Speedo Gear Rubbing on Hub

I don't think there should be any need for rivets. 34 is not turning, 29 is not turning, a washer between 34 and 29 will not turn, 34, 29 and the washer will all be pressed together when you tighten the spindle. The only thing that is turning is the wheel, the bearing nut with the dogs engaged to the spedo box which makes the spedo gearbox work.

Actually, the additional washer will go between the gearbox inside housing and the hub spacer (29) so the washer will need to be on the large side of 0.675 id, and somewhat less than 1" od because it will have to fit between the tophat spacer od and the recess in the gearbox.

Edit:
Wait, wait, the extra spacer needs to go between 34 and 29, not next to the gearbox housing, so it can be a very narrow washer that just fits over the spindle.



Dave
69S

Thanks Dave. Danged good service.

Now put that thing together and ride it!

Edit: "If you can." You guys seems to be having a "New England winter" this year, while we've not had it so bad. Thanks for stopping all that snow before it found its way up here! Hope you're making out okay and on the roads again soon!

Man, we have had a time. Got 23" first hit, only 6" second one, but to the east like DC got lots more. However, my drive is a 1/2 mile gravel hill and the freeze/thaw every day makes it a mud pie. Only way I can get up is 4WD. Until the ground thaws out the drive will be impossible. At least I can park at the barn which does not have the hill, but it is a walk to the house.

Dave
69S

Sounds very New England, except for the "thaw" part, which is clearly NOT a mercy - got to make it worse.

The Mrs. and I been starting to think about retiring down southish a bit (NC? SC?), and I must say this winter has us wondering!

DogT said:

I don't think there should be any need for rivets. 34 is not turning, 29 is not turning, a washer between 34 and 29 will not turn, 34, 29 and the washer will all be pressed together when you tighten the spindle. The only thing that is turning is the wheel, the bearing nut with the dogs engaged to the spedo box which makes the spedo gearbox work.

Dave
69S

Click to expand...

I see from your pix that you don't have the riveted retaining plate installed either. Is this an old part, or do you run this way? Are you suggesting just leaving it off entirely? I guess once the dogs engage, it will hold in place. I just wonder if the grease will!

Bonwit,

The riveted retaining plate, I think you are talking about the piece in the gearbox? The first picture shows item 34 placed on the spindle without the gearbox and slightly slipped into 31. 34 is a press fit into the gearbox and the riveted plate is part of the gearbox, so I have just taken 34 out of the gearbox. You can see the rivets in the second picture outside the space where I have drawn the arrow. I just happen to have everything apart at the moment.

After thinking about it overnight and looking at the parts again, I think we are pretty close to having this solved. I was wrong to say 34 contacts 29, it actually contacts 31, the bearing spacer through the gearbox. Item 34 is a press fit into the gearbox, item 5. The smaller diameter of 34 will slide into the bearing spacer 31. The lip of 34 bears against the outside of the gearbox (5) like a washer and the inside of the gearbox must press against the outside face of the bearing spacer (31) when all is tighterned (the bearing spacer 31 extends past the bearing locknut (27) by about 1/4" at least on mine). We are hoping that the race with the 2 dogs in the gearbox does not press too tightly against the bearing locknut (27) so as to compress things and make things tight. Looks to me that if the outer left side face of the gearbox (where the ratio is marked) rubs on the hub cover, there needs to be more space between the inside of the gearbox face (where I have the red arrow pointing to) and the bearing spacer 31. The only way to achieve that is to get a longer bearing spacer 31 or put a washer between the right side face of bearing spacer 31 and the inside of the gearbox to achieve enough clearance from the gearbox to the hub cover. That will require a washer that will fit inside the gearbox inner face where I have the red arrow pointing to, which would be a washer id .7", od less than 1", thickness determined by not rubbing on the hub cover. I don't know how this affects the space between the swingarm spindle holes, since my swingarm is out for coating at the moment.

I don't know why over time the gearbox start rubbing on the hub cover, something must be compressing after installing the rear wheel several times. Perhaps it is the gearbox part between 34 and 29 that gets compressed, everything else seems OK.

My oil furnace has decided not to work last night, so I need to either get a lot of firewood or get the furnace repair out here tomorrow, it always happens in the worst weather.

Dave
69S

DogT, I feel your pain. My LP fernace went out cost 1895.00. Could have got alot NORTON parts with that cash like sprag 199.00 oh well lifes a b@#%h then you die Phil

Okay, I think I broke the code. The problem has nothing to do with spacers, missing spacers, or crushed washer. It is simply an outward distortion of the speedo gear body. Now how this occured is still not clear, as top hat #34 is supposed to take the stress and prevent this from happening. Since my gear is suspect anyway, I tried bending the body back into shape using a socket and hammer. It worked perfectly. Still, I think my gear is history. I'm hesitant to reinstall it and risk a seizure and having the speedo cable become wrapped around the axle! That would really make my day.

Bonwit,

That sounds like the best reason that anyone could think of. I do notice about 1/16" of space between the felt washer, the dog gear and the gearbox. It could no doubt take a bit of compression before things start to bind up and that may get the gearbox away from the hub cover. I'll try it when I get my swing arm back. I do notice a bit of rubbing on the outside of the gearbox next to the tophat 34 spacer, I wonder what that is about?



Dave
69S

It's heresy but I gotta say it - It's a dumb design - making the thin walls of that high hat bushing, #34, carry the compression load of the tightened axle.

When I recieve my new washer, I shall remake one from 17-4ph.
I just made a new washer for behind the outside wheel spindle bolt, hardness checked it with the old one. The new one was 36.2HRC, & believe it or not, the original one was 2.2HRC.

While its off the bike I suguest that you safety wire the little tit on the rear end of the drive to the drive. A small hole drilled thru the solid part, then wired back to the grease nipple will keep it from being lost.

Bruce MacGregor said:

While its off the bike I suguest that you safety wire the little tit on the rear end of the drive to the drive. A small hole drilled thru the solid part, then wired back to the grease nipple will keep it from being lost.

Click to expand...

Good point. I'd add that it needs to be wired in so it can't come out at all. The internals get spit out too.

Yeah, I ended up buying a new one from Phil Radford. A month later, my speedo is bouncing all around. Anyone suggest a Smiths repair station that doesn't cost a fortune?

There was a recent thread about Smith's repair, see if I can dig it up. Did you check your cable, that will make the clocks jump around too if they are binding. Make sure when you have the cables mounted on the drive end, that the clock end if you pull the part that threads onto the clock all the way up, it should be flush with the cable end. If it sticks out, you risk damaging the clock, if it's below, it won't engage correctly.

Dave
69S

Well, just recieved my PATTERN speedo drive. First of all it is a horrible colour, couldn't get the felt seat over the drive on the wheel, then the seal & cover came off. Worst of all the inner won't rotate without jamming up against the gears.
Oh, & I will have to file out the hole to fit the top hat washer in it.
What a load of rubbish! I think I will make up a spacing washer for mine, though it is a bit too thin, & keep trying Ebay until I can find a decent one.

DogT said:

There was a recent thread about Smith's repair, see if I can dig it up. Did you check your cable, that will make the clocks jump around too if they are binding. Make sure when you have the cables mounted on the drive end, that the clock end if you pull the part that threads onto the clock all the way up, it should be flush with the cable end. If it sticks out, you risk damaging the clock, if it's below, it won't engage correctly.

Dave
69S

Click to expand...

Hmmm. I hadn't thought it could be a cable. I'll check that out. I assume the best way to do that is checking the item you're talking about and then looking for some sharp bend. I suppose I could hook up a drill motor to spin it.

Thanks for the tip!

Bonwit, Spin in reverse. Phil