Grease Those Splines Boys!!!

[crazy steve]

Yeah, those splines were right at the point that a good hard powershift would probably have cleaned one side or the other right off... That would have been a 'truck it home' deal.

Another reason for not taking anything for granted on a non-running bike, or even one that is running...

[clcorbin]

That actually surprises me. I finally pulled the final drive off my 79 last year for a good cleaning and regreasing (with the correct moly grease). I KNOW it hadn't been touch in at least 22 years and at least 60,000 miles. But the splines looked brand new. The grease was nice and black there was still plenty of grease down in the splines.

I have no idea what happened to the one you showed! But you definitely got to it just before it became a broken part!

[CaptonZap]

That actually surprises me. I finally pulled the final drive off my 79 last year for a good cleaning and regreasing (with the correct moly grease). I KNOW it hadn't been touch in at least 22 years and at least 60,000 miles. But the splines looked brand new. The grease was nice and black there was still plenty of grease down in the splines.

I have no idea what happened to the one you showed! But you definitely got to it just before it became a broken part!

Howdy Clint,
I take it that you have done the maintenance on the bike for the last 22 years. If so, what sort of lubrication have you done on the rear Zerk?
The rust evident on Steve's splines looks like there was no grease put in there to start with, or else the wrong grade of grease was used to lube the Zerk. Steve didn't say how much grease was in the drive splines when he disassembled it, or what its consistency was, so we're sort of in the dark there. Motoman's due for a peek one of these days, so we'll get more data points then. CZ

[motoman]

Howdy Clint,
I take it that you have done the maintenance on the bike for the last 22 years. If so, what sort of lubrication have you done on the rear Zerk?
The rust evident on Steve's splines looks like there was no grease put in there to start with, or else the wrong grade of grease was used to lube the Zerk. Steve didn't say how much grease was in the drive splines when he disassembled it, or what its consistency was, so we're sort of in the dark there. Motoman's due for a peek one of these days, so we'll get more data points then. CZ

Lol.........somehow I knew U were gonna chime in there CZ. Give me a heads-up when U decide U wanna head this direction. Will have to remove the left-side hard case and left portion of framework, and left-side exhaust(Venturer has the same upswept exhaust as the Special). Otherwise, sittin' a bit over 81K and insides have not ever seen daylite yet......

[crazy steve]

....Steve didn't say how much grease was in the drive splines when he disassembled it, or what its consistency was, so we're sort of in the dark there...

What I found inside the drive splines looked about the same as what you'd find in a failed u-joint; a rust-colored paste, and not much of it. The splines had been lubricated via the zerk fitting, as there was plenty of grease on the outside of the coupler and inside the driveshaft tube.

Now FWIW, this bike looked like they seriously scrimped on the grease right at the factory. The forward end of the driveshaft had almost no grease on it (although no signs of excessive wear), and the same can be said for the swingarm and neck bearings. The swingarm bearings were all but dry. I pulled the driveshaft u-joint apart and found the same thing there; almost no grease. Amazingly enough, the u-joint and swingarm bearings were still good, although the upper neck bearing showed signs of moisture. I'll repack all of these before reassembly....

[WSL91]

That zerk fitting is useless.....





49K on the bike (the XJ I bought), plenty of grease in there (gobs inside the shaft tube) but it wasn't getting to where it needed to be. Looks like a good idea to pull the FD and manually lube these, ya think?

The splines inside the coupler are just as bad; too bad, the FD seems fine otherwise.. Time to go digging in the spares.

Maybe it suffers from Overuse of the throttle.

[CaptonZap]

Lol.........somehow I knew U were gonna chime in there CZ. Give me a heads-up when U decide U wanna head this direction. Will have to remove the left-side hard case and left portion of framework, and left-side exhaust(Venturer has the same upswept exhaust as the Special). Otherwise, sittin' a bit over 81K and insides have not ever seen daylite yet......

Howdy MM,
I'm leaving on a trip to the left coast on the 24th of June, so I can swing by then, or ride over before then, if you want to do it sooner. (I think the snow storms are about over for the winter.) Let me know what works for you.
And, just out of contrariness, how do you know that, while the bike was off frolicking in Arizona, the owner didn't pull the final drive and lube it?
Oh well, we'll just have to see what's what.
Later, CZ

[CaptonZap]

What I found inside the drive splines looked about the same as what you'd find in a failed u-joint; a rust-colored paste, and not much of it. The splines had been lubricated via the zerk fitting, as there was plenty of grease on the outside of the coupler and inside the driveshaft tube.

Now FWIW, this bike looked like they seriously scrimped on the grease right at the factory. The forward end of the driveshaft had almost no grease on it (although no signs of excessive wear), and the same can be said for the swingarm and neck bearings. The swingarm bearings were all but dry. I pulled the driveshaft u-joint apart and found the same thing there; almost no grease. Amazingly enough, the u-joint and swingarm bearings were still good, although the upper neck bearing showed signs of moisture. I'll repack all of these before reassembly....

Howdy Steve,
How much of the maintainence history do you know of this bike? Did you get it new?
Every drive shaft that I have seen has had the hollow, that fits over the spring on the pinion shaft, filled with grease. The picture you showed looked like there was none. Did you clean it out with solvent before taking the picture, or was it that barren when you took it apart? CZ

[DGXSER]

Honestly, to be that corroded, the bike had to about sit out exposed and unused for some time. I have never seen one corroded like that, not even my barn/field find bike that was about as neglected as any I have seen. I think that alone speaks volumes to the root cause more so than relying on the zerk.

None the less, I agree completely that greasing the FD splines manually is the only way to know the grease got where it needs to go.

[crazy steve]

...How much of the maintainence history do you know of this bike? Did you get it new?...

I bought it in Febuary used from a local forum member and he had been riding it until about the first of this year. It had the second gear issue, but the last straw for him was the number two head pipe broke and fell off on the West Seattle freeway... At that point, he listed it on CL for parts (and mentioned that here), I didn't want to see a decent looking complete bike go for parts so I bought it to rebuild. It had suffered at least some lack of maintenance (valves were waaay tight), but other than those few things I haven't found anything else seriously wrong; just the usual little stuff. He rode the bike fairly regularly (more than most would given our weather), so it hadn't been sitting and was stored indoors. He bought it (running) used from someone else a few years before...

I'll repeat, I think the problem was there wasn't enough grease put in there at the factory; the general lack of it I found elsewhere leads me to that conclusion. When I pulled this apart, the driveshaft spring came out virtually dry, coated with rust dust only. I did flush the coupler out to photograph it, but there wasn't much to clean out; some pasty rust-colored residue around the edges, but the splines had a heavy coating of rust dust only.

Again, somebody had greased the zerk; I cleaned a pretty good-sized gob out of the swingarm. Maybe you need a certain amount of grease in the coupler so any added can 'wick' in there, kind of like priming a pump.

This may have been a fluke, although I recall Three Phase had a very similar problem a few years ago when he found some major spline wear. All I know is I won't use that zerk fitting as the lube method on my bikes....

[motoman]

Howdy MM,

And, just out of contrariness, how do you know that, while the bike was off frolicking in Arizona, the owner didn't pull the final drive and lube it?
Oh well, we'll just have to see what's what.
Later, CZ

Very doubtful CZ, as the retaining nuts still have the original paint intact, plus the zerk still had the shortened black vacuum cap on it that I had put on some 14yrs. prior. Doubtful he even knew that existed. Hell, the middle drive still had the mineral 90# in it I had put in yrs. prior. Absoltely no rust on bike ANYWHERE, as you have seen, it just got rode into the ground, which is I'm sure part of why it was pumping oil in #3 hole. Matching yr./model moter I replaced it with is only 83 in production numbers after the original........likely was originally assembled the same day as my original, and shipped to same part of country. The replacement motor, IIRC had way under 20k on it, and it shows, inside and out(no cracked carb boots, case paint is as new.) Referring to Steve's comments about lubrication from factory, he IS dead-on. Fortunately, personnally knowing the owner of dealership where I bought this new in Durango, ALL new scoots that were assembled by them had steering head yoke removed and bearings packed, along with swing-arm beings, etc. before assembly. They were well aware of the lack of lubrication on all new bikes. Consequently, the steering head bearings are as smooth rotating as they were when new. All I knew back then was to give that zerk 30pumps of grease when changing oil. That's equivelant to 2oz. Figured that must have eventually found its way up the shaft to the small internal guide plate and dried hard all those years, pretty much sealing off any grease reaching the boot. Now having bike back some 7yrs. and lubing that zerk as I had always done prior, the lube will now try to squeeze past the mating surfaces where final drive mounts leaving an occassional moist area around that mounting flange after lubing and collects dirt there first. Now if that ends up being the case when CZ comes here to witness the findings, then in THIS bikes case, I have no reason to ever disturb that final drive again. With a little over 80K on the bike, CZ's and I's contention is this has been the case, along with our own theory of the zerk/lubrication thing. With his and mines ole' school experience with related situations, and the miles on the bike, if those splines we not getting lube, metal fatigue and crystalization of the splines would likely resulted before now. Either way, we're gonna find out. Who knows, I may get a handful of powdered splines. Meanwhile, until then, I have no issue with occassionaly ridin' it like I stole it, as I have always done, with a few day rides down to Durango and back,(375mi.round trip),and an 'overniter' up to SaltLake(700mi.round trip) to visit an early member from the site and his wife(DarkHorse). Be safe, ride diligently, Brant.

[clcorbin]

Howdy Clint,
I take it that you have done the maintenance on the bike for the last 22 years. If so, what sort of lubrication have you done on the rear Zerk?
The rust evident on Steve's splines looks like there was no grease put in there to start with, or else the wrong grade of grease was used to lube the Zerk. Steve didn't say how much grease was in the drive splines when he disassembled it, or what its consistency was, so we're sort of in the dark there. Motoman's due for a peek one of these days, so we'll get more data points then. CZ

I would grease the zerk with high moly grease (not the 60% stuff called for, just normal 5-6% "moly grease") every year or so. When I opened it up, the case was packed pretty full of still very black grease and the splines still had some black grease on them. No brown to be seen. I also live in a VERY dry climate, so I am sure that helped with some issues as well.

[CaptonZap]

I would grease the zerk with high moly grease (not the 60% stuff called for, just normal 5-6% "moly grease") every year or so. When I opened it up, the case was packed pretty full of still very black grease and the splines still had some black grease on them. No brown to be seen. I also live in a VERY dry climate, so I am sure that helped with some issues as well.

Thanks for the fleshout. I think we are starting to see a pattern. An over abundance of grease pumped in equates with a lubricated spline.
You don't say how many strokes of what sized grease gun you put in, but MMans 30 stroke comment shows how much he was putting in, and that the factory manual, stating that 30cc should be pumped in, is probably the correct way to keep the joint lubed. Two or three strokes won't cut it.
To look at it another way, grease developes heat when forced to shear. (Which is why you are told not to over grease critically engineered roller or ball bearings. The heat buildup degrades their performance.) If the coupling is entirerly encased in grease, when the shaft starts rotating, the grease is heated, by shearing action, the oil comes out of suspension, and flows along the surface of the parts. When the shaft stops, gravity makes the oil flow down, and it will puddle on the firm grease, seeping into the splines, and congealing around the coupling, ready to repeat the process the next time.
At least, thats the thoery.
As far as dry climate, I don't think that has a lot to do with it. A surface covered with a good coat of grease is pretty immune to moisture vapor. And, unless you are useing the bike for river crossings, and the u-joint seal is compromised, there is no liquid water in there. We're back to the old "keep the gas tank full so it doesn't breath and collect condensed moisture" scenario. If the coupling joint is full of grease, it won't breath in air, moist or dry. Hence, no rust and associated abrasive action. CZ

[XS11UFO]

Glad I saw this thread

Thanks for chatting about this guys, I found the thread after I hit the zerk fitting and decided to pull it apart. Easy to see the new grease didn’t get where it was needed, and even if it did that old grease would still be in there.

Driveshaft



Final Drive

[Guest]

Can u feel that type of wear. Mine has a litte slop when accelerating and de-celerating.