NKII Rear Hub Squeak

marshg246 · Jul 30, 2022

L.A.B. said:
You've misunderstood me. My description of the housing bowing outward in the centre obviously results in the rest of the housing bowing inward whichever way you choose to look at it.

"obviously"? Nope!

L.A.B. · Jul 30, 2022

marshg246 said:
"obviously"? Nope!

Whichever way you choose to look at it as I said. Either the centre is bowed up (outward) or the outer rim is bowed down (inward) the face is no longer flat.

Cuppy · Jul 30, 2022

I'm still a little confused how the speedo drive can cause my rear wheel binding when axle is torqued to near spec. It butts against the spacer #31 on the bearing side and the top hat spacer #34 on the outside. If I back off the axle slightly it spins freely. Not sure how to resolve after reviewing threads with similar issue.

L.A.B. · Jul 30, 2022

Cuppy said:
I'm still a little confused how the speedo drive can cause my rear wheel binding when axle is torqued to near spec. It butts against the spacer #31 on the bearing side and the top hat spacer #34 on the outside.

But is it rubbing on the casing due to the distortion? Also, the case distortion can cause the ring gear to bind.

Shim on speedometer drive?

I have assembled the wheel, all new parts, bearings in the proper place. I am using one Dons 1 piece axle. When I fit the speedometer drive to the wheel, there is a chaffing that I can hear. Its not terrible but I dont think there should be ANY contact with the Hub-Cover. I can see some...

www.accessnorton.com

(Apparently, I'm not the only one to describe the centre as bowed or "bulged out").

Cuppy · Jul 30, 2022

L.A.B. said:
But is it rubbing on the casing due to the distortion? Also, the case distortion can cause the ring gear to bind.

Shim on speedometer drive?

I have assembled the wheel, all new parts, bearings in the proper place. I am using one Dons 1 piece axle. When I fit the speedometer drive to the wheel, there is a chaffing that I can hear. Its not terrible but I dont think there should be ANY contact with the Hub-Cover. I can see some...

www.accessnorton.com

(Apparently, I'm not the only one to describe the centre as bowed or "bulged out").

It must be as I can't even get a .0015 feeler gauge between the speedo gear and hub cover. Speedo gear is new and never been in service. How much gap is expected?

L.A.B. · Jul 30, 2022

Cuppy said:
Speedo gear is new and never been in service. How much gap is expected?

There's no specific gap measurement as far as I'm aware but the drive gearbox needs to be well clear of the hub cover.

Cuppy · Jul 30, 2022

Not sure what well clear is and I will measure to make sure gear is not bowed out. There is a felt retaining washer (#45) that was left out after a bearing (sealed) change but I don't see how that would have any affect or would it?

L.A.B. · Jul 30, 2022

Cuppy said:
Not sure what well clear is and I will measure to make sure gear is not bowed out.

I can't tell you exactly what "well clear" is in terms of a dimension but sufficiently far enough away that it doesn't rub and should be checked periodically in case the case does begin to bulge.
If it needs a shim on the inside to achieve that then I can only suggest you fit one as I eventually had to do to my Mk3's drive gearbox.

NickZ · Jul 30, 2022

Before I figured out a good technique for fitting everything between the wheel hub and the right side swing arm, I caused distortion to the speedo gearbox case by levering against it while trying to fit the spindle spacer (#4 in parts diagram). If you do something like that, you can have a brand new gearbox that contacts the hub cover.

Tornado · Jul 30, 2022

In the linked thread above Dyno Dave on last post of thread states the soft potmetal of the drive housing is being extruded when axle is torqued too much (like the spec'd 80 ft-lbs I bet), which causes the bowing and hub cover contact.

If running without the cover (as some do for the look), does this eliminate the problem or will drive contact hub itself?

marshg246 · Jul 30, 2022

Tornado said:
In the linked thread above Dyno Dave on last post of thread states the soft potmetal of the drive housing is being extruded when axle is torqued too much (like the spec'd 80 ft-lbs I bet), which causes the bowing and hub cover contact.

If running without the cover (as some do for the look), does this eliminate the problem or will drive contact hub itself?

The one I took apart yesterday ate completely through the cover and was lightly touching the hub itself. It was bowed more than others I've seen. It still was working OK but between bad bearings and that rubbing, it made a terrible noise when turning.

Cuppy · Jul 30, 2022

NickZ said:
Before I figured out a good technique for fitting everything between the wheel hub and the right side swing arm, I caused distortion to the speedo gearbox case by levering against it while trying to fit the spindle spacer (#4 in parts diagram). If you do something like that, you can have a brand new gearbox that contacts the hub cover.

I'm quite sure that didn't happen. I have a single axle coming Monday so I will measure the gearbox then.

Cuppy · Jul 30, 2022

Tornado said:
In the linked thread above Dyno Dave on last post of thread states the soft potmetal of the drive housing is being extruded when axle is torqued too much (like the spec'd 80 ft-lbs I bet), which causes the bowing and hub cover contact.

If running without the cover (as some do for the look), does this eliminate the problem or will drive contact hub itself?

Overtightening may have happened but no way I got close to 80 ft/lbs

Tornado · Jul 30, 2022

Perhaps someone with old drive casings laying around could try a torque squash test to see if any bowing occurs as DynoDave claims, and at what torque range. Then we'd have an answer we can all use.

Tornado · Jul 30, 2022

Ok got my drive squashed back to near flat on outer end. Prior, it measured .957" including top hat flange to inboard brass surface (took measure using depth guage on verniers through axle hole while housing sat on flat surface). After squash, down to .837". Gave the innards a good clean out as I found a few splinters of alu cover laying on the inner ring. Pryed the felt sandwich out and brushed it to remove any flecks that may have got in. New grease packed.
Fitting on wheel, torqued to 45 ft-lbs, gave easy visual clearance off hub cover. Took it to 50 ft-lbs and no visual change. Test riding I will check for heat at the drive, which seems like a good early indicator of issues.

Tornado · Jul 30, 2022

Btw, one slight nit pick on the one piece axle, the nut and bolt head are Metric, both 24mm. So it means we need to carry three wrench formats around if worried about roadside tire work etc. Guess cresent/adjustable wrenches are the best option there.

Cuppy · Jul 30, 2022

Tornado said:
Btw, one slight nit pick on the one piece axle, the nut and bolt head are Metric, both 24mm. So it means we need to carry three wrench formats around if worried about roadside tire work etc. Guess cresent/adjustable wrenches are the best option there.

I will need to rely on adjustables then.

Tornado · Jul 30, 2022

Cuppy said:
I will need to rely on adjustables then.

I found a light weight alu tire spoon in my tool box that has a 24mm hex ring on the handle end. Think I got it online from Fortnine here in Canada, but it might be a Motion Pro item.

Tornado · Aug 1, 2022

Ok just completed a 250 KM "test ride" in 28-31 Cel. At 50-60 MPH for around and hour, Speedo drive stayed a wee bit above ambient based on bare finger temp guage. Brake hub over pad contact area also slightly warmer than ambient (with no rear braking applied for past 30 min).

Only issue that came up, on way home, noted idle would drop suddenly at stop lights occasionally. Was not doing so past earlier today nor previous weeks of riding. Maybe related, the right side sometimes gives a pop on sudden throttle roll off, like when engine braking or shifting. Been doing that for some weeks, about once or twice in 20 minutes of urban riding.
I gave the right side carb a wee bit more throttle stop screw idle rpm adjustment for last ten minutes to home today. No more sudden idle dips. Will see if that solves it fully.

marshg246 · Aug 1, 2022

Tornado said:
Perhaps someone with old drive casings laying around could try a torque squash test to see if any bowing occurs as DynoDave claims, and at what torque range. Then we'd have an answer we can all use.

Partly tested:

1974 Trident, tightened to 80 ft-lb. No issue.
1970 Bonneville, tightened to 80 ft-lb. No issue
69S Commando upgraded to standard cush hub, took the rear wheel off today. Had to use a long breaker bar to get it loose. The speedo drive is bowed. I'll test more when I put it back together.

NKII Rear Hub Squeak

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