Drivetrain lack of lubrication

[SoCalFJR1300]

I would like to know the answer

I think the answer is, lube if you want, if you don't want to, don't.

 

[Top_Speed1]

Anyone have any pictures, or accounts for that matter, of a failed drive-shaft spline on an FJR? Not talking about one that rusted and cant be separated. Looking for one that has actually failed. Striped splines. No more drive.

I have proof!!! On my old BMW K1100! Ate the splines right out of the clutch disc, round hole. Made my output shaft splines look half eaten. And thus is the reason I will NEVER again buy a BMW.

If you don't lube the output shaft splines yearly on those K-motors, you're screwed. That is an $850 job done my Beemer (back in early 2000). It took me an entire weekend to remove the entire rear of the bike, tranny, and to remove ABS lines rebleed, etc. Not a fun task for lubing splines. This is why I now own my second FJR.

Okay, but not examples on an FJR and nothing to do with rust, just lubrication....

Must be DawgyPileFriday!. I frequent a few restaurants that I don't like every dish on the menu, certainly not a reason for me not to go back to them as they have some really good entrees too!

My K16 rear... Single A-Arm/Drive, rear wheel dismounted in about a 100th of the time of the FJR's. Gear pumkin exposed and easily taken down in about the same time as a FJR. All in all, my BMW is quicker and so easy to maintain BUT certainly not anything to base my selection of a ride or not.

~~!!~~

I've been following this topic, trying to learn and gather in info. Billy and Fred need to sit down, rehash this with maybe a cold pint (or two). No name calling, both dudes are really great guys with a lot in common, and... they're friends for cripes sake!

 

[Fred W]

I would like to know the answer because I do not think SkooterG is the final authority on this issue....but I would trust your opinion if you would take the time to remove the punkin, test the spring strength, and critically review the questions/comments that have been raised.

I am willing to do that, but can't get to it in the next few days.

I've been following this topic, trying to learn and gather in info. Billy and Fred need to sit down, rehash this with maybe a cold pint (or two). No name calling, both dudes are really great guys with a lot in common, and... they're friends for cripes sake!

Yeah, well... I get the distinct impression that "Billy" doesn't really want to be friends anymore. Whatever... no skin off my nose.

 

[MCRIDER007]

I would like to know the answer because I do not think SkooterG is the final authority on this issue....but I would trust your opinion if you would take the time to remove the punkin, test the spring strength, and critically review the questions/comments that have been raised.

I am willing to do that, but can't get to it in the next few days.

Great! There certainly isn't any hurry since we have been getting by with the correct/incorrect info for years.

 

[Constant Mesh]

I continue to believe there's no front to back movement in the driveshaft once the pumpkin is firmly bolted to the swingarm. The spring at the rear of the driveshaft is there to provide a small forward force at all times to the driveshaft and the U-joint. The U-joint is not secured on the engine's output shaft with any fastener, etc. It remains in place solely from the small forward force it receives from the driveshaft.

If indeed the forward end of the driveshaft did move a bit front to back there's nothing to stop the U-joint from moving front to back on the engine's output shaft as well.

I contend there is no front to back movement.

The splined rear end of the driveshaft has a peculiar roundish, oval profile because it allows the driveshaft to be oriented at a slight angle from straight ahead. If you look carefully you'll notice that the driveshaft veers slighty to the right as it leaves the rear drive going to the U-joint. It's a small angle but it's perceptible. The odd shaped rear spline allows for small angle deflections. Any significant angle would require a U-joint.

And we know that the driveshaft gear coupling at the drive must be oriented straight ahead at a right angle to the rear wheel axle.

https://www.fjr-tips.org/maint/spline/SkooterG/coupling101.html

Notice the odd shape of the rear splined coupling.

 

[Fred W]

MCRIDER asked for it, and I (unexpectedly) had some time today, so it was time to dig into the mechanism and try to get some more details about the driveshaft spline operation and maintenance.

Let me preface this by telling you that my '05 FJR has roughly 90k miles on it. I have never performed any maintenance of any kind on the universal joint, as I have always thought that it is not required. The last (and only) time that I even removed the drive shaft was at about 15k miles and I did grease the forward splines lightly at that time.

I ride my bike through as much of the New England year as I can. This means that the bike sees salty road spray conditions during the winter months. Some of the following photos will make some of you queasy, but rest assured, my bike, and its driveshaft are perfectly healthy. So let's dig in...

First thing I did today was to remove the left side rider's foot-peg/shifter plate assembly to gain access to the U-Joint area. Here's what it looked like before doing anything:

This will probably be enough to throw some AR maintenance freaks into catatonic shock. The Universal joint (left of the black plastic) has a nice ferrous oxide patina (aka surface rust) and the spline to U-joint yoke interface is covered in fluffy road spooge.

Before going any further I cleaned up the spline interface area from the outside (without disassembling anything) so we could see what things look like at the driveshaft to u-joint interface.

Now you can see that there is an external Cir-clip on the driveshaft and that the shaft is fully engaged into the female splines of the U-joint yoke up to that clip.

Next I removed the rear wheel and positioned a jack stand (with a small wood shim) at the normal "fully extended" position underneath the swingarm to allow me to disconnect the two suspension "dog-bones" freeing the swingarm to move...

After the dog-bones were removed I was able to raise the swingarm and stick one 2x4 block in sideways and a second one on end, to raise the swingarm up ~ 5" (3 1/2" + 1 1/2"), roughly the full stroke of the rear suspension at the axle. (yes, the little shim is still stuck in the jack stand under those big blocks)

And here is the result at the driveshaft to U-joint spline interface. Note that the driveshaft is still fully engaged up to the cir-clip

So, from this we can conclude that the splined shaft does not slide in and out of the female U-joint splines during suspension articulation.

Next I loosened the four acorn nuts that hold the rear "pumpkin" to the swingarm. When I did loosen them the weight of the final drive pulled itself away from the swingarm. By holding the final drive up with my hands and trying to push it forwards I could feel that that cir-clip was hitting against the U-joint about a millimeter or two before the drive was butted up to the swingarm housing. I tried to get a photo of the gap, but I was working alone and ran out of hands.

I could push the assembly in and overcome the spring force. It is not that stiff of a spring. In fact, when reassembling later, when I finger tightened the top two acorn nuts the weight of the FD hanging on the top two studs was enough to compress that spring. But when it is in your hand you can definitely feel the shaft contact at the front end before the surfaces are mated.

For posterity, this is what a drive shaft's splines looked like when extracted after ~70k miles of no regular maintenance.

Oh the horrors!! But don't fret, that is just some old brown grease on there, not rust. Here's what it looked like after a spritz with WD40 and wipe down with a towel (no wire brushing or abrasives of any kind)

No rust there. Those splines are fine and dandy, as are the female side splines in the U-joint.

Also, in the FWIW department, I flexed the U-joint around in both axes to test the yoke bearings and it is still moving silky smooth, even with all the surface rust on the outside. There are grease seals holding the grease inside those bearings, so cleaning the outside of a U-joint will do nothing for those bearings.

If you do opt to clean it up, be very careful not to allow any solvent or brush bristles to violate those seals or else you probably will have U-joint problems in the future.

Now as for that "compression spring" that SkooterG showed us at the rear end of the shaft. Yep, it is definitely thrusting the driveshaft forward out of the final drive and pushing the shaft to be fully engaged at the forward splines in the U-joint.

Here's a view of the driveshaft relaxed showing how far the spring pushes the shaft out through the oil seal.

Yes, yes... more of that lustrous patina back here too. So what? I didn't even bother to do anything about any of it. Won't affect that driveshaft in the least.

Here I am manually pushing the shaft down (back) into the pumpkin as far as it will go. Note that it isn't all that much total stroke, maybe a total of about 4-5mm. Kind of makes sense since we are only using a couple mm of compression to engage the shaft fully at the opposite end.

So there you have it. Hopefully this conclusively answers all those lingering questions and doubts about the driveshaft and its splines.

In summary, I will repeat myself: There is no motion in the forward driveshaft spline joints. There is no need to lubricate those splines on a regular basis. Greasing them at assembly is enough to keep them from rusting up and will allow them to be easily disassembled in the future.

 

[yamafitter]

Thanks for all the work Fred but what we had here was a failure to communicate. As you mentioned there is a small gap between the front of universal and the seal of the output shaft on the motor. You also made mention of the fact that there was very little spring tension pushing the drive shaft forward. It is still my contention that there is a small amount of fore and aft movement under rapid suspension movements otherwise why would Yamaha go through the expense and bother of designing a system that allows for some float in the fore and aft direction? You were addressing just the drive shaft spline where it goes into the rear of the universal coupler but I was addressing the entire driveshaft assembly relative to the output shaft on the motor.

If there was absolutely no movement why have a spring and if it is the spring's job to cushion all the movement would not the spring have to be much stiffer to ensure there was no movement at the universal end of the drive unit? If the was no fore and aft movement at the universal end of the driveshaft why would Yamaha not just bolt the universal to a flange drive similar to the universal receiver on your car's rear end. That would be a far cheaper arrangement then the double splined coupler used at the front. At first glance it would seem that the entire design is to allow for some fore and aft movement.

Even if you don't want to accept any of that as you noted that entire area at the front of the driveshaft is in a rather harsh environment and without any corrosion protection it may become difficult to remove the driveshaft should the need arise to remove the final drive from the bike. For this reason alone adding a small bit of a quality waterproof grease on the splines would go a long way to ensuring a easier time servicing the final drive which brings us back to the original post of this thread.

My apologies for any misunderstandings but I still hate the Bruins.

 

[rbentnail]

Thanks for all the work Fred and what we had here was a failure to communicate.
You were addressing just the drive shaft spline where it goes into the rear of the universal coupler but I was addressing the entire driveshaft assembly relative to the output shaft on the motor.

+1. One point you did not address Fred is the universal joint-to-output shaft connection. I suspect it was like the rest of the assembly but I was curious as to how it would look.

And in keeping with my own tradition I felt this thread warranted a change in my signature. Let's face it- a man wastes his time and pulls sections of his bike apart just to prove to someone else he's right and everyone else is a doofus. Really? Talk about anal, on both sides of the fence. Whatever, nevermind. So I added 'splines'. I'm hoping now that an admin will have the decency to lock this thread.

 

[Fred W]

Thanks for all the work Fred and what we had here was a failure to communicate.

Well since communication involves both transmitting and receiving, I guess that you are right. But I think the error was entirely on the receiving end this time.

As you mentioned there is a small gap between the front of universal and the seal of the output shaft on the motor.

Huh? I never mentioned any such thing.

This entire discussion has revolved around the often repeated need to pull the driveshaft and lubricate the splines at the forward end. I've never even mentioned the forward side of the U-joint.

But, since you now bring it up, and FWIW, I did not even bother removing mine for exactly the same reasons. It does not move fore and aft either. It has the same spring holding things forward.

You also made mention of the fact that there was very little spring tension pushing the drive shaft forward. It is still my contention that there is a small amount of fore and aft movement under rapid suspension movements otherwise why would Yamaha go through the expense and bother of designing a system that allows for some float in the fore and aft direction? You were addressing just the drive shaft spline where it goes into the rear of the universal coupler but I was addressing the entire driveshaft assembly relative to the output shaft on the motor.

I say your contention is wrong. Why would the speed of moving the swing arm change the geometry?

Very little spring tension is needed because very little (if any) movement is generated at the shaft lengthwise during suspension movement. As I have said all along the allowance for movement (small as it is) is all at the rear end of the driveshaft where the (much larger) splines are bathed in wonderfully slippery gear oil. The spring at the rear ensures that all of the components at the front end, including the universal joint to engine output shaft joint you now bring up, has no slack, and that all of the slack in the entire driveline is at the back end where it is well controlled and lubricated.

But I still contend that there is minimal shaft motion generated via suspension movement because they also arranged for the pivot of the shaft (at the U-joint) to closely coincide with the swingarm pivot. It is a masterful example of engineering, IMO.

If there was absolutely no movement why have a spring and if it is the spring's job to cushion all the movement would not the spring have to be much stiffer to ensure there was no movement at the universal end of the drive unit? If the was no fore and aft movement at the universal end of the driveshaft why would Yamaha not just bolt the universal to a flange drive similar to the universal receiver on your car's rear end. That would be a far cheaper arrangement then the double splined coupler used at the front. At first glance it would seem that the entire design is to allow for some fore and aft movement.

The reason for the spring, even with so little movement, IMO, is because these parts do need to be assembled from pieces. And as they are manufactured, there will be minor tolerances between these machined parts. Those tolerances need to be "taken up" somewhere or there will be slack between the standing parts and they will then be free to float around, chatter and wear. This spring effectively eliminates any slack in the entire drive line. I have no doubt that if there were more variation caused by the swingarm movement that they would have just stuck a stiffer spring in there. It would be easy to do. But there isn't, so the soft spring is enough to do the job.

Even if you don't want to accept any of that as you noted that entire area at the front of the driveshaft is in a rather harsh environment and without any corrosion protection it may become difficult to remove the driveshaft should the need arise to remove the final drive from the bike. For this reason alone adding a small bit of a quality waterproof grease on the splines would go a long way to ensuring a easier time servicing the final drive which brings us back to the original post of this thread.

I have said as much all along.

My apologies for any misunderstandings but I still hate the Bruins.

Bad taste is no excuse for rude behavior, Bill.

Let's face it- a man wastes his time and pulls sections of his bike apart just to prove to someone else he's right and everyone else is a doofus. Really? Talk about anal, on both sides of the fence. Whatever, nevermind. So I added 'splines'.

So, it was a waste of time to find out for certain whether it really did work the way that I thought it did? Really? Damned if you do, damned if you don't, I guess.

So, what would you have proposed? Would it be better if people continued to blindly follow the "sage conventional advice" as laid out previously to disassemble and lubricate these parts on a regular, ongoing basis? Or to contact Yamaha and complain that their shaft splines are under-lubricated and are destined to an early demise?

I will say that it wasn't a waste of my time in my opinion. Although I theorized that this was how it works, I wasn't 100% sure. And it wasn't such a bad thing to have looked at it and cleaned it and re-greased it (for corrosion protection, not wear prevention) after all the miles and salty rides. I don't feel I wasted my time, as short as it actually was.

Now, if you feel that you have wasted your time in reading all about this, then that is your issue. No apologies here.

I'm hoping now that an admin will have the decency to lock this thread.

Yes, by all means, let's be sure to have this thread locked down now before any more horrible truths comes out to spoil our standard FJR urban legends.

 

[Bustanut joker]

All this back an' forth is giving me a headache..... Point, counter point, jab an' counter punch, thrust an' parry ..

I'm just going to drink meself silly an shave me arse.

 

[Fred W]

I'm just going to drink meself silly an shave me arse.

I think maybe the former is impossible and the latter is routine?

:lol:

 

[dcarver]

So then, at the end of the 200k mile day, I will lube my shaft every 75k just to say I can be happy and confident that, unlike my BMW brethren, ol' KrZy8 will still motivate down the road with 'quick dispatch'.

Fred, good job on looking at your shaft to determine if rust was preventing shaft penetration into the U joint.

Bill, may your shaft never rust..

LOL, this thread cracked me up!

...

...

 

[flyinlow]

Thanks for the photos Fred, really helped document what the drive system looks like. I'm in agreement that there is very little to no movement at the front where the shaft goes into the U joint.

 

[SoCalFJR1300]

Fred, good job on looking at your shaft to determine if rust was preventing shaft penetration into the U joint.

Sounds like a personal problem for BOTH parties!!

 

[Constant Mesh]

Thanks, Fred.

The definition of wasting one's time is totally up to the individual. How one chooses to use his time is a freedom I cherish.

Looking at your photo showing the removed pumpkin and the corrosion on the rear coupling makes me wonder if salty water is entering the swingarm weep hole just in front of the coupling? Instead of draining water from the swingarm it appears to be a port where water, salty spray or otherwise, may be entering and spritzing the coupling, etc.

 

[shakin]

Thanks, Fred.
The definition of wasting one's time is totally up to the individual. How one chooses to use his time is a freedom I cherish.

Looking at your photo showing the removed pumpkin and the corrosion on the rear coupling makes me wonder if salty water is entering the swingarm weep hole just in front of the coupling? Instead of draining water from the swingarm it appears to be a port where water, salty spray or otherwise, may be entering and spritzing the coupling, etc.

Hey Constant Mesh, get your own thread!

I wuz alreadi feelin bad aboot Fred(not Ed) and BillyF going the distance whens theyz were both sayin the same ting but not gettin it rite.

Your description above, using the key words and in this order; (rear coupling, salty water, weephole, coupling, port, salty spray, entering and spritzing), are just gonna get Bust wound up. Have pity on Shelia or Dolly.

Over and out! shakin ];&gt

 

[Old Michael]

"For our next trick we need to come up with a thread that will make Fred take the motor out of his bike."

 

[RadioHowie]

"For our next trick we need to come up with a thread that will make Fred take the motor out of his bike."

Go check with Wfooshee...he's primed.

 

[Fred W]

Looking at your photo showing the removed pumpkin and the corrosion on the rear coupling makes me wonder if salty water is entering the swingarm weep hole just in front of the coupling? Instead of draining water from the swingarm it appears to be a port where water, salty spray or otherwise, may be entering and spritzing the coupling, etc.

@CM - Sorry that I had not seen this question earlier.

My guess is that the (sometimes salty) road spray enters at the forward end of the shaft where it pokes through the hole in the swingarm to engage the U-joint. That hole is considerably larger than the weep hole in the rear, even though it is partly occluded by the shaft itself, and it is fairly open to spray from underneath the bike.

 

[Constant Mesh]

The swingarm weep hole just in front of the driveshaft's rear spline is quite large -- approximately 17/64" diameter. One wonders if that's large enough to promote much air flow back through the left swingarm? Seems like a rather large opening for the passage of very small amounts of liquid. One guesses they wanted to ensure that the opening never becomes plugged.

The relatively small, round opening in the front of the swingarm through which the driveshaft passes reinforces one's belief that the swingarm pivot and the U-joint are precisely aligned -- it would appear that the driveshaft doesn't move up and down in the opening as the swingarm moves up and down. If there was an up-down movement one might expect an oval shaped opening there.

Your photo showing the rear coupling with the spring fully compressed is quite interesting. The first thing I noticed is the shiny area on the large flat washer just under the circlip. The shiny area is somewhat larger than the circlip. That would suggest that there's a small side to side movement between the circlip and the washer. We know they're both rotating together so there's no rotational motion between them. Yet there appears to be some small side to side movement between them. Also, the oil line is interesting from the flexible seal. About two years after I got my FJR I removed the rear drive and extracted the driveshaft from the drive. As I recall the seal was lightly tacked to the coupling. Based on that I concluded that the seal doesn't move front to back in the coupling. It stays put and tends to lightly cement itself to the coupling. As I recall the seal is very flexible like a piece of a tire's inner tube. I'm probably fortunate I didn't damage it when I extracted the driveshaft.