Quadrant / Pinion

[RoyC]

Did you take any pictures while you were in there? It would be very helpful to see the tooth forms for both the quadrant and the pinion. Do you recall if both were pointy, flattened off, or one of each?

Richard L.

Sorry, no pictures, I don't own a mobile phone.
Both quadrant and pinion had pointy teeth, same as the ones that I took out.
I purchased both quad and pinion together from Andrew @ Priory magnetos.

[RoyC]

I have just popped down the garage to have a look at the ones that I took out and it is hard to tell what the original profile of the pinion was as it is badly worn but the quad looks pointy and in good condition.

[duTch]

 Good that you've had a win, but probably best address this bit;

 

.........and all the parts feel like a nice fit all except for the stop, that is a little wobbly. ....

[trevinoz]

As Dutch said, you REALLY need to fix the sloppy stop.

[chaterlea25]

Hi,
Here is a link to my solution for damaged stops
https://www.a7a10.net/forum/index.php?topic=2914.msg19637#msg19637


John

[RoyC]

I looked at the stop but couldn't see how it was held in.

Could this pinion with the flat ends give me a better result ?

[JulianS]

Roy

The photo shows the nut on back of the inner cover which retains the stop. They come lose and the stopped elongates the hole hence the rocking.

The solution in the above post by Chaterlea25 is first class.

[RoyC]

Roy

The photo shows the nut on back of the inner cover which retains the stop. They come lose and the stopped elongates the hole hence the rocking.

The solution in the above post by Chaterlea25 is first class.

Thank you Julian.
Is it as easy to take the back cover off and replace as the front cover ?
Also, what are your thoughts on the alternative pinion gear ?
I agree, Chaterlea25's solution is superb but I don't have the machinery to do that sort of job. Hacksaw, small pillar drill and files is my workshop.

[duTch]

 

Is it as easy to take the back cover off and replace as the front cover ?

 When you had the nut off the mainshaft, you were almost there. Just needed to pull the biscuit/sandwich plate/ inner cover out Just ensure it's in neutral- but can still be done later with some difficulty.
 also need to be aware of layshaft end-float, and not bugger the gasket, or have a replacement or materials at hand

[JulianS]

Not as easy as the outer cover.

The mainshaft is usually quite tight in the ball bearing in the inner cover which can make it quite difficult to pull the cover off the mainshaft (and to put it back on again) Avoid blunt force because of the selectors. If you are lucky it will pull straight off but not with my box!

My preferred method is to take the clutch off then the inner cover with mainshaft can be pulled out, after removing the single retaining screw. The stop can then be attended to.

This aso allows you to check the oil seal behind the gearbox sprocket.

I had my stop repaired by build up with ali weld and re machined but if there is a next time I will go for the Chaterlea25 method.

[RoyC]

 

Is it as easy to take the back cover off and replace as the front cover ?

 When you had the nut off the mainshaft, you were almost there. Just needed to pull the biscuit/sandwich plate/ inner cover out Just ensure it's in neutral- but can still be done later with some difficulty.
 also need to be aware of layshaft end-float, and not bugger the gasket, or have a replacement or materials at hand

Sorry to be such a PITA.
By gasket, I assume that you mean the main gasket between the gearbox case and the back plate ? if so, got 2 on order.
Do all of those bits that I can see in the parts catalogue stay put when I remove the back plate ?

[Topdad]

Roy, the inner cover is held in place by one countersunk screw on the top to the right as you look at it ,check the 2 dots on the gearchange plate are lined up that should be neutral and then wiggle the cover off, as you pull it off the gear change plate will drop thats normal, refit holding gearchange plate with the dots lined up honestly it isn't as complicated as it sounds.

[duTch]

 Jules- I don't discount what you say, but with the nut on the shaft it should come reasonably easy with a tap from a rubber/rawhide/copper/ soft mallet, and pressure on the inner cover from behind- (if yea kenows what ah means)...and hold yer tongue right

 I know it's nice to look at stuff like clutch to check it out, but if no need why do?

 Topdad rounded me up;
 

Roy, the inner cover is held in place by one countersunk screw on the top to the right as you look at it ,

 been a while since I had to deal with them and still don't remember

[RoyC]

Thanks to all of you lads.
I am feeling a little more confident after all this advice.
I have put a couple of things on order and when they arrive I will have a go at it.
I am having a little difficulty locating a locking washer for the pivot nut.
Thanks
Roy.

[JulianS]

Yes it does make sense to minimise the work to that which is necessary.

If the wobble in the stop is not too much it might be worth trying to tighten the nut. You need to check that the plain section of the stop is not preventing the nut from being tightened fully.

With outer cover  removed, grip the stop with your chosen tool, there is just enough space to get a spanner on the nut if you go in under the swinging arm to back of the box (just tried a spanner on my A10 - and yes the nut is a bit lose)

If it tightens OK then you may need go no further, if not another solution may occur to you - with my lose nut I am thinking a suitable grade of loctite between diameter of case and stop.

If cover does come off OK then everything should stay in place in the maincase - the mainshaft may move out a bit but should just push back and the large pinion on the layshaft will just lift off and goes back on just as easily.

I hope neither your or my stop looks like the photo of one I took out a few years ago.