Norton Bike Gear Box Casing Repair.

[@josephleister9198]

Very nice work, thank you for sharing...

[@unclebobsbees4899]

Great work Nigel. At least another decade of service with a minor investment of time.

[@EmptyPocketProductions]

Love the music.... I nearly had a shit when you said .004" into an alu housing. Glad you decided to go with .002 instead. Gotta love when you heat bearings and or the housing and the slip fit is perfect. Nice work.

[@Rustinox]

I like your fixture plate setup. It's a good idea.

[@MattysWorkshop]

Gday Nigel, it’s amazing how much heat will expand material, very interesting setup which work perfectly, the glue you used to hold the small spacers on with is turning out to be very handy, throughly enjoyed once again, beautiful job mate, Cheers Matty

[@GoCreatehms]

Thanks Matty. it only needed an increase in temperature of about 80 degC to expand the bore 66mm bore about 0.1mm. Cheers!

[@paulrayner4514]

your a better man than me, I wouldn't even attempt that. well done

[@pgs8597]

G’day Nigel. The fixture plate worked out well, got to love the sound of the bearings slide into place after heating the housing, ah, a sigh of relief. Cheers Peter

[@leonadeau2849]

Very nice excellent work

[@MrFactotum]

nicely recovered GCHMS, a change is as good as a rest from loco, them hot plates come in handy, i've put one on my wanted list. stay safe, catch you next time. regards mr f

[@TheKnacklersWorkshop]

Hello Nigel, I watched Robin R's mammoth spindle rebuild video last night... he did same with a hotplate so no bashing/pressing of the bearing were needed, clearly great minds think alike. I may get one of those hotplates for my workshop but will my skill level I think it will most likely be used for soup at lunchtime. Take care. Paul,,

[@GoCreatehms]

Hi Paul Yeah, the hot plate will heat soup and boil a kettle as well :) I'll search out Robin's spindle rebuild video, sounds interesting., Cheers!

[@oh8wingman]

I owed three Nortons back in the 70's and one of the known things about them was the failure of this bearing. This fellow was lucky. Most of the time it blew the back out of the transmission case when it seized and broke the mainshaft in half making it so much junk. For those who were fortunate enough to catch it before it failed completely, this was the way to fix the problem.

[@GoCreatehms]

Thanks for that insight into Noton Bearing Failures, I was quite amazed when my friend told me that the out race of the bearing had cracked in two halves, hard to imagine how that's possible. Anyway, good to know I made the repair in the same way as others before me. Cheers!

[@oh8wingman]

@@GoCreatehms You may want to tell your friend to watch out for something which is rather strange but true. Frequently when this bearing starts to fail, when starting out from a standstill, your kick start arm will go back and when you pull the clutch to shift the spring will whip ahead and smack you in the back of the calf muscle in your leg. No one knew why this would happen because the kickstart assembly had nothing to do with the bearing, but this was a sign. It will do this for a day or two and then stop leaving you to think whatever was ailing it has "self repaired" itself. Trust me, it hasn't. What has actually happened is the bearing is now in full failure mode and it's only a matter of time before it seizes altogether. Don't ask how I know this........

[@GoCreatehms]

Thanks for that info, This bearing must have quite a load on it. I'll certainly pass on the message. Cheers!

[@CraigLYoung]

Thanks for sharing!

[@peterrestaino7047]

amazing my Norton has loose fitting bearings same predicament

[@GoCreatehms]

I met a guy recently that told me he's done many of these types of repairs on Norton gear boxes, he used his mill with a boring head rather than a lathe. Thanks for taking the time to view and comment, much appreciated.

[@peterrestaino7047]

@@GoCreatehms your welcome but mine would need both done, its a shame because the case is good otherwise

[@tomrussell7185]

Well done on that repair.

[@bobuk5722]

Hi Folks. The important thing with this repair is to get the new bearing location concentric with the old one. The two halves of the gearbox casing are dowelled which means the shaft alignment is critical. The bearing housings might have been line bored at manufacture, more likely the dowel holes were used in a jig and the casing halves machined separately. Makes for easier inventory control. It's tricky to get this job right and an impressive repair. The cake icing would be to know that the final assembly ran smoothly! BobUK.

[@GoCreatehms]

Hi Robert Time will tell whether it's worked out OK, it will be w while before it's re-assembled. The new bearing was a loose fit in the bearing housing presumably because of the damage done by the broken bearing, so I couldn't really use the old bearing location as a ref. It can only be assumed that the smaller bore was machined concentric with the bearing location, but that was slightly out of round. So it's fingers crossed. Cheers!

[@stupollock6851]

Perhaps original bearing broke because not in centre location meaning your fix might be the solution.

[@crozwayne]

the gearbox halves were not line bored. AMC and Norton made the gear box shell on a Herbert capstan using a special two position chuck/fixture with the two positions of the sleeve gear and layshaft concentric with the sliding chuck

[@Fubar12341]

Nicely Done , Much better than loctite

[@paulskelton6836]

Nicely done. Cheers.

[@KrashPad]

The Norton gearbox case is known for cracking between the bearing bores. Removing material from that area almost guarantees the repaired case will crack.

[@GoCreatehms]

Thanks for your interest and comment. Yes, I was concerned about weakening the casting which didn't seem to have a lot of strength between the bearings. It was what my friend wanted and apparently a common repair though maybe not a successful repair regarding longevity.

[@derekblake9385]

Great job

[@steamboy25]

Hi Nigel ,I wish i had a £1 for every one of time I have done this job when I was doing sidecar motorcross with a Weslake motor and a Norton box.Why did you just not do it on the mill with a boring head,much easier. take care Ken R

[@GoCreatehms]

Hi Ken, yeah a boring head in the mill would have been a good option if I'd had a suitable boring head, though I'm more confident doing jobs like this on the lathe.so a good boring head probably wouldn't have changed my method. Anyway, hope to see you at a steam rally in the not too distant future, wishful thinking maybe, but we live in hope. Cheers!

[@johnutting9615]

Does this gearbox still use the RLS 9Z bearing or is it metric ?

[@GoCreatehms]

Sorry, I don't know. I did this job for a freind of a freind, I don't know anything much about the bike/engine. Anyway, thanks for your interest in the video.

[@aceroadholder2185]

An alternative to pressing the bearing and sleeve in would be to make them slip fits then install them with Loktite bearing retaining compound. This would avoid stressing the thin casting. To get the best result consult the Loktite application instructions. I've seen a Norton twin engine cam shaft cut in two with a wire EDM and the two pieces reassembled with a ground pin in the hollow cam. This was done to index the cam lobes to use in an engine with staggered crank pins. Loktite technical assistance specified the clearances and compound to give the required strength of the joint. That engine has been in service for 25 years. Cheers from NC/USA

[@GoCreatehms]

Thanks for that information, very much appreciated, amazing stuff Loctite especially when done correctly. cheers!