Speedo Drive

[Scout63]

When I rebuilt my G5 I installed an electronic speedo so I did not install the speedo drive ball, hardened washers and drive gear when putting the gearbox together.  I capped the drive housing with a speedo fitting blocked with some JB Weld. Now I’m converting the gauges back to stock T3, and need to install the parts so I can run a mechanical speedo cable.

How far back do I have to tear it apart to install the ball and drive gear.  If I remember correctly, I need to remove the layshaft end nut to pull the speedo worm drive and install the speedo drive and ball.  This means getting the swingarm and drive shaft off.  Can I remove and refit the end nut without pulling the gearbox?  That would mean crabbing the frame which I just don’t want to do for a fourth time...

Thanks as always.  Ben

[Old Jock]

Hi Ben

I've removed the layshaft nut (and lock tab) a few times without removing the endcase and yes that could all be competed without removing or opening the box.

I'd imagine though it will be a bit fiddly with the box lying horizontal though and you'll need a deep socket, but you'll have that if you've been into the box already.

How did you secure the worm drive without installing the ball which retains the worm drive and seal runner?

When I did something similar when eliminating the whole mechanical speedo drive on a Sport, I left the locking ball in place to ensure the worm drive and seal ring (all one part) turned with the layhaft.

I just removed the top part of the drive; the angled gear, washers etc: and capped it.

I ran the speedo pickup off the back wheel

John

[Antietam Classic Cycle]

The speedo drive worm really wouldn't need to be removed to insert the driven gear. However, you either need to install it without the lower hardened washer or somehow very carefully put that hardened washer into place first. Without the lower washer, the speedometer may be a bit more erratic, but that's likely the only side effect.

[Rolf Halvorsen]

1 - Put a long thin steel rod into the hole for the lower hardened washer, to act as a guiding pin.
2 - Enter the lower harden washer with the help of the guiding steel rod. Put some grease on the side that is down so that the washer stays in position.
3 - Enter the speedometer wheel with the upper hardened washer, but without the brass housing.
4 - Enter the brass housing.
5 - Job done.

[Scout63]

Amazing responses from the A team.  Thanks so much.  Ben

[snobear]

Can I simply remove the speedometer drive and lower washer and install an M16 plug in its place or does the worm hold something else in place?

[Old Jock]

Others may have a different opinion but I'd say yes you can

The drive assembly is driven off a worm drive on the layshaft, which also acts as the endcase seal runner, but removing the bevel drive and washers, would have not impact anything else AFAIK. It's what I did on my 1100 Sporti and over a 1k miles later there hasn''t been any problems

[Scout63]

You can just cap it off. That’s what I did. When I went back to a Speedo drive I was able to install the drive ball and Speedo drive with hardened washers without removing the gearbox.  It took a skinny magnet to lay the ball in and grease on the Speedo drive to hold the washers.