Dry rear splines answered

[Slappy]

For those of us that got bikes with dry rear splines I have the answer and its not Yamaha.

When I first got the bike, like many of us here I came to the forums for some insite into this machine. Having read about the rear splines on 06-07 coming from "the factory" dry as a bone made me concerned. So after my 600 mile service I decided that what ever oil the shop put in was not good enough. So I, at 1000 miles put in synthetic. While I was at it I decided to check the rear splines just to be sure mine wasnt dry. Well low and behold it was. So being the good forum monkey I purchased some Honda Moly60. First I cleaned the splines with brake cleaner to be sure I didnt have any contaminates in the fresh new moly. After wiping clean I began to slather that moly in and on there like a fat chick putting chocolate sauce on a sundae. I also covered the end of the drive shaft the same way and covered the rest of the shaft with Mobil1 synthetic grease to help prevent rust. Having done my first real wrench job on the bike I was feeling pretty good. After all I helped prevent premature wear on a vital part of the bike.

Along comes 8,000 miles and my Bridgstone stock tires are done. So I take it to my local shop and have him replace my tires I ordered form MotoX online. After much cursing I helped him remove the front and rear tires from my machine. After he removed my rear tire he comments to me that the rear splines are once again dry. I told him that was impossible. I had just caked honda moly in there but a few months ago. Having only had the bike for a total of 5 months and having done that oil change just two or three months ago there was no way the moly just disappeared. I looked at the rear tire and the rear end and sure enough no moly. He ends up spooging in there some water proof grease. About as liberally as I had done.

To recap, at 1,000 I honda moly the rear end, at 8,000 the tire guy greases the rear end.

Well, today, going over the bike after installing the thermostat I pull the rear tire off again. NO LUBE. However there is a fine speckling of dirt all around the lefts side of the rim. I go to wipe it off with a clean dry towel and it wont come off. I scrub and use some wd40 and it finally comes off. Its the water proof grease coming out of the joint. Since there is not seal as I ride the bike the grease or moly slowing exits the splines due to centrifugal force. Due to honda moly being silver like the rear wheel I never noticed it as it did the same thing over time. Only after adding water proof grease and having it stick and dirt collecting against the sticky stuff did I ever notice it.

I do not speak for everyones machine only mine. However, those that have this issue might try to use some water proof grease in the rear end and see if your results are the same as mine.

Question to the forum collective. What does this mean as far as rear spline maintenance? Is this something that needs to be checked every oil change and not just every tire change? I would like to hear your opinions.

 

[ionbeam]

The splines that we say should be greased are the ones where the driveshaft engages the universal joint and these splines look like this:

Picture from Yamaha FJR1300 Supersport-Touring Site

I'm betting you are talking about the rear wheel splines where the wheel engages the drive unit.

 

[meosborn]

The splines that we say should be greased are the ones where the driveshaft engages the universal joint and these splines look like this:

Picture from Yamaha FJR1300 Supersport-Touring Site

I'm betting you are talking about the rear wheel splines where the wheel engages the drive unit.

+1 IIRC, the last time I checked, mine still had grease on them and that's after about 10,000 miles since I last applied grease.

 

[Slappy]

Not the drive shaft part but the splines around the rear axle.

 

[Ignacio]

Not the drive shaft part but the splines around the rear axle.

Yeah.....those aren't the splines that we've been worried about....in fact it's not even part of the drive shaft . It's the part that connects to the "Clutch Hub" and is probably a pinion gear. I guess one can consider it a spline-to-spline connection, but definitely not the one we've been concerned about in the past on the forum. It's the splined driveshaft ionbeam pictured.

 

[lnewlf]

Don't forget to pull the U-joint anjd grease those splines too.. Spent a couple of minutes to remove the footpeg bracket and this becomes a lot easier.

 

[Geezer]

Well, if this post was about the splines which are exposed when the rear wheel is removed, where the wheel mates with the drive, then my experience is different from yours. I apply fresh grease there at every tire change, but I never found it dry in there.

If you're talking about the rear end of the drive shaft, where it plugs into the rear drive housing, I never had mine out. I do pull the drive out from the front end and grease the front splines and u-joint once a year. It was only dry the first time I pulled it out.

 

[FJRBluesman]

...I began to slather that moly in and on there like a fat chick putting chocolate sauce on a sundae.

What warpped fantasy is this? Are you talking about yourself?

Slappy - I agree with the others the rear wheel area is not the drive shaft splines we be talkin' about.

That being said, I had tons-O-grease all over mine when I relubed it, and yes it does come flying out onto the rear rim. I thought it to be oil from the pumkin as some have said that happened to them not using yamalube back there, it "leaked thru the seals" until they went back to the Yamalube. Well it's really grease, and my pumkin oil level has been fine. Not all of the grease has come off, just some being redistributed all over the place.

Good luck in keeping your rear end lubed. :lol: :rofl: :lol: :rofl:

I crack myself up! :lol: :rofl:

 

[Slappy]

Bluesman you just opened yourself up for an Odot rampage.

Its funny that for an area that takes such pressure and stress that they wouldnt have designed some kind of seal around the area to help keep the grease in there. I can only speak for me but moly only lasts 3-4K miles. Thats just nuts. The entire weight of the bike is on those splines. I guess I just need to lube and lube often. Once every tire change just isnt enough.

 

[charismaticmegafauna]

Thats just nuts. The entire weight of the bike is on those splines. I guess I just need to lube and lube often. Once every tire change just isnt enough.

Roughly 1/2 the weight of the bike is on all the rear wheel bearings (together) -- the wheel drive splines merely transmit the motive force (forward or backward).

If it makes you feel warm and fuzzy? -- lube 'em all you want....

Just clean up your mess....

 

[S76]

One thing to keep in mind is you cannot put (much) grease on an external spline. If you do, when you slide it into the outer, or internal spline, it just wipes it all off. Now you have a lump of grease all around the outside of the splines that ends up being slung outward to eventually find the rim.

Another thought, is you have to imagine what the clearance is between the inner and outer splines. Maybe a couple of thousandth's? So any amount of grease beyond that amount will just get wiped off during installation.

To grease is good. But this is one case where "If a little does a little good, then allot must do allot of good." just won't work out.

 

[FJRBluesman]

I guess I just need to lube and lube often.

Slappy - You're not helping yourself....

There is that little plastic kind of cover or flange on the outer pumkin that I guess is meant to help keep the grease from really making a mess all over the rim but, it still gets out. I haven't had it dry up like you're saying though. Do you ride in the rain a lot (yeah like that happens in SoCal)? Not sure why yours is so dry.

I'd hate to have to pull the rear wheel and relube every couple thousand miles, that's not right.

 

[Slappy]

I do not see any type of seal back there at all. Just the male female ends and the rear axle to hold them together. I have the axle torqued to spec. Thought that might have been the problem. This weekend I will do it again while others watch to make sure I am putting the rear wheel back on properly. Maybe I am missing something.

 

[rbentnail]

Many years of working on overhead cranes with splined universal joints had taught me this: moly grease bad, dry moly spray good. Search and ye shall find stuff like this https://www.superior-industries.com/dry_tra...WID=52751800021. You can find good quality stuff that dries (so it doesn't attract dust/grit), won't wash out and won't sling off. It tends to be a little pricey, but WTH, I just steal some from work.

 

[Diavalos]

Most snowmobile dealers handle the dry moly spray used to lube centrifical clutches. I'll bet it would work well on drive splines.

 

[Bustanut joker]

...I began to slather that moly in and on there like a fat chick putting chocolate sauce on a sundae.

What warpped fantasy is this? Are you talking about yourself?

keep your rear end lubed.

Sounds more like you Blusey while surfin' ghey porn.



:jester:

 

[Fred W]

Someone correct me if I'm wrong here, but I thought that the reason the drive-shaft splines are (need to be) greased is because as the rear suspension flexes up and down, the drive shaft can change length subtly. To accommodate that change in length requires that the male splines slide in and out of the female receiver in the U joint. And take note that if that happens when under throttle there could be a bunch of torque being applied through that joint coincidentally with the need to slide in and out. Hence the need for moly lube which holds up under high pressure applications.

Now, as to the rear wheel clutch hub "spline" (which appears in the parts breakdown to mate with it's female spline-ette formed into the center of final drive's ring gear? Could that be right?) once the wheel is bolted into place, there should be no lateral movement of that spline joint at all. The only load would be the rotational force being applied by the final drive. There should be no sliding between spline and spline-ette at all. So, the only need for grease there would be an anti-seize or other metal protectant from the elements.

 

[Slappy]

This whole thead was about the hub spline but Im bored at work so Ill move things along.

FredW yes the drive shaft moves in and out due to the swing arm moving up and down. That is not only why they need grease. They also need grease because they are two peices of metal meshing together and the grease prevents wear.

The rear hub spline needs grease for nearly the same reason as the drive shaft. It is two pieces of metal meshing together under pressure and the grease prevents wear.

Please someone prove me wrong here. Clean the hub out, spray some WD40 in there to prevent rust and let me know what happens over the next 20,000 miles with just regular maintenance of WD40 in the hub spline since we all agree the drive shaft splines need moly.

rbentnail I like the idea of dry moly. I never knew dry moly even existed.

 

[Fred W]

This whole thead was about the hub spline but Im bored at work so Ill move things along.
FredW yes the drive shaft moves in and out due to the swing arm moving up and down. That is not only why they need grease. They also need grease because they are two peices of metal meshing together and the grease prevents wear.

The rear hub spline needs grease for nearly the same reason as the drive shaft. It is two pieces of metal meshing together under pressure and the grease prevents wear.

Please someone prove me wrong here. Clean the hub out, spray some WD40 in there to prevent rust and let me know what happens over the next 20,000 miles with just regular maintenance of WD40 in the hub spline since we all agree the drive shaft splines need moly.

rbentnail I like the idea of dry moly. I never knew dry moly even existed.

I respectfully disagree. 2 pieces of metal that mesh together, but that do not move relative to each other, will not wear. There must be friction to wear. If there is no relative motion there is no friction, only pressure. Now, it may very well be that there is some other relative motion that I have not accounted for.

My reason for describing the motion of the drive shaft spline was to point out how different that interface is from the one at the rear wheel hub.