Shaft drive moly grease mixing with Final Drive oil?

[Knapdog]

Changed my rear tyre about 2500 miles ago and gave the splines another coating of black moly grease. I also changed the final drive oil whilst I was at it.
Today I replaced the rear Shock bushes and thought that since the panniers and suspension are out of the way I'll have a look at the Final Drive oil.
Well, to me, it looks as if it's mixed with the moly.
It's blackish and and just has that appearance of moly grease being in there.
So, how has that happened and does it matter?
If it's not a problem then, in the morning, I'll put fresh GL5 oil in and be done with it.
I replaced ALL the required shaft o-rings etc around 8,000 miles ago so that shouldn't be a problem.

[The emperor has no clothes]

It’s been my experience that the gear oil darkens with miles. It’s entirely possible some of the moly got mixed in. I wouldn’t worry about it.

[Chrisj CMA]

If any moly grease got mixed in it came from the pinion cup. But as stated, it’s nothing to be concerned about.

[98valk]

universal joint very important to have fresh grease.

http://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

[Jess from VA]

proper lubrication of the u-joint splines is extremely important and should be done every tire change to protect the SC

Except my rear tires go 30 thousand miles.


Not my wheel.

[98valk]

proper lubrication of the u-joint splines is extremely important and should be done every tire change to protect the SC

Except my rear tires go 30 thousand miles.


Not my wheel.

same here. just a suggestion as when to check since everything is apart for a tire change.

[Jess from VA]

Well I completely agree.

If that rear wheel-tire is off it's time to do every bit of maintenance you can.  I've pitched brake pads with  life left in them.   

[da prez]

  Every 10,000 mile rear end service even with 30,000 mile tires. Easier in the shop than on the side of the road. 

                                                             da prez

[Gondul]

proper lubrication of the u-joint splines is extremely important and should be done every tire change to protect the SC

Except my rear tires go 30 thousand miles.
 
Not my wheel.

Then you'll likely kill your rear end as seen on many other bikes...enjoy!

[Jess from VA]

proper lubrication of the u-joint splines is extremely important and should be done every tire change to protect the SC

Except my rear tires go 30 thousand miles.
 
Not my wheel.

Then you'll likely kill your rear end as seen on many other bikes...enjoy!

No, it (they, I have 2) gets serviced at 8-10K, despite long wearing car tires. 

My rear ends are immaculate.   

I used to do the work myself, but I have a small shop with a fantastic tech that is expert on all Wings and Valks.  He was the lead tech at a big Honda dealer for years, then opened his own shop, and I went with him. 

Anybody ever need work near Fredricksburg VA, let me know.   

[Hook#3287]

proper lubrication of the u-joint splines is extremely important and should be done every tire change to protect the SC

Except my rear tires go 30 thousand miles.

Jess, how do you like the handling of that tire?

[Jess from VA]

proper lubrication of the u-joint splines is extremely important and should be done every tire change to protect the SC

Except my rear tires go 30 thousand miles.

Jess, how do you like the handling of that tire?

I love them, and I tell you it is pretty hard to even tell they are car tires and not a bike tires riding on them.  Seems to have little if any car tire "effect" in handling/cornering (like wanting to stand the bike up in leans).  I run 40-42 PSI (never one of those guys who run low pressure in car tires; I tried low pressures and to me it's squirrely/wiggly).

Though I've been on car tires (2 Interstates) for many years now.  My previous car tires were all the Goodyear Assurance Tripletreds.  Which had deeper tread, and which did have some pretty noticeable car tire "effect" in handling/cornering.  I also think they had a harder compound than these Michelin Cross Climate 2s.  

I only got them both put on last year, and don't have high miles on them at all (getting old, riding less, and shorter days).  But softer compound or not, there is no visible wear yet.  And although the bold tread wraps clear around the edge of the tire, there is also no noticeable squirrelyness or wiggle riding though leaning turns either.  So I can't be sure they will go 30K miles like the Goodyears, but I'm sure they will outlast any bike tires (and I only run Metzler bike tires (880/888s) and they never get super long life).

Finally, Michelin is a pretty good name in tires generally.  Probably better than Goodyear.

Now if they can just leave well enough alone and not change them up.  The Goodyear Assurance Tripletred was first changed up, and then discontinued.  It wasn't the greatest tire on a bike, but it got a lot of motorcycle use/press, so I followed along, and it was OK, but it went away.  With that background history, I'm really sold now on these Michelin Cross Climate 2s, and I hope they don't go the way of the dodo bird too.

And BTW, I've always run a 205 60 car tire.  About standard height (vs lower 55s or taller 65s) and I like the wider contact patch for grip and braking and longevity.  Some car tires handled so poorly (or rubbed), so folks went to narrower 195s or even 175s for more bike-tire-like handling.  But not me.  And I've never had a 205 rub on either Interstate (though mounted clearance is always tight).