it would come through.

 

The lever is in the engine side of the bulkhead.

 

Roger

[BlueTR3A-5EKT]

Richard, I have just raked through my odds and sods. I have a 4 mm dia hardened roll pin (What I use 2 of in gearbox release bearing forks) and a 1/8" (3.3mm ) solid Mills pin. Both are just under 1" (25mm) long

 

PM me and I will drop them in the post.

 

Peter W

 

PS Knocking the old pin out will need an assistant to support the opposite side of the lever as you whack at it with a pin punch. Stout block of wood would do.

 

Is the pin flush fitted top and bottom in the lever?

Is there enough pin head sticking out the top, that you couldgrip with Vise Grips and pull?

Edited May 6, 2017 by BlueTR3A-5EKT

[Richardtr3a]

Hi Peter.

 

The pin is flush with the lever. I have spent a couple of hours cleaning it all up this morning and the wear is in the shaft. If I replace the pin the wear will still be there.

 

How about drilling an entirely new hole next to the pin and installing a new pin in fresh metal. It is impossible to drive it out from underneath and if it is tapered and hardened it will be very hard to drill it out. I can see the bit breaking and sliding away from the hardened part as I push down from on top.

 

Would a new hole weaken the lever. It looks quite strong.

 

Richard & H.

[BlueTR3A-5EKT]

A new pin in a new hole could well be your solution.

However....

The mills pin I have is not what I would call hardened. If you can centre punch the top of the old pin, lock the shaft and lever from moving; you should then be able to drill the old pin to 1/8" max diameter and depth to start with.

Once you have drilled in 1/8" you should be able to punch the remaining bit of pin out - Remember it has sheared and may not be in line - Do not keep drilling or you risk creating a figure of 8 hole in the shaft!!!

 

If you go over 1/8" diameter have the 4mm roll pin avaialble, that you can squeeze into place with grips. Just open the hole out to suit, once it is all on the bench.

 

To me the difficulty could be perpendivcular access with a drilling machine, I guess a Dremel type drill would fit in there OK.

 

Once the pin is out and the lever is off it would be worth investigating and/or renewing the self aligning bush. Moss sell them (058282) at £8.00. I would be tempted to bore and bush it myself with a thin wall Phosphor bronze item or bit of nylon. but I am a cheap-skate.

 

Peter W

[stuart]

If you disconnect the forward rod from the bracket and the spring then the pedal should go to the floor and allow easier access to the bottom of the pin to be able to drive it out. An 1/8" rivet shank used as a drift will help. You may find removing the rear carb will help enormously

Stuart.

[Richardtr3a]

I have been assuming that the loose movement was due to wear. It has never been touched since new. If it is broken then I can see that the removal is more complicated.

 

I am considering a fresh hole drilled from above. Will this weaken the shaft? It looks as if it could cope. Then I could fit a modern roll pin.

 

It is a good tip to remove the rear carburettor. I will start this on Thursday after the car ,with hard top, comes back from the sidescreen welder prior to recovering. Another plan which may pay off, or not.??

 

Thanks

[Lebro]

If it's any help, my linkage was also "loose" in this area, turned out there was no pin ! just rust etc holding the lever in approx the right place on the shaft.

It would allow movement of around 10° but would then bind. Now firmly pinned ('fraid I can't remember what I used - may well have been a roll pin.)

 

Bob.

[Graham Harris]

If you can't get the pin out which may be broken , a bit of up and down pressure on the crank could be enough to brake the remaining pin and it should come off. If the hole in the shaft is floged it will need filling and redrilling on the bench .

 

Graham

[Richardtr3a]

I will have trouble getting it off the car because the bolts retaining the shaft have not been loosened since 1958.

 

I am still dreaming of a 1/2 hour job drilling a new hole and using a modern roll pin.

 

Always hopeful

 

Richard & H.

[BlueTR3A-5EKT]

Soak with 'Plus-Gas' today.

Tomorrow - Grip the nuts in the cages with vise grips held by an assistant as you use a socket on the screw hexagon head in the footwell.

Peter W

[Richardtr3a]

There is some progress. I made up a small punch and the mills pin has moved a small amount. It looks as if I can get the lever off if I carry on. Once the lever is removed it is obvious that the shaft bush should be replaced. there are two plates supporting it which are held on by 4 screws. There is a lot of paint and i can not find a socket to fit. I have tried my usual sockets,

 

If any one can guide me it would be very helpful. They have been fitted from the engine side which makes it very cramped and Mole wrench etc. will not work.

 

Thanks Richard & H.

[stuart]

If they are original screws they will be 2BA

Stuart.

[RogerH]

Hi Richard,

there should be 4 self tapping screws holding the bearing plates from inside to out.

 

Have a closer look and remove some paint if necessary.

 

Good luck

 

Roger.

 

PS - just spotted Stuarts post. Moss show self tappers.

Edited May 13, 2017 by RogerH