Eliminating the Speedo Drive from the Transmission Case

[docc]

In the gearbox assembly section (N) of the 1999-2001 Workshop Manual, Page 24, I see:

    " Fit the odometer transmission:

•  Position the shimming washer using the special tool;  "

[docc]

And the Workshop Manual, Gearbox Disassembly N/3, page 4 (last step of 14):

"Remove the odometer transmission "Q" [pictured bottom right of page 5]

and keep the striker washer positioned inside the gearbox."

(emphasis added by this poster.)

So, yep, that little booger is down in there. Don't let it ruin your day!

[docc]

[Kane]

Egad! I think I am beginning to understand Rolf’s warning.

Thank you!

[Kane]

18 minutes ago, docc said:

docc, thank you very much for this illustrative post. It’s really helpful to see that part out of the gearbox. Things are much clearer now. 
 

[docc]

That "odometer transmission"/"odometer gear" (GU04762500) looks to be an assembly of five parts: the screw-in "housing", gear driven shaft, two thrust/shimming/striker washers, and the gear that drives the shaft. 

That last one . . . I guess mine is still rattling around in there . . .

[cash1000]

6 hours ago, Rolf Halvorsen said:

This is a complete kit! A new cable and special adapter is included! This will completely replace the always breaking angel drive!

I can say that new cable works fine. I had to slightly bend the metal tube at the gear box end so it had clearance around the rod between the 2 fuel injection bodies

[Weegie]

Think it's already pretty clear and I'm not familiar with the 6 speed boxes, but the 2 washers AFAIK are shims and there to take up thrust loading on the helical drive. I don't think they are available as components separately.

What happens on the 5 speed boxes, is the lower washer gets left in the bottom of the hole.

The helical drive (the thrust washers locate on the top and bottom of that drive) are driven from a worm on the layshaft and is behind the main layshaft bearing. In order for the worm on the layshaft to drive the helical gear there is a cutout in the gearbox casing. If the washer is left in place vibration can (and usually does) allow the washer to move, it then gets caught on the helical drive.

If you're lucky it get spun out into the bottom of the box where the chances are it won't do any harm and either get flushed out during an oil change or caught by the magnet.

If you're unlucky it gets mashed and the pieces migrate into the large ball bearing supporting the layshaft and damage/deystroy it, or it slips further in to get mashed and grind away at the gears. Neither scenario will be inexpensive.

The only reasons I can think why Rolf states to leave the assembly in there, are the already explained danger, or sealing to prevent water ingress. If the washers are removed and a flat rubber ring or even O ring used on the plug to eal it, then all should be good.

My 1100 sport runs SpeedHut gauges and I removed the Gearbox internals, not had a problem.

[Rolf Halvorsen]

The special wascher are hardened steel waschers of 1,0mm thickness. (You can get them with a magnet)

1,0 + 1,0 = 2,0    (I have bought about 100 of these - so contact me if you need some).

Since the inner and outher diameter are close to identical with a standard 6mm washer - DO NEVER USE ONE OF THEM!

The standard wascher are 1,2mm thick. 

1,2 + 1,2 = 2,4

THIS WILL SQUEESE THE AXLE SO THAT IT CANNOT ROTATE!

5- and 6-speed gearboxes uses the same technic, but the axle has different number of tooths.

[docc]

The gear that drives the vertical shaft (bottom pointer of #5, is that the helical gear?), is left in my gearbox to spin, but with nothing to engage.

Is it rattling around?  Like a blender blade in a margarita mix?  

[Kiwi_Roy]

I used the drive to spin a magnet activated reed switch for a pulse input Speedhut.

[Weegie]

14 hours ago, docc said:

The gear that drives the vertical shaft (bottom pointer of #5, is that the helical gear?), is left in my gearbox to spin, but with nothing to engage.

Is it rattling around?  Like a blender blade in a margarita mix?  

No @docc It's is fixed onto the Layshaft.

The worm has a small cutout and a steel ball, like a ball bearing fits into the cutout. The lower section of the ball fits inside the deepest spline on the layshaft so the collar containing the worm drive can't go anywhere and is forced to turn with the layshaft.

If you think about it, it would really have to be that way as the worm drive will have a load exerted onto it by the vertical helical gear, if it wasn't positively located it would slip and not rotate at the same RPM as the worm.

Dunno if this helps to show the collar located onto the layshaft. Behind the collar, the slotted section between the gear and the collar is where the layshaft bearing installs onto. This is a 5 speed drive but I think the 6 speed is similar

The ball, in turn, is held in place by the Layshaft nut which butts up against it (not shown in the picture but you can see the threads it screws onto)

 

EDIT

Just to add the worm drive has to stay whether you like it or not. The smooth surface on the collar behind the worm drive is the surface that the layshaft oil seal runs on

[Rolf Halvorsen]

12 hours ago, docc said:

The gear that drives the vertical shaft (bottom pointer of #5, is that the helical gear?), is left in my gearbox to spin, but with nothing to engage.

Is it rattling around?  Like a blender blade in a margarita mix?  

For the 6-speed gearboxes it has a similar locking mechanism. So you can just leave it - it will make no problem for you.

Edited February 16, 2022 by Rolf Halvorsen
writing error

[Rolf Halvorsen]

Please help me. I am too old to know how to increase the picture.

[docc]

You can post images from a hosting site (I prefer imgzeit because I know the developer), or create an Album in your profile and add images to it that appear in the Gallery. "Copy Image Link" from the thumbnail in your album catalog and paste into your post.