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1973 750 Tiger cafe/brat build:

After mounting a new rear tire and installing new brakes and shocks, I ran into a problem re-engaging the speedometer drive gearbox with the wheel hub while putting it all back together.

When I went to fit the speedometer drive gearbox (Triumph PN 60-3213), the inner distance piece (Triumph PN 37-3750) prevented the tabs on the gearbox drive from engaging the slots on the wheel hub. If I fit the gearbox without the distance piece, it settles on the hub and engages the slots as it should. Yet, when I put the distance piece in place, it holds the gearbox about 3/32" further off the hub, preventing the tabs and slots from engaging.

I have confirmed that both the gearbox and distance piece on the bike are the correct (and probably original) parts. What I don't know is whether the gearbox was properly seated when I originally removed the wheel. I had no way to check it because the speedometer was frozen and the cable is broken.

Looking closer, I found that there is no grease retainer between the bearing and the bearing retainer ring. Should there be? If so, that's why the gearbox won't fit properly. If there's not supposed to be a grease retainer, any other theories and/or solutions will be appreciated.

Thanks in advance...
Terry
 

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Hi Terry, I have '73 Tiger. There is no grease retainer on outside of bearing. You can plainly see the bearing balls etc.

The sleeve with the slots that screws into hub doesn't actually locate the bearing. The bearing is a supposed light press fit on the distance tube(spacer) 37-3753. So the right bearing is free to move left/right in hub itself.

The left bearing is held into left side of hub with the steel screw on retainer 37-4181. This bearing keeps wheel from moving sideways. The distance tube enters the left bearing. Then right bearing is pressed into hub with center of bearing sliding over end of tube until it hits the shoulder. So the right bearing is located by the 37-3753. It is held tight against the tube by your 37-3750, which is held by the speedo drive.

The spacer, speedo drive, the little spacer outside speedo drive fills the space. So when you tighten axle everything is pushed to the left against left bearing. The axle passes inside the distance tube.

So... My hunch is the right bearing has somehow moved to the right while working on bike, or pushing axle through.
I'd take a socket or something & see if you can drive bearing deeper to seat it on the tube. However, wipe the grease from bearing hole so you can make sure the distance tube is actually going inside the bearing & not offset of hole. Also look inside hole of left bearing as tube could have slipped out of that one as well.

The slotted speedo drive tube does not actually touch or hold in the right bearing. You should see a small gap between end of tube & bearing.

My long spacer(37-3750) under speedo drive is 1.342" long.

You can flush old grease out of speedo drive by holding normal grease gun end to nipple. Hold it very tight & pump gun. I've done this many times. If you over grease drive it will ooz grease out hub past felt seal until it finds it's amount. No harm done. Just wipe off with rag by spinning wheel. Lack of grease is killer of the drive.

If needed I can post some photos of my right bearing. All my parts are 100% correct from new.
Don
 

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Discussion Starter #3
Thank you, Don. I'll take a look. I've been working front to rear and everything on the bike has been correct up to the point of working on the rear axle. Upon removing the rear wheel, I found incorrect brake shoes, a washer missing, and a spacer in the wrong position. I guess that's to be expected on a bike this old and neglected.

Thanks again.

Terry
 

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Hi Terry,

no grease retainer between the bearing and the bearing retainer ring. Should there be?
As Don posted, no.

However, does that mean you put in the other Grease retainer (part #15)? If you did, do the new bearings you fitted have seals? If they do, that's the or another problem; as Don posted, original bearings didn't have seals, that's the reason for the Grease retainer; if you fit sealed bearings, the Grease retainer becomes an additional spacer ...

Also, did you compare the widths of the old and new bearings? Regrettably, different bearing widths are another gotcha visited on us by parts of the supply chain trying to make too much profit from the turnover ... :rolleyes:

Hth,

Regards,
 

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HI Terry, It's unlikely for the inner tube to be fully displaced with you speedo drive going in far as it does.
Anyway here's the photos I have of my rear hub. I wiped grease out for photo. Often the area has a fair amount of grease, but not full of grease by any means.
IMG_2972.JPG
IMG_2974.JPG

Don
 

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Discussion Starter #6 (Edited)
Thank you, Don and Stuart.

As an aside, I have not removed the bearings because they are new. The PO had renewed them right before he decided to sell the bike to me (That's another story).

Anyway, last night, while going over photos I took when I removed the rear wheel (back in September), I was reminded that the axle had been installed right-to-left instead of left-to-right. Of course, this meant that during disassembly, I had to drive the axle out in a left-to-right direction. I took a quick look last night and it appears that the right side bearing is slightly unseated, possibly from me having to drive the axle out in the "wrong" direction.

Next step is to attempt to seat the right-hand bearing properly and reinstall the wheel/axle assembly. If that doesn't work, I'll remove the bearings and start from scratch.

Busy weekend ahead, but I do plan to spend time on the bike at some point. I'll let you know what happens.

Thanks again.
 

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Discussion Starter #7
Well, I finally got back to the bike this afternoon and found that the right side bearing was indeed pushed out of the hub a little over 1/16". I re-seated it with a mallet and socket and the speedometer drive seated on the hub as it should.

Thanks again to Don and Stuart for your detailed replies. This issue had become much too fiddly and drawn out and the information you provided put me on track.

Onward through the fog...

Terry
 
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