Three speed box problem

[Alan]

On the Cotswolds Hills run I started to have problems with my gear change. Top gear isn’t engaging properly- the top gear dogs feel like they aren’t engaging very far and it jumps out of top. There are no ominous noises and it seems worse hot than cold. Anyone got any ideas before I strip it down. My guess is it’s to do with the gate change mechanism rather than the box itself, so I might start by swapping that with a ball change that works on the other cars.

[Charles P]

On the Cotswolds Hills run I started to have problems with my gear change. Top gear isn’t engaging properly- the top gear dogs feel like they aren’t engaging very far and it jumps out of top. There are no ominous noises and it seems worse hot than cold. Anyone got any ideas before I strip it down. My guess is it’s to do with the gate change mechanism rather than the box itself, so I might start by swapping that with a ball change that works on the other cars.

As you observe the first test is to diagnose the box or lever as the source.
I had a gearbox that would jump out of gear with a gate change top, but was fine with ball change. I don't have enough experience to know if that is a common diagnosis or a one off.

Charles

[Robert Foreman]

Alan, 
         as Charles has hinted at it, it is the lid or box. 
I would remove the starter, engage top with the gate change then remove the lid. Take a mirror and torch and you will see how far the top dogs are engaged. 
  This will confirm or eliminate the lid.

[Steve Parkin]

On our three-speed on the RN (ball change) I found the close proximity of the cover on the starter motor sometimes made it difficult to select top. Required a bit of judicious fettling with a file!

[AustinWood]

Could be the detent springs

[Dave Mann]

I'd remove the gearbox top to see what's going on. I had one where I couldn't make a change from first to second without a noise it turned out to be worn interlocks allowing another gear to start engaging ( I can't remember which)     

[Alan]

That’s what my money is on, Dave. Will be looking at it later today. V

[Alan]

Sorted. There was a bit of play in the sliding bar, but mostly the gate change selector has too much play and after the lost motion is taken up the top gear dogs don’t engage as far as the detent. It works fine wit a ball change top. Actually I think I prefer it to the short lever.

Now then, the ball change I used comes off the Ulster and it wants it back. I have a spare top but can anyone help me with a 3 speed ball change lever.

[Charles P]

Sorted. There was a bit of play in the sliding bar, but mostly the gate change selector has too much play and after the lost motion is taken up the top gear dogs don’t engage as far as the detent. It works fine wit a ball change top. Actually I think I prefer it to the short lever.

Now then, the ball change I used comes off the Ulster and it wants it back.  I have a spare top but can anyone help me with a 3 speed ball change lever.

I have a whole ball change top, bit tired and needs the "ball change rebuild " process. It has been chopped down and adapted to Ulster size.
I'll conjure some photos

Charles

[Alan]

Charles. Thanks but I have one of those - it’s an unmodified stick I’m after.