Counter shaft threads knackered

[DRZ4Hunned]

I recently bought a FZS600, was hoping that it wouldn't have a welded sprocket, it didn't but I have now found out that the threads have been stripped on the shaft, and the new nut will tighten a small amount, then become loose again.

https://i.imgur.com/HjwmgY3.jpg

I'm leaning towards installing a new set of chain and sprockets and getting the nut welded to the shaft by a garage, unless the threads can be re-threaded?

I'm not going to replace the shaft as it seems pointless if I can just grind the weld off and re-weld when the need arises?

Would a few tac welds suffice just to hold the nut on?
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DRZ400-SM
FZS600

[Pete.]

Simple answer: yes. Tack-welding the nut to the shaft would cause it to act as a sprocket retainer. It's an almighty bodge but not as much as if you tried to weld to the sprocket directly.

Apart from that, those threads don't look so bad. I would bet that the most of the damage is in the nut threads, and a new nut would work on those shaft threads without resorting to weld-bodgery.
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a.k.a 'Geri'

132.9mph off and walked away. Gear is good, gear is good, gear is very very good

[DRZ4Hunned]

Cheers Pete,

I have actually tried a new nut and it does the same thing? I'd read that the nuts were made of a softer material than the shaft, so it strips the threads in the nut, rather than the shaft.

I'll go to my local garage tomorrow and see if they can help weld it.
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DRZ400-SM
FZS600

[Paulf]

I agree it worth trying a new nut, I have seen worse and still hold the full torque. But it your life on the line and if you are not confident it will hold you can always tack the nut for extra peace of mind.
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Past bikes simsom mofa 1s, suzuki hustler 250 (£35 in 1973), suzuki ts125k, mz150, yamaha yb 100, honda pc50, honda vision 50, all 2 stroke - then cars - honda pcx 125 (sold) own honda fes 125 and Mrs 125 spares or repairs. Started 1972 all accidents walked away no insurAnce claims

[ThatDippyTwat]

If you want to try using a nut to re-thread the shaft (better with a tap, but now always available/affordable), then use a stainless one, it will usually clean out any galling on the threads.
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'98 VFR800 (touring) - '12 VFR800 Crosrunner (Commuting) - '01 KDX220 (Big Green Antisocial Machine)

[Raffles]

[Pete.]

[P.addy]

These bikes have a habit of doing so.

Replace with the upgraded one, a quick google says its bigger, 12mm rather than 9mm. Assuming width there.

[DRZ4Hunned]

[skatefreak]

Wouldn't throwing the nut on and drilling through the nut/shaft/nut, placing a spline through be a more convenient method allowing far easier ease of access in future (especially if you don't have a welder/angle grinder etc at home?).

[DRZ4Hunned]

I've just found this, interesting idea:

https://foc-u.co.uk/index.php?action=downloads;sa=downfile&id=43

How would this compare to drilling through the nut/shaft/nut and putting split pin through?

No idea how hard it would be to drill through these hardened shafts with HSS drill bits.
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DRZ400-SM
FZS600

[DRZ4Hunned]

So I've got this far... 15mm Circlip on like what was done in that PDF. Does the circlip look seated correctly here?

https://i.imgur.com/GCeYmly.jpg

Also, tried drilling the shaft with a Bosch HSS drill, wouldn't even touch it. Do I need to get something like a cobalt bit?
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DRZ400-SM
FZS600

[redeem ouzzer]

You won't drill the shaft, they are extremely hard.
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Be a REAL MAN!

[DRZ4Hunned]

[zark]

IIRC the chap on foc-u enlarged the hole down the centre of the shaft - tapped a thread and then bolted a large washer to the end to prevent the sprocket nut moving off the end? Earlier fazers had a sprung plate on the inside of the casing that did pretty much the same. However - i would rather the nut didn't move along the shaft at all, rather than factoring in an 'acceptable amount' of free play??

So either re-furb/re-cut the threads and cross yer fingers - or tack a nut on... Seems more likely to succeed than trying to drill a hole horizontally through a (slightly moving) hardened shaft to fit an 'R' pin or something through it?

But looking at your picture again... my nut is just about flush with the end of the shaft - you sure you haven't still got the thinner (old) nut type?
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CBT - Oct 13. Theory - July 14. Mod 1 & 2 - June 15.
Rides a Fazer like an idiot... Edit: Now ride a Fazer Thou...

[DRZ4Hunned]

[zark]

[DRZ4Hunned]

[zark]

Now you've started the groove, slide the sprocket off so you're just working on the spinning shaft? But yeah, not much to play with...

How much sideways force will there be typically anyway?
____________________
CBT - Oct 13. Theory - July 14. Mod 1 & 2 - June 15.
Rides a Fazer like an idiot... Edit: Now ride a Fazer Thou...

[Pete.]

If you can cut a grove in the shaft with a hacksaw you can drill a hole in it with a decent drill.
____________________
a.k.a 'Geri'

132.9mph off and walked away. Gear is good, gear is good, gear is very very good

[DRZ4Hunned]

[DRZ4Hunned]

No luck with the cobalt bit either

Anything else to suggest?

How likely am I to potato myself with only using the circlip?
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DRZ400-SM
FZS600

[kramdra]

Carbide drills will go through it like my dick up your mum.

A puny M6 bolt can not replace an M18 nut, the slightest force and it will shear off. Circlip will break or wear into shaft and fall off.

One option, with it running, grind down the thread and get a new threaded spacer turned as a press fit, with a lump of weld. This is possible as the splines are a larger od. Better than new.

Another option you can make a retaining plates. Bin the nut. Drill a 2mm stainless plates to 17mm to fit the shaft. File out the hole to have a flat. Using a 2mm grinder cut a slot 8mm deep on the shaft, where the threads start. The plate should slide on the shaft and fit into the slot. Now drill a hole through plate and into the sprocket. Tap the sprocket hole M8. For redundancy use two plates, 2mm gap between opposing slots.

[Beehive Bedlam]

[DRZ4Hunned]