750 commando rear wheel play and grease.

Good day,

So I had some play and grease in the rear wheel set up. I could tighten up the axle but than my speedo would be lucked up.

So tonight I removed the rear wheel and made some pictures. The bearing of the wheel and brake feel good and no excessive play is found. Could somebody light up any technical back up. Am I missing some parts?

Cheers
Nick

Is the play in the rear wheel/axle OR in the swingarm? I had slop in the rear but new swingarm bushings and a pair of swingarm locking clamps (or whatever they are called) solved the problem.

Hi,

No there’s no excessive play in the swing arm. If I torque the axle, the play is gone but the wheel is heavy to turn. I’ve read somewhere that maybe something in the bushing could be wrong or missing.

There is a spacer that fits into the speedo gearbox. I can't really tell from the photo if it is there or not. If it is, then you will need to take the hub apart and sort out what is missing or damaged. It is a bit of a challenge reading the manual and sorting out the parts but worth the effort as it certainly shouldn't stop the wheel from spinning freely when the axle is tightened.

The spacer is #34 in this diagram:
http://www.oldbritts.com/1972_g17.html

It is probably still in the speedo drive but check.

Here is a diagram of the pieces of the hub assembly:


The diagram comes from this thread:

https://www.accessnorton.com/NortonCommando/rear-axle-puzzle.5685/page-2

Re the speedo gear...be careful that it is correctly assembled/lubricated. Last week while we were on the IOM for the Manx GP in the parking lot at Sudby, a gentleman with a Commando had to pull his speedo gear. I'm not sure what the specific issue was but the whole speedo gear assembly became red hot while riding! Needless to say, it totally quit working.

nick's_Cafe said:

Hi,

No there’s no excessive play in the swing arm. If I torque the axle, the play is gone but the wheel is heavy to turn. I’ve read somewhere that maybe something in the bushing could be wrong or missing.

Click to expand...

The metal of the drive gearbox between the spacers can eventually crush causing the gearbox to rub on the hub cover plate. The answer is usually to fit a shim inside the drive gearbox to restore the lost clearance.

https://www.accessnorton.com/NortonCommando/speedo-gearbox-problem.2359/

https://www.accessnorton.com/NortonCommando/squashed-speedo-drive-2011.8031/

Ah the spacer, I’ve read it somewhere...


This is an example from the forum.
I can confirm it is in, could it be out of spec?

If the axle can fit easily through the speedo spacer, and the spacer is a snug fit in the speedo drive, the spacer is not out of spec.
Can you spin the drive dogs in the speedo drive by hand, with no tight spots or drag? The speedo drive itself is notoriously unreliable, the soft large ring gear inside being worn away until there is almost no engagement with the pinion, and subsequent lockup. I've now taken to buying used Smiths drives for different bikes (as long as the ratio is 15:12 (or same 1.25:1) just hoping to score a decent ring gear. Anyone with a good 15-tooth gear is welcome to contact me and make some money!

The speedo drive body can also spontaneously distort, begin rubbing on the shiny hub cover.

Assuming the speedo drive is good (and it's almost impossible to tell unless you drive out the rivets and take it all the way apart), more likely in your case is the "very thin washer" between the dummy axle and the brake drum as seen above. Or maybe you have a shot bearing?

Good luck, and please let us know what you find.

Another thing I've seen is the speedo drive is warped, slightly dished outward. When this happens it rubs the hub cover. Your speedo gear box should look like the one you pictured from a forum post.

B

Thanks for the comments.

I have some technical back up from NHW here in the Netherlands. So it will be sorted Checked the bearings today and they have signs of wear, so will replace them also. Will let you know what sort the rubbing etc.

Nick

Well NHW here in the NL changed the bearings top job! They were shot and probably gave a lot of play on the wheel that caused the rubbing of the speedo.

All sorted now!

Cheers an thx for the help.