Layshaft bearing at RGM

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worntorn

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I pulled the 920 gearbox apart today to check the condition and to replace the Layshaft bearing if needed.
It still has the 6203 ball with brass cage, so I ordered the replacement roller bearing from RGM

This information on the RGM site doesnt seem to jive with other experiences, including my own. My MK3 had a Portugese ball bearing and it was falling apart when I changed it to the roller.

Place your mouse over this image
LAYSHAFT SUPERBLEND BEARING
LAYSHAFT SUPERBLEND BEARING


LAYSHAFT SUPERBLEND BEARING​

PART NO​

067710​

RGM Approved

HEAVY DUTY LAYSHAFT SUPERBLEND BEARING

40MM X 17MM X 12MM QUALITY ROLLWAY BEARING THAT FITS ALL ROAD NORTON'S ON THE INNER LAYSHAFT POSITION REPLACING THE EARLIER BALL RACE. USED BY NORTON'S FROM APPROXIMATELY 1973 ONWARDS AS THE EXTRA TORQUE OF THE 850CC ENGINE COULD MAKE SHORT WORK OF THE BALL BEARING USED PREVIOUSLY.

SEE 065542 FOR THE
 
worntorn said:
"USED BY NORTON'S FROM APPROXIMATELY 1973 ONWARDS AS THE EXTRA TORQUE OF THE 850CC ENGINE COULD MAKE SHORT WORK OF THE BALL BEARING USED PREVIOUSLY."
Click to expand...
Yes, what RGM says there is incorrect as the roller bearing was never used although the roller bearing part number is listed in the 850 Mk3 parts book.

RGM: "SEE 065542 FOR THE EARLIER BALL RACE."
"065542" is the later (850 Mk3) sealed 6203 2RS front RH and rear LH wheel bearing.

The original open (layshaft and wheel) ball bearing was 6203 and Norton part 040100.
 
At risk of not answering your question, I'd suggest the 6203TB is a better bearing for the job.
The Superblend is certainly strong enough, but you lose the positive location feature of the original bearing, and shimming up against surfaces which weren't designed for it is not ideal.
I believe that whip in the gearbox shafts causes the failure in the original bearing, and the TB is designed to accommodate this.
 
worntorn said:
I pulled the 920 gearbox apart today to check the condition and to replace the Layshaft bearing if needed.
It still has the 6203 ball with brass cage, so I ordered the replacement roller bearing from RGM

This information on the RGM site doesnt seem to jive with other experiences, including my own. My MK3 had a Portugese ball bearing and it was falling apart when I changed it to the roller.

Place your mouse over this image
LAYSHAFT SUPERBLEND BEARING
LAYSHAFT SUPERBLEND BEARING


LAYSHAFT SUPERBLEND BEARING​

PART NO​

067710​

RGM Approved

HEAVY DUTY LAYSHAFT SUPERBLEND BEARING

40MM X 17MM X 12MM QUALITY ROLLWAY BEARING THAT FITS ALL ROAD NORTON'S ON THE INNER LAYSHAFT POSITION REPLACING THE EARLIER BALL RACE. USED BY NORTON'S FROM APPROXIMATELY 1973 ONWARDS AS THE EXTRA TORQUE OF THE 850CC ENGINE COULD MAKE SHORT WORK OF THE BALL BEARING USED PREVIOUSLY.

SEE 065542 FOR THE
Click to expand...
Glen,
If 4th gear layshaft was installed backwards,would the trans go into all gears but would bind up when inner cover put into place? I have had this brand new (rebuilt) unit apart without taking the layshaft out at least 5 times and cannot find the answer.Everything goes in properly,quadrant timed correctly,goes into all gears but then binds after inner cover goes on.
This rebuild was done by a reputable dealer and everything else seems nicely done.Any thoughts would be appreciated
Thanks,
Mike
 
Hi Mike

From the look of the drawing, it wouldn't be possible to install the Layshaft wrong way round and still get all of the gears into the box.
Something else must be off a bit.
Is it possible that the Layshaft bearing is not all the way into its seat? Is there a bit of endplay on the Layshaft when the inner case is tightened up?
There should be about ten thou of endplay, if a Layshaft roller bearing has been fitted.

Glen
 
worntorn said:
From the look of the drawing, it wouldn't be possible to install the Layshaft wrong way round and still get all of the gears into the box.
Click to expand...

However, it is possible to install the layshaft with the 4th gear pinion backwards (and that was the question).

The gear could then rub on the case so the face with the raised centre goes against the bearing inner race (Factory Manual D9,12).

andover-norton.co.uk

Motorcycle parts and spares for Norton motorbikes - Genuine Andover Norton Spare Parts - Andover Norton Motorcycles Parts - Original Andover Norton Parts

Motorcycle parts and spares for Andover Norton motorbikes: Andover Norton manufactures and supplies all Genuine Factory Spare Parts for Norton motorcycles built before 2002.
andover-norton.co.uk

Layshaft bearing at RGM
 
worntorn said:
I got that question wrong way round, sorry.
That's why Les earns the big money :)

Glen
Click to expand...
Les has a lot of Norton knowledge, why he's on he big money, no its good to know someone has all the answers to anything Norton, good one Les :)
 
Thanks, but I certainly don't have anywhere near all the answers. ;)
 
I went ahead and removed the layshaft and all gears were in properly with the shoulder on layshaft 4th facing the bearing. I still have no idea what is causing my problem.Should the layshaft bearing be flush with the main case?Everything goes together nicely until I put the inner cover in place.No evidence of anything rubbing anywhere. I am at wits end on this.Any guidance would be appreciated
Thanks,
Mike
 
YING said:
Should the layshaft bearing be flush with the main case?
Click to expand...

The bearing outer race should be up against the shoulder in the case that puts it approximately flush.
A couple of examples:
www.accessnorton.com

Layshaft Roller Bearing Flush w/Case?

Rebuilding the gearbox on my 1974 Commando and I have replaced the old Portuguese ball bearing with a new FAG roller. It felt like it was fully seated in the inner case, but I see now that it is slightly proud of the case. Should this bearing be seated so that the outer race is flush with the...
www.accessnorton.com www.accessnorton.com
www.accessnorton.com

Layshaft Bearing ID

Hey all, I popped my gearbox open to replace my shaft and decided I should check on the layshaft bearing. Does anyone recognize the bearing as the original one or if it is safe to run? Thanks! Dan
www.accessnorton.com www.accessnorton.com
...but without the punch marks!
 
YING said:
I went ahead and removed the layshaft and all gears were in properly with the shoulder on layshaft 4th facing the bearing. I still have no idea what is causing my problem.Should the layshaft bearing be flush with the main case?Everything goes together nicely until I put the inner cover in place.No evidence of anything rubbing anywhere. I am at wits end on this.Any guidance would be appreciated
Thanks,
Mike
Click to expand...
Is your mainshaft first gear flush with the spline of the shaft ? are your gears new and/or was it working before ?? it happens to me once that two new gears were a few thou thicker than the previous one !!and thus everything ok with inner cover on till you tighten it to the main case (either with the five small nuts and /or the mainshaft nut ..........
 
I had a similar problem, eventually realised the layshaft wasn’t finished off correctly. There was a small raised shoulder that the 3rd gear bush was binding on when the case was tightened. Sorry no pics.
 
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