Thread locker type for drive hub stud?

[Toei]

I removed the rear sprocket and one of the nuts was much harder to remove than the others - apparently Yamaha cross-threaded it.  The threads on the stud were messed up enough that new nuts didn't want to screw on to it easily.  After some serious effort I got the bad stud out.  The stud bolts are installed with some green thread locker.  

 

I have a new stud arriving tomorrow, but I'm not sure what thread locker I want to use for reassembly.  Would the factory green stuff be the equivalent to Henkel Loctite green, or perhaps it's some other mysterious Japanese product?   The Henkel product is wicking for applying to preassembled parts.  I wouldn't think one would need to use a wicking thread locker for this application?  I've never used a green thread locker so don't know how it behaves when installing.  

 

With the Henkel product anyway, the green is stronger than their blue (I typically use 243 on about everything) so that's another consideration.  I'm not inclined to use Henkel red, the only other type I have on hand.  

[Canzvt]

So, the general use of a stud and nut instead of using a bolt is to minimize wear/damage to the thread and component that the stud/bolt is threading into, and create a static thread load to the aluminum housing. This increases durability, longevity and sometimes ease of use of the various components. Studs are not normally torqued in as they usually don't have a shoulder that butts on the face of the component and puts the threads in tension (the sole reason for torqueing). The stud normally bottoms out in the hole, or bottoms out on the non-threaded portion of the stud at the top of the hole, somewhere around mid stud length. Thus the usual requirement for a thread locking compound. Once the stud is located and 'locked' in place, stud thread tension to the surrounding housing is applied by torqueing the nut, but the stud thread is in a static 'locked' situation whereby it will take much more axial load that if a bolt was being installed in the same hole and torqued to the same spec. Therefore, apply the appropriate thread locking compound, and then reassemble.

 

As for Permatex Orange, that should be fine. I personally would still use Loctite 262, as I have had a few sprocket bolts on MX bikes come loose (before using 262) and effectively machine my swingarm quite nicely, but your call.

[Canzvt]

So according to Henkel Loctite, the Loctite Green is a medium/high strength wicking formula with retaining performance somewhere between red and blue. Red and green are meant to be removed by applying heat to the area around the thread locking compound and remove with hand tools. My guess is that the factory used pre-applied green thread retaining paste (from some manufacturer) to aid in the speed of assembly. My guess is that as it was applied to the stud portion of the stud, it is not meant to be removed when replacing the sprocket. I would personally run a tap in the hole to make sure it is clean and not damaged, and then apply Loctite 262 (red) to the stud portion and install it using the double nut method. Remove the nuts, and install your sprocket as per normal using Loctite 242 (Blue) on the nut portion of the stud, and you should be good to go.

[Toei]

@Hogan  Good call on the Loctite-brand reference in the manual - I had noticed that a while back and forgot.  However, the manual doesn't reference the studs at all as far as installation into the drive hub goes (so there would be no reference to Loctite yea/nay either).  The sprocket nuts are self-locking and don't require thread locker, which may be what you are referring to.   

 

I made a run to the auto parts store planning to buy some green Loctite.  They didn't have any, but they did have Permatex Orange which I'd never heard of.  Billed as 3x stronger than blue but removable with hand tools/no heat.  I decided to go with that one.  

[Toei]

Now the question is what torque should I use for the stud installation?  The manual says 80 Nm for the nuts.  That's a steel-on-steel connection vs. steel into aluminum for the stud/hub (albeit there's a longer engagement area in the hub).  Also the nuts go on dry vs. using thread locker for the stud install.  For those reasons my SWAG is to go with 65 Nm.  Thoughts?

Edited June 5, 2021 by Toei
Revised SWAG

[Toei]

@CanzvtThanks for your thoughts on this.  Once I had the hub threads cleaned out I fit the old stud back in to see if it would bottom out at the same position as the other studs.  It does stop on the unthreaded portion as you describe, where it’s then at the same length as the others.   
 

Based on your comments I’ll install with a ratchet and go by feel, just going for snug.  

[Toei]

After thinking about this a bit more, since the unthreaded portion of the stud is not a hard shoulder I could see using high torque to install could start to force the unthreaded portion into the hole and thereby crack the aluminum hub.  Double thanks to @Canzvtfor preventing me from doing something stupid!

[Toei]

Thanks for your thoughts Hogan.  I split the difference between you and Canzvt and used the orange Permatex thread locker.  

[Rider 101]

Be a little careful when identifying Loctite by colour. The label can be erased (I have numerous bottles of all sorts of Loctite without the original labels ) Loctite 609 and 620 are green but are a super retaining compound. Don't mix them up with 290. On close tolerance parts you will struggle to move 609 or 620. I have soft sheet metal tags wire to each bottle to identify them ( from new )

My go to is 222 or 242 for everything.

[chris94]

I believe the manual says to tighten the rear sprocket nuts to 80 Nm, but you will probably strip some if you go this hard on them. Learned this the hard way, recommend just tightening them by feel.

[Toei]

On 6/6/2021 at 4:09 AM, chris94 said:

I believe the manual says to tighten the rear sprocket nuts to 80 Nm, but you will probably strip some if you go this hard on them. Learned this the hard way, recommend just tightening them by feel.

I came back to this thread because I just tried to install the rear sprocket and stripped three nuts/studs!!!!  Used a barely used Precision Instruments split beam torque wrench.  I thought something must be wrong with the wrench anyway, but perhaps not?  

 

Anyway, super disgusted with Yamaha at this point.  All that work for naught.  Can't get the nuts off, will need new drive hub at this point.  Also discovered the front axle had been cross-threaded in the fork.  I don't know if I'll ever ride this bike again at this point.  

[JayD]

Not too much help, but I’ve found this green goo on the engine cover bolts and it was terrible getting them out and back in again. Felt like I was cross-threading every single one. Had to apply way too much force to get the bolts back in, this green goo had hardened and filled the threads. From now on I’m cleaning the bolts and threads who contains this and applying regular 243 instead.

[Toei]

The sprocket nuts are marked with a 1 (Grade 1), which I believe is equivalent to bolt grade 8.8 (carbon steel).  According to this chart, appropriate torque for M10 1.25 8.8 zinc plated nut is 54 Nm!  Versus 80 Nm in the manual.  https://www.imperialsupplies.com/pdf/A_FastenerTorqueCharts.pdf

 

I suspected it before but now I'm sure: my original issue with the difficult nut from the factory was deformed stud threads from over-torque, not cross-threading.  

 

This is going to be a very expensive repair, and I'm losing my favorite month of the year for riding.  There's no way I'm going to try to get all those studs out as the one I did remove was almost impossible (even the ones that didn't strip are suspect now after over-torquing), so I'm starting with a new hub.  I'll have to press in new bearing/seal, collar, install studs, etc.  All because Yamaha published an absurd torque value in the shop manual.  I now wonder how many other fasteners are subject to gross over-torque if the manual values are used?

Edited June 9, 2021 by Toei

[Canzvt]

Sorry to hear your plight Toei. I believe you can save the original hub, (and riding month) by removing the hub from the wheel, and remove any bearings/seals from the hub, and put it in an over to about 125C. (the cook in the kitchen might not like this part...) This will release the thread locking compound, and the studs will come out easier. Replace them with new ones, and torque to your above noted spec using the orang thread locker on the stud body, and 242 (blue) on the nuts.

 

As for the front axle, it is VERY easy to cross thread this one. Any force whatsoever if the thread is not lined up properly will start the misalignment, and hence damage to the thread. Try and find an appropriate thread tap, or thread chaser to try to recover the fork thread. I don't recall if the front wheel was installed at the factory or at the dealer, but if you have had a tire change, I could see how this is possible. PM me if you want some pics of a do-it your self thread chaser if you have trouble. Wish I could help you in person, as I know this is frustrating, but it is recoverable.

[Toei]

@Canzvt Thanks for the supportive suggestions.  Since three of the studs are stripped they’d have to have nuts welded on to get them out.  I’d have to find someone and pay them to do that.  Not sure I want involve anyone else as it’s just another variable out of my control and opportunity for something to get screwed up.  

 

One of the fork stanchions had a ding in it from the dealer, so I had it replaced under warranty.  The dealer likely cross threaded the axle during that job. That’s the only time the front wheel had been off.  

Edit: I might still try your idea with the oven.  I couldn’t get one of the nuts off (just spins), so I need to try something to save the sprocket at least.  Nut splitter wouldn’t work great I think due to being flanged nut.  If the green goo melts maybe I could get the stripped studs out with vice grips.  Still need to order tools for bearing removal/replacement.  

 

Edited June 9, 2021 by Toei

[Canzvt]

Once you heat the hub, grip the stud ends with good quality vice grip pliers, and they will come out. No need for welding. If you don't have vice grips and need to purchase anyway look for one of these (or similar) instead, and you might have better success removing the studs.

Amazon.com

 

 

If your dealer torqued the axle into the fork leg cross threaded, I would demand a new fork leg. See if you can salvage it, but demand a new leg.