Black Star of Death

Status
Not open for further replies.
Tornado

Tornado

VIP MEMBER
Country flag
Speedo drive spewing BSoD on hub...this just first ride after adjusting rear wheel alignment and chain play. Searching for threads but only quite old ones found. What options do I have for repair? Just replacement or???

Cheers.
 
Yes, old threads, but plenty of good information in them. It's all there. Need to check the spacers and if the drive is bent.
 
For my response I'll make the assumption that grease is escaping from around the speedometer drive.

If the speedometer is working normally (a lot of bandwidth here) then the drive was over greased or the felt seal has seen better days or both; probably more of a good thing as the Smith's drives are very hard to find in the NOS category, but the felt seal is still available.

Issues like yours are far from un-common in the Summer heat.

The drives like to be cleaned and re-greased (hand packed) periodically, it is when they are neglected and not grease that the two gears feed on themselves.

I do not recommend the use of compressed air driven grease guns on any grease point of the Norton, especially the speedometer drive.
 
I did grease it with a high performance Synthetic grease from a push type mini gun when I built the rear wheel 4-5 months ago. As far as I know, this speedo drive is original and bike had only 8300 miles on the clock when I got it 7 months ago...speedo benched today at 9070 miles...and seems like I might have warped it when torquing axle to recommended 70 ftlbs.

I will pull it off and see if a new felt will suffice.

J.S.: yes, the (now) black grease escapes from under the drive unit and spreads out across the hub cover in an amazingly beautiful star pattern. Wish I had snapped a shot before smearing it off with a paper towel on my way home today. Would have made a more interesting thread ;-)
 
Last edited:
OK, had speedo drive off bike, noted the hub side brass casing had some deformation, two depressions from flat at 180 degrees apart. Popped the casing out, cleaned it all out of nasty smelling black filth. First thought no felt present, but then found it sandwiched in the casing with metal washer holding it in place. Pulled that apart and felt looks very nice condition...not frayed or mangled...even cleaned to nearly white using WD40.
Globbed new bearing grease into the ring periphery and worm gear as much as would go. Pumped some more in from zerk fitting. Flattened the deformations in casing using an old brake piston to tamp it down on a flat steel surface. Went back in nicely with light taps.

Got it back on hub, cable connected, chain tension set, wheel aligned, axles torqued, good to go...then found the !@#$%÷$¡¿Ing felt washer ring still sitting on my workbench :-(
 
I have a modified gearbox drive that I reversed the output on and relocated to be driven from my front wheel opposite from the disc brake side. I changed the zerk fitting from that pyramid shaped one to an american shaped nipple so I can use my grease gun to pump oil into the housing. I also bought a cartridge of Jewel amber oil which I'm told is a better lubricant for meshing gears than grease... My $.02
 
Hey Tora .... just read your last post .... sorry but I laughed out loud .... I’d bet we all at one point or other have been in same situation .... good on you for sharing and not putting your fist through closest wall....
Craig
 
Actually I view all mechanical work as character building exercise ... the ride is the therapy .....
 
One of the best things I have done to my commando is re locate the Speedo drive onto the front wheel.
The cable is very straight to the Speedo head and there is no wavering or flickering
The Speedo is set with a GPS and is absolutely spot on which is what I need in my neck of the woods
 
I went to the Jewel Amber on some of my speedo drives and the swinging arm on the 74 850 unsealed type.
No idea if it lubes better but it still migrates out to give the Black Star effect. When it stops it likely means
it has all pissed out. Still drips out of the swinging arm but not as fast.
Guess a small win or at least not a big loss.
 
Wish I had snapped a shot before smearing it off with a paper towel on my way home today. Would have made a more interesting thread ;-)
Click to expand...

Here's a pic of the Black Star:


Black Star of Death
 
Last edited:
baz said:
One of the best things I have done to my commando is re locate the Speedo drive onto the front wheel.
The cable is very straight to the Speedo head and there is no wavering or flickering
The Speedo is set with a GPS and is absolutely spot on which is what I need in my neck of the woods
Click to expand...

Me loves my Smith's electronic speedo and tach - eliminates both ugly cables.
AND.... no more regular maintenance, replacement of worn speedo drives, or spastic indicators.
 
Anglophile said:
Here's a pic of the Black Star:


Black Star of Death
Click to expand...
From what I could tell, it seemed to me the starring can only happen as the grease heats up/melts then
escapes the drive "seal" and spreads a limited amount via centrifugal forces until it "freezes" on the hub cover. Was quite semisolid and difficult to wipe off with just a paper towel.
Was fully contained on my bike for about 700 miles (only had the bike 7 months) and failed the day I slightly upped the axle nut torque to 80 ftlbs to eliminate some chain slackening I'd noted. So I guess that was enough to crush the drive unit a little, putting it in contact with hub cover, making too much heat...
 
Last edited:
Yup , Lately more than usual ... trying to use up the 5 imp. gallons of 114oct race gas I got in spring .... that why I have kept it all these years right ... to ride on nice Sunday mornings.......
 
Had the bike out for good high speed run today, first ride since speedo drive work...got the Death Star again...but was kinda expecting it as I was not careful about where excess grease was going in the drive...much mess present on wrong side of felt, towards center of drive...and there's nothing there to prevent flow out when at speed plus frictional heating.
Wiped down at fuel up and will see if excesss is basically done.
 
Status
Not open for further replies.
Back
Top