Apparently everybody got memo except me - Fuji axle nuts s#ck big

[Pursuvant]

On 9/25/2020 at 1:12 AM, clinical said:

Do you think there would be room to lock it with Safety wire instead of a pin?

Yes. You can if you use needle nose pliers, but it's a small space. 

I believe the 2016 svg650 nut had another problem preventing this approach - the height of the nut was too great (it's a castle nut). The axle is too short for that particular nut (the axle stopped short/too close relative to where you would have to drill axle - the "castle" cotter key or safety wire location, from my poor memory). That castle nut was just wrong for this axle as I remember test fitment from this perspective.

This Belmetric nut is no longer recommended - it too has seized under work stress

FYI note, my fuji nut failed at the speed shop where I was getting new rubber put on. After the fuji nut seized, they got the axle out by going to starboard side and drilling the head of the axle off.

Edited December 19, 2020 by Pursuvant

[longrider1951]

Bottom Line:

In case there is one other person out there who did not get the memo like me, this post is for you. Hope it helps save some aggravation and $$. For everybody else who got the memo, sorry I had to raise this known sore spot again.

 

 I ordered 3 of these nuts last night, I was going to adjust my chain but I'll wait until I have the Nylocks.  BTW notified today that they already shipped.

[clinical]

Quote

That castle nut was just wrong for this axle as I remember test fitment from this perspective.

Great thanks for the detail here.  I don't specifically need to safety wire, it was just a thought of how to potentially make the castle nut work.

Edited September 28, 2020 by clinical

[firstyammerha]

I need to put my bike in the shop for its 4000 mile service and I think I'll mention this situation when I do. I bet the chain was adjusted at the 600 mile service so I'm not going to try and loosen this nut again but let the shop people do it and probably replace the axle and nut with the R6 components. They couldn't be that expensive.

[mjh937]

1 hour ago, firstyammerha said:

I need to put my bike in the shop for its 4000 mile service and I think I'll mention this situation when I do. I bet the chain was adjusted at the 600 mile service so I'm not going to try and loosen this nut again but let the shop people do it and probably replace the axle and nut with the R6 components. They couldn't be that expensive.

Will the R6 axle fit our bike or will you be modifying parts?

[clinical]

On 9/29/2020 at 12:46 PM, firstyammerha said:

I need to put my bike in the shop for its 4000 mile service and I think I'll mention this situation when I do. I bet the chain was adjusted at the 600 mile service so I'm not going to try and loosen this nut again but let the shop people do it and probably replace the axle and nut with the R6 components. They couldn't be that expensive.

Not a bad idea to spray some WD-40 or penetrating oil on it before riding to shop.

[seven]

Thoughts on something like this?

LighTech D004 Rear Axle/Swingarm Pivot Nut

---

LighTech D004 Rear Axle/Swingarm Pivot Nut Manufactured in Italy from Hi-grade Aluminium, LighTech Special nuts are individually engineered to ensure quality and fit.CNC Machined from Billet...

Is aluminum a bad choice for tis application?

[blackout]

2 hours ago, seven said:

Thoughts on something like this?

LighTech D004 Rear Axle/Swingarm Pivot Nut

---

LighTech D004 Rear Axle/Swingarm Pivot Nut Manufactured in Italy from Hi-grade Aluminium, LighTech Special nuts are individually engineered to ensure quality and fit.CNC Machined from Billet...

Is aluminum a bad choice for tis application?

It won't last as long.  I wonder if it's 7075 or 6061.  6061 is no longer anything special.  I would hope it's 7075.  Seems it would need a locking mechanism.

[seven]

Couple questions that are not clear to me after reading through this thread:

Is the stock nut a locking nut? It sounds like it is with some sort of tabs that lock it?

Besides using a nyloc nut, or the titanium nut, what other options are there? What is the preferred Class/Grade for the nut?

Is the real issue the axel material being too soft? I see some people talking about buying an R6 axel but it doesn't sound like it is made of anything different.

[blackout]

2 hours ago, seven said:

Couple questions that are not clear to me after reading through this thread:

Is the stock nut a locking nut? It sounds like it is with some sort of tabs that lock it?

Besides using a nyloc nut, or the titanium nut, what other options are there? What is the preferred Class/Grade for the nut?

Is the real issue the axel material being too soft? I see some people talking about buying an R6 axel but it doesn't sound like it is made of anything different.

The stock nut is a metal tab locking nut.  The smallest amount of dirt will seize it to the threads of the axle.  That's why cleaning with wd-40 before touching it has worked so far for me.   

The other options would be safety wire or cotter pin on a castle nut.

It's quite possible Yamaha wants the axle material "soft" so that it is more ductile and resistant to breaking.  A harder material can be more prone to complete failure instead of bending.  Harder is more brittle at times.  My guess is the R6 axle is made by the same supplier and same material as the Fz-07 axle.  Not sure why Yamaha would spec otherwise.

My thought is that grade 8.8 and up is fine.  Grade 8.8 metric is similar to grade 5 SAE.  I had no problem running grade 5 bolts all over the suspension parts on my race car.

[Yakko Warner]

I replaced my oem Fuji nut with a nylock nut, hoping to avoid this problem.  But my hopes were dashed last weekend.

I'm guessing the axle threads were already weakened by the oem nut, and further loosening and tightening finally deformed them until the nut seized.

Thanks to everyone who posted about this happening to them, and how you removed the axle.  If I had not been familiar with this problem, I may have had a heart attack when I saw this, and panicked because I didn't know how to fix this.  Instead, I recognized immediately what happened, and read the threads here about how to remove the axle.

I decided to try thomascrown's Dremel suggestion, and it worked great.  Thanks again everyone, and thanks cruizin for this forum!

[blackout]

12 hours ago, Yakko Warner said:

I replaced my oem Fuji nut with a nylock nut, hoping to avoid this problem.  But my hopes were dashed last weekend.

I'm guessing the axle threads were already weakened by the oem nut, and further loosening and tightening finally deformed them until the nut seized.

Thanks to everyone who posted about this happening to them, and how you removed the axle.  If I had not been familiar with this problem, I may have had a heart attack when I saw this, and panicked because I didn't know how to fix this.  Instead, I recognized immediately what happened, and read the threads here about how to remove the axle.

I decided to try thomascrown's Dremel suggestion, and it worked great.  Thanks again everyone, and thanks cruizin for this forum!

That sucks.  I'm surprised it happened. 

[Pursuvant]

On 12/4/2020 at 8:27 AM, blackout said:

That sucks.  I'm surprised it happened. 

Here is the mildly scary part - the nylock nut in the picture is the one I posted as the "solution" to fuji nut siezure - and Yakko still had a failure. So question becomes "was the axle damaged by the fuji nut before the switched C19 hardened nylock was put on, or is this happening because the axle itself is inheritantly soft/flawed?"

Or is it the 68 ft-lb torque is just too hot for the axle. I think I'm going to back the axle nut torque off to about 52 ft-lbs for awhile and watch it closely.

This Belmetric nut is no longer recommended - it too has seized under work stress

Edited December 19, 2020 by Pursuvant

[mjh937]

@Pursuvant, I think the material the nut was made of is not up to task.  I do not see how the axle would cause the nut to split like that.

[Pursuvant]

1 minute ago, mjh937 said:

@Pursuvant, I think the material the nut was made of is not up to task.  I do not see how the axle would cause the nut to split like that.

The nut in the picture is after it has been cut off the axle with a dremel tool.

What we want to know from Yakko is, are the threads fouled on the axle, the nut, or both.

That's a C10 hardened steel nut

 

[mjh937]

Got it, disregard my comment then.  I thought the nut had split, which was rather disconcerting. 

[blackout]

1 hour ago, Pursuvant said:

Here is the mildly scary part - the nylock nut in the picture is the one I posted as the "solution" to fuji nut siezure - and Yakko still had a failure. So question becomes "was the axle damaged by the fuji nut before the switched C19 hardened nylock was put on, or is this happening because the axle itself is inheritantly soft/flawed?"

Or is it the 68 ft-lb torque is just too hot for the axle. I think I'm going to back the axle nut torque off to about 52 ft-lbs for awhile and watch it closely.

 

Probably a combination.   

To solve the problem, a little less torque, make sure threads stay clean, and don't use any kind of metal locking nut.  

[blackout]

Was hoping this would have been less expensive, but might be a good tool to add if you work on bikes a lot.

[Pursuvant]

12 minutes ago, blackout said:

Was hoping this would have been less expensive, but might be a good tool to add if you work on bikes a lot.

What a great way to clean, and if you feel any real resistance, detect threads that are in the process of deforming, thx blackout

[blackout]

55 minutes ago, Pursuvant said:

What a great way to clean, and if you feel any real resistance, detect threads that are in the process of deforming, thx blackout

Years ago building my race car, I came across a whole batch of fine thread 5/8" bolts that were heavy on the zinc coating.  Nuts would not thread smoothly on any of the bolts, so I used one of these to clean the bolt threads nicely.

[Pursuvant]

On 12/4/2020 at 11:26 AM, blackout said:

Probably a combination.   

To solve the problem, a little less torque, make sure threads stay clean, and don't use any kind of metal locking nut.  

I have backed off the belmetric C10 nylock nut, inspected, wiped clean and torqued to my new speck, 58 ft-lbs. Everything felt normal backing off and re-torque-ing.

Edit - This Belmetric nut is no longer recommended - it too has seized under work stress

Edited December 19, 2020 by Pursuvant
Speeeallinng horibla

[blackout]

36 minutes ago, Pursuvant said:

I have backed off the belmetric C10 nylock nut, inspected, wiped clean and torqued to my new speck, 58 ft-lbs. Everything felt normal backing off and re-torque-ing.

I'm going to watch it closely for the next 100 miles, then back it off again to 52 ft-lbs.  That's just my "guess by feel" a better torque, but if someone with more expert in industrial or mechanical engineering has a recommended torque, please jump in here and let me know.

I'm going to do my best, to never have another axle/nut uncaused seizure, ignoring Yamaha's specs as necessary.

With clean threads a lighter torque can give similar effective torque values.  The effective torque value being the clamping force that the nut is providing to the assembly.  So keep the threads clean and you are good.  This is why ARP fasteners gives torque values using their lubricant.  It assures you get the exact needed clamping force for a given torque value.

[Pursuvant]

50 minutes ago, blackout said:

This is why ARP fasteners gives torque values using their lubricant

Thx blackout for good info. That's another good topic, I was taught by older brothers to clean axle threads but not use grease or antisieze on motorcycle axle nut. But I don't know why?

What do you think? Does lubricant increase chance of axle nut walking off? How about anti-seize?

I use anti-seize on other nuts especially where exposure or hi-temp is present with no worries.

And that Yami spec of 68 ft-lbs of torque on the oem fuji nut - doesn't that seem excessive?

Edited December 5, 2020 by Pursuvant

[blackout]

19 minutes ago, Pursuvant said:

Thx blackout for good info. That's another good topic, I was taught by older brothers to clean axle threads but not use grease or antisieze on motorcycle axle nut. But I don't know why?

What do you think? Does lubricant increase chance of axle nut walking off? How about anti-seize?

I use anti-seize on other nuts especially where exposure or hi-temp is present with no worries.

And that Yami spec of 68 ft-lbs of torque on the oem fuji nut - doesn't that seem excessive?

Good question.  If its safety wired or clipped a lubricant could be used without worry.  But otherwise, I would be nervous.

For this application,  just make sure threads are clean.  I like WD40 for cleaning and then wipe dry if not safety wired.  That's just what I always have around.

[blackout]

68 ft-lbs sounds about right for an 18mm fastener.  You can google generic torque values which simply go up as fastener diameter increases.  They can obviously handle more torque as diameter increases.