speedo drive.

[cowboy5]

i just bought a new speedo cable, the other one was really bad. guy at yamaha said to check and clean the speedo gear drive. is this hard to do and how do i remove it. do i need to take off the front wheel. should i just try the new cable and see if it works. i get the cable on tuesday. not a long wait

[prometheus578]

'Wearing your new speedo's"

Several options here.
Remove the front wheel, inspect the gear area and regrease as needed then replace the cable.
Now.. depends on why the cable was defective in the first place.
Kink or break in the outer sheath somewhere? rusted and snapped?
Easy on our bikes to replace the whole unit, I mean.. the whole cable as a unit.
One some bikes, with odd fairings or inaccessable speedometers, the old trick is to pull the inner cable out of the sheath, and slide the new inner cable up into the old sheath and then reconnect everything down at the wheel.
Do as you see fit.
I'd replace the whole thing...as you have it anyway.
I mean... what would you do with a left-over hard plastic piece of hollow tube, other than beat your children... as they have failing grades and may not graduate next month.
Our mechanical and parenting skills may be different, I don't know.

[Jerry]

To service the speedo drive you need to remove the front wheel. The drive unit is quite simple; a gear on a shaft turns a hollow worm gear; the end of the speedo cable fits inside the worm gear and thus transfers the tire's spinning motion into a twisting motion which then goes through the cable to the speedo head.

The main gear on its shaft is what needs to be greased. There is a snap ring that holds the gear in place. Remove the snap ring, pull the gear, grease the shaft, and replace the gear and snap ring. Once you have the drive off the bike it is a 10 minute (or less) job.

I don't think a 'dry' shaft would damage the cable. There is nothing in the drive assembly that would put a bind on the cable, causing it to be under stress.

In my case, the shaft was dry to the point where the mechanism was "squeeking" (making a sound) that took me a bit of time to track down. I make it a point now to grease the drive whenever I change front tires, which is about every 12K - 14K miles.

Wile you have the front wheel off, the other part of the speedo drive should be checked. This s a thin plate with 2 tabs or ears on it. This plate is between the drive and wheel and is used to spin the speedo drive mechanism. Very common for one or both ears to break off, causing the speedo not to work or work erratically. When you reassemble the front wheel and drive make sure you get these components fitted together correctly.