Strange bolt in top of ABH gearbox

[ctange]

What is the function of this bolt in top of the gearbox with code: ABH

It is too short for being an oil dipstick.

[rsxsr]

Put it back. It is part of the gear selector barrel. It keeps the barrel centered.

[ctange]

Ok, I will put it back.
Hopefully I have not caused any loss of adjustment
by taking it off.

[rsxsr]

As long as you were not working the gears with it out, you should be fine.

[ctange]

As long as you were not working the gears with it out, you should be fine.

But that was exactly what I did. I vent through all gears, and turnede the driving axels to se if there was any effect. At some point the bolt would nu screw down, an I worked some more until I could get it in by my fingers.

[rsxsr]

You should be ok. If you removed the shifter assembly, you could see how it worked. The pin goes in after you install the assembly. No worries. Make sure you can find all the gears with the pin in and you should be ok.

[ctange]

Fortunately I can find all the gears.

The gearbox is heavily corroded on the outside,
by galvanic corrosion in the aluminum around the
steel bolts. Therefore I have had all the bolts out,
did some grinding, and put them in again.

But is is not clear from the outside what this last bolt do,
and therefore I did some experimentation, without becomming wiser.

I look forward to have at look inside one of these
gearboxes someday.

I have a 5 gears 3H box, where I can not use
1. and 2. gear, they slip out of gear with the
slightes load, so I will open this in the near future.