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Hi All,

Yesterday I was really looking forward to a day out with the local Lincs group, but I hit a problem as soon as I tried to reverse out of the garage. And it was my birthday (that was for the sympathy vote).

The gear lever felt a bit strange but went it into reverse. The car then wouldn't move backwards and I immediately assumed I must have left chocks under the rear wheels, which I hadn't. I tried to select other gears but the lever would not select any other gear than reverse (and neutral). I have had a similar problem before and solved it by taking the gear lever out and levering one of the rods back into position with a large screw driver, I thought it was just a freak occurrence and the car has been ok after that until now.

The pic below shows what I found when I took the cap off. I was again able to lever the right hand rod back to the neutral position, but this time I think I need to try and get to the bottom of the problem.

I'm assuming my next move should be to take the top cover off the gearbox - but I've got no idea what I should be looking for. Are there any obvious components that may have suffered wear (or breakage) that could cause this?

Thanks, Ali.

 

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Hi Ali,

that looks as if it has selected 1st gear  !! :blink:

IT could be the interlock that in theory safe guards the selector rods from selecting more than one gear.

Two small ball bearings and a short rod.  I can;t see how this would come adrift in normal use but if somebody has been at the GB before you then it may

have been assembled badly..

You need to take the top cover off and strip it all down.

Wait for other reasons before diving in.

Roger

 

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Hi Roger,

I think I must have put it in first whilst moving the gear lever around before getting reverse - I sometimes have to play around with it a bit.

Immediately after the problem the gear stick could only find the neutral and reverse positions - and the neutral position only felt as if it was between 3rd and 4th and not 1st and 2nd. So I think that is supported by the position of the selectors. But how could the end of the gear stick have got out of the 1st/2nd gear slot? I assume that 2nd and 3rd appeared rock solid because it was already in 1st, but why was I apparently able to move it into the reverse position? And in that reverse position the car would not move as I let the clutch up - but there was resistance. In 'neutral' I could let the clutch up (even though after taking apart it was apparently in 1st).

I hope I'm getting this right - I feel like a witness trying to remember a crime, and we all know that they can easily get it wrong!

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Hi Ali, 

    As Roger has said the top of the gearbox needs to come off and be checked. As pointed out, there are some ball bearings located on the three shafts that are there for safety, stopping you selecting more than one gear. I suspect like Roger has pointed out that there is something missing here. It's a top of the box off and strip down to check. 

Neil

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I does sound as if two gears were selected at the same time. The fault will be on the top cover, which is relatively easy to get off.

Bob

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Thanks for your replies.

I took the selector mechanism to bits and found that the 'interlock dowel' (Rimmer) was missing (as was suggested could be the case)! This is also called 'interlock roller' by Moss and sits in the horizontal hole through the 3rd/4th gear rod. At first I looked at this mechanism and thought the dowel wasn't really required (perhaps whoever assembled it last also thought this), but then I realised its job is to keep the 'interlock ball' apart by the right distance so they can do their job (correct me if I am wrong).  By my reckoning that would allow the 1st/2nd and reverse rods move at the same time, which is exactly what my problem appeared to be (though it's still a mystery how the gear lever end allows that to happen).

Whilst at it I also noticed some other strange things that may be right or wrong - perhaps someone knows?

i) The 'detent' mechanism on each rod is a plunger (see pic) - Moss seem to indicate only Reverse is a plunger and the other two balls, whereas Rimmer shows Reverse and 3rd/4th as plungers and 1st/2nd as a ball ?? The existing ones are a bit worn, so I need to get new ones - but balls or plungers?

ii) The part of the selector forks which activate the overdrive switch balls appear to be strangely worn - as far as I am aware it works ok, but it almost looks as if the forks were not designed to operate those balls (see pic).

iii) The neutral indent on the 3rd/4th rod is very small compared to the 'in gear' indents, and the neutral on on the 1st/2nd  and reverse rods. I assume it is supposed to be like this, but seems a bit mean - any idea why?

Thanks all, Ali.

 

 

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Edited by Ali King
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2 hours ago, Ali King said:

Thanks for your replies.

I took the selector mechanism to bits and found that the 'interlock dowel' (Rimmer) was missing (as was suggested could be the case)! This is also called 'interlock roller' by Moss and sits in the horizontal hole through the 3rd/4th gear rod. At first I looked at this mechanism and thought the dowel wasn't really required (perhaps whoever assembled it last also thought this), but then I realised its job is to keep the 'interlock ball' apart by the right distance so they can do their job (correct me if I am wrong).  By my reckoning that would allow the 1st/2nd and reverse rods move at the same time, which is exactly what my problem appeared to be (though it's still a mystery how the gear lever end allows that to happen).

The interlock works as  - when you select 1st gear, it's rod pushes its ball into the  'interlock roller' which holds the reverse ball hard into the reverse rod - it can't move

If you select reverse, it's ball  pushed the 'Interlock roller' which pushes the 1st gear ball hard into the 1st gear rod - it can't move

The same for 3/4th gear. When it moves it pushes bith balls out into their own rods - they don't move.

Whilst at it I also noticed some other strange things that may be right or wrong - perhaps someone knows?

i) The 'detent' mechanism on each rod is a plunger (see pic) - Moss seem to indicate only Reverse is a plunger and the other two balls, whereas Rimmer shows Reverse and 3rd/4th as plungers and 1st/2nd as a ball ?? The existing ones are a bit worn, so I need to get new ones - but balls or plungers?

1/2& 3/4 have balls. Reverse has a pointed plunger - ignore Rimmer for all things.

ii) The part of the selector forks which activate the overdrive switch balls appear to be strangely worn - as far as I am aware it works ok, but it almost looks as if the forks were not designed to operate those balls (see pic).

Normal wear - it will last for many years.

iii) The neutral indent on the 3rd/4th rod is very small compared to the 'in gear' indents, and the neutral on on the 1st/2nd  and reverse rods. I assume it is supposed to be like this, but seems a bit mean - any idea why?

That's what TRiumph wanted - it doesn't need to be any bigger

Thanks all, Ali.

 

 

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20210727_125019.jpg

20210727_125810.jpg

20210727_125818.jpg

20210727_142332.jpg

Roger

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A previous owner had been juggling the balls and plungers on my gearbox, It used to jump out of third on the over-run. IIRC the grooves in the shaft for the plungers and balls are different widths and as a result mixing them up meant they wouldn't grip properly. Putting them back in the correct places fixed that problem.

I also used to get the two gears selected at once problem, further investigation (many years later) revealed the interlock plunger was also missing and was fixed by fitting one from a spare top cover I happened to have lying about.

Neil

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1 hour ago, RogerH said:

Sometimes the 'interlock  roller' can innocently fall out when rebuilding the top cover.

I always keep it in place with some thick grease whilxt getting the balls in place followed b the rods.

 

Roger

Roger, I think you've written that somewhere else on the forum as I remember reading it fairly recently when I was doing this job and followed this as well.

Ali, 

Its's a little fiddly but far less scary than it all sounds with regards getting everything back in and in the right place. I guess the risky bit of undoing the square bolts on the selectors without snapping them has been done to get to the stage you are at so it's all just reassembly. Good luck and it sounds like you have found the problem. 

Neil

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  • 2 weeks later...

Just an update...

I needed a new interlock dowel (which was missing) and a new spring and ball for the 1st/2nd detent, and used the two good plungers and springs for the other two selector shafts. I suspect I should have replaced one of the other plungers for a ball, but the suppliers diagrams were all a bit different and I went with the Revington one in the end.

Rimmer had the dowel but not the spring, Moss had the spring but not the dowel. Rimmer is down the road, so dowel from them. Moss wanted £4.60 postage for a £1.80 spring, so got it from Revington who just charged postage at cost (thank you).

However, the spring with the ball appeared too long and was nearly coil bound when the grub screw was flush with the cover surface, so I hacked a piece off it and re-tried (any pretence to doing a precision job and measuring the force to pull the selector rod a la manual was quickly abandoned). When testing the gear stick on the bench it seemed a bit stiff, by I reckoned it would probably feel better in the car than being too sloppy - and it did).

Rooky error I think, when re-fiiting the gearbox cover the reverse lever kept moving forward into reverse position when I wasn't looking, so first time I assembled it it had the selectors in neutral and the gerbox in reverse!. I won't do that again.

The only other problem I had was that the little anti-rattle plunger in the gear stick seemed to be catching on the selectors when moving the stick between the different selectors in neutral. The selector rod grooves appeared a bit worn resulting in a little step between them, and the plunger also appeared to be a bit worn and was catching the liitle steps. It seemed to me that even a new plunger would give the same problem, so although it was in before, I've just abandoned it now to see how it goes.

So I've just had my first test drive (no transmission tunnel - a bit unerving watching the prop-shaft whizzing round a few mm away!) - and it all feels good, gear selection feels a lot better and positive, so hopefully problem solved and no multiple concurrent gears selected in the future. I'm hoping, and assume that, if the gear stick doesn't rattle I can get away without re-fiiting the little spring and plunger.

Thanks all for your input, it does help with confidence when taking on these new (too me) jobs.

Ali.

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Hi Ali,

 if yu do get round to fitting the anti-sizzle spring/plunger then use a plastic tie wrap to compress the plunger as much as possible.

Align it very close to its final position and then whack it into place. The spring/plunger will go down/in and the plastic tie wrap will be left behind.

Cut this away.

 

Roger

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I drove for more than 25 years without any anti-rattle spring & ball in the bottom of my gear lever - never worried me.

Pete Cox supplied the parts earlier this year when he repaired the box, and, with some vaseline to hold the spring & ball in position, it's now an anti-rattle box! 

However, to be honest, I haven't noticed any difference.  It is, of course, rather a noisy car, as grandson Ben (aged 9) told me when I took him for a ride recently - and he said the ride was hard (it is).  He watched the speedo, which is mounted next to the Halda on the left, and informed every time it passed 60 - but it over-reads (yes, truly) and wanders quite a lot.

Ian Cornish

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i will be interested if things change after you fit the gear lever rubber gaiter. I suggest that you fit it and trial things before fitting carpets. My gaiter was so stiff that  it inhibited reverse selection.

Rod

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