Topic: CB750 F2 Speedo Drive

[CB750F2]

I have a excessive fore and aft "play" in the worm on the speedo drive. How do I remove this worm from the drive. I have removed the drive from the bike. On the early Ks this worm can be removed by first removing the end cover but the drive on the Fs does not have this removeable end piece. If I remove the oil seal first there may be a circlip behind the seal that holds the worm in place. Can anyone help with this? Thanks, Pat from Australia.

[gregimotis]

Although I haven't torn into the drive yet, I have speedo problems in my F1 which I suspect start in that area.  Would love any information.


/bump

[CB750F2]

Greg, thanks for your reply. I hope some one will reply with the the required info. Pat

[CB750F2]

Greg, I couldn't wait any longer so I "bit the bullet" and had a go. I drilled a hole approx 4mm in diameter through the front end of the gear housing and then simply knocked out the worm with a punch - after removing the gear first. This also removes the seal without any damage to it. I then tapped the hole out to 5mm so that it can be plugged with a 5mm grub screw after reassembly. I added a couple of shims to remove the excess play and re-assembled. It may be also a good idea to add another grub screw to hold the rear worm bearing in place - I haven't done this yet. Hope this helps. Pat

[CB750F2]

Greg, I have refitted the speedo to the bike and taken it for a test run. I am happy to report that most of the erratic movement of the speedo indicator has been eliminated. The indicator used to fluctuate +- 15 kph now the fluctuation is down to +-2kph. I can live with this until I get round to replacing the speedo and tacho faces - I will service the internal movement then. Pat

[gregimotis]

Glad to here it worked out for you.  I've got some other jobs pending at the moment, but may end up following your lead - thanks for the rundown.