Drive shaft pinion wear!!!

[Swinborg]

Right gents,

Here is something I really don’t understand.

I took apart the rear trans to régresse etc 400 miles ago, and as I am heading out on a 4,000 mile repund trip I thought I would just check it. 

The spines are red with gauling dust, and the M77 assembly paste has gone .  I am 100% sure I put a lot of M77 on it and the remainder of the grease has turned also solid and flaky.

Can someone tell me what’s happening to the grease and how do I stop this in future.  Remember it’s only done 400 miles since last check!!!

Photos attached

[Chrisj CMA]

Assembly paste is way too dry in my opinion. I would use a tiny bit of that there paste just for the moly content and then fill the female side of the final drive with a good water resistant grease. Same thing for the pinion cup just a bit more sparingly with the grease there.

[98valk]

from my post  https://www.valkyrieforum.com/bbs/index.php/topic,116696.40.html

So my conclusion is to make sure the U-Joint splines are correctly lubricated, to prevent the drive shaft to final drive splines aka spline coupling (SC) from wearing out. I also installed a new driveshaft to spline cup seal every other tire change.

The SC in a perfect application would have zero forward/rearward movement and would be submerged in oil which would result in zero wear and fretting. Fretting is a type of corrosion which gives that rust powder look. Is not from water intrusion. In some applications they actually glue the splines together to stop movement.

Honda provided the locking spring clip on the SC end of the drive shaft to help reduce movement of the SC, but it is still not a solid zero movement connection. So this is where the lubricated U-joint splines come into effect, thereby doing all of the movement, to reduce or actually eliminate any SC movement.

In a few of the links I provide it is stated that the SC splines should be hardened to greatly reduce wear.  Did Honda do this to the parts?

In my case I inadvertently mixed greases with different bases for the u-joint splines, by re-greasing and not cleaning off the old grease.
My fault, at the time, I didn't realize they had different bases. So what happened the greases started to dry out and not provide the easy sliding movement as needed and the SC failed in 17k miles.

For re-installing the U-Joint boot I coated the inside lips with silicone grease and it pops on with zero problems. suggest not to use a silicone spray which has petroleum products in it and other things which could degrade the boot material.

So to bring this all together, proper lubrication of the u-joint splines is extremely important and should be done every tire change to protect the SC. 
This time I used moly bearing chassis grease for the U-Joint for even more friction reduction and easier sliding.

For the SC I mixed TS-70 moly paste with some high temp grease so there would be about a 50/50 moly to grease ratio as recommended by the Dan Foss pdf which is a much higher percent of moly than the 3% moly grease the Honda manual calls for.

The following documents have some very good info about SCs and lubrication requirements.

https://www.machinerylubrication.com/Read/693/fretting-wear

https://www.powertransmission.com/issues/0214/spline-couplings.pdf

https://assets.danfoss.com/documents/76142/AI152986482538en-000304.pdf

https://www.eng-tips.com/viewthread.cfm?qid=423609

https://gearsolutions.com/departments/tooth-tips-a-brief-overview-of-splines/

https://www.eng-tips.com/viewthread.cfm?qid=383504

[Swinborg]

So what do guys recommend for an off the shelf grease?

[98valk]

https://www.tsmoly.com/grease-spline-grease-p-367.html

https://www.tsmoly.com/grease-moly-grease-contact-beemershopcom-info-p-251.html

[RonW]

I've been using Belray waterproof grease because its reputation to stick (marine applications). Even 100% moly isn't worth anything if it rubs off. I mix in some moly paste. However, 98valk's warning about different bases not working together got me thinking. I don't know what base Belray uses and what base is in the moly paste or if they're compatible.

[steveB (VRCC UK)]

Swinborg - you've used an assembly paste not a lubricating paste. in the UK use MolyKote Gn-Plus. Buy it from cromwell.co.uk (next day delivery) or any engineers supply. FWW its a recommended lubricant in Hondas workshop manual and there is no mention of mixing with grease.

[RonW]

Belray doesn't have any moly in it. That's the reason for mixing in moly. Would Belray waterproof grease work alone? I don't really know but it would weigh heavily on my conscience if it didn't. If I hadn't heard about Belray on the forum many years ago, I'd probably wouldn't be aware of it.

[Jess from VA]

I also use a small amount of moly paste (first) then liberally gomm lots of Belray waterproof grease in there (so much it flies out some for the first couple rides, and wiped off), and I've never had any trouble with the fretting red rust, bad wear, or anything else.  (Knock wood)

105K and 65K on my bikes, and no new parts ever needed (except one Ujoint).   

[Swinborg]

Man have I been down the rabbit hole with this one!

Done a lot of talking to sales reps and lubricant companies including a lot of chat of forums.

What I have gleaned is the M77 was a rush job when the M60 ran out and my failure is not unique - it drys out and balls/flakes running metal on metal.

I spoke to really helpful guy who runs a st1300 shop here in the uk called bikequip - he runs tours and has also seen same thing.  Up shot is the moly paste is to be used sparingly as it can overheat and degrade.  Grease is also to be avoided as it will dilute the moly on the contact faces.  Maybe ok to use as a sealant, but defo not to be used directly in gear faces.

Looked into silicone based products - but again they are not designed for higher temps.  So mineral or lithium based carriers are recommended.

I have two products on order the molykote and Rocol offering.  I will do the same, put 400 miles with both and see which works.

[Bagger John - #3785]

Yamaha has a good moly grease. I used it with my C14s and they impose the same - possibly higher - drive train shear loads as the Valkyries do.

I also have a few tubes of Honda Moly Paste squirreled away. I mix a little with the Yamaha product then apply to splined surfaces. Seems to hold up well.

[rug_burn]

(To turn an old turd over for a new stink):

    ....Or you could just make sure those two holes in the pinion cup are open and clean  (using a small stick it necessary), and you will have a constant bath of 90w gear oil lubricating those splines.   Top off the rear drive when it's leaning over on the kickstand.
     You'll hear a bunch of guys claim this is not the way it should be done, and then go on speculating 'Gee, I wonder what those two holes are for...'       But no, it's easy: those holes are there to keep those splines lubed.  They're not there by accident or some mysterious coincidence.   Just don't plug them up with dried out grease.
     The thing is that keeping the pinion cup packed with fresh grease works okay, too, but only for so long.  It's actually a higher maintenance and poorer way to lube those splines.
     
      When it comes to the splines on the rear wheel drive flange, you got no choice, but I wouldn't overdo the moly.    I don't even use moly at all, just some good high quality real sticky wheel bearing grease.
   

[98valk]

(To turn an old turd over for a new stink):

    ....Or you could just make sure those two holes in the pinion cup are open and clean  (using a small stick it necessary), and you will have a constant bath of 90w gear oil lubricating those splines.   Top off the rear drive when it's leaning over on the kickstand.
     You'll hear a bunch of guys claim this is not the way it should be done, and then go on speculating 'Gee, I wonder what those two holes are for...'       But no, it's easy: those holes are there to keep those splines lubed.  They're not there by accident or some mysterious coincidence.   Just don't plug them up with dried out grease.
     The thing is that keeping the pinion cup packed with fresh grease works okay, too, but only for so long.  It's actually a higher maintenance and poorer way to lube those splines.
     
      When it comes to the splines on the rear wheel drive flange, you got no choice, but I wouldn't overdo the moly.    I don't even use moly at all, just some good high quality real sticky wheel bearing grease.
   

if one has gear oil going into the spline area that means the inner oil shaft seal has failed and should be replaced. looking at the cut-away drawing in the tech manual, the holes are not a direct path into the gear oil area.
A honda engineer would not design the final drive spline area to have grease and oil mix together.

[Rio Wil]

I think you need to look at a final drive. The oil seal in the front of the drive about even with the threads on the pinion shaft is on the front side of the holes in the cup.  Any one have a cup that shows seal marks on it?

[98valk]

I think you need to look at a final drive. The oil seal in the front of the drive about even with the threads on the pinion shaft is on the front side of the holes in the cup.  Any one have a cup that shows seal marks on it?

I have one that shows seal marks. manual calls for the seal to be filled with grease before installing the cup. the angled hole is to allow grease to be added during a tire change without having to remove the cup.
a spline coupling which the cup and axle shaft are best install is the coupling submerged in oil, second best is almost or zero movement and high % of moly grease.
some have posted they over fill the final drive with gear oil so it goes into the cup. problem i see with that too high level of gear oil results in the oil being churned and creating air bubbles which do not lubricate the gears.

[mello dude]

This has been banged on over and over. Consensus of multiple forums is that the new M77 wont cut it.
But use of the Locktitie moly is fine..