Drive Shaft -- Facts & Myths

[FJRottie]

There doesn't appear to be a seal of any sort between 'em

Item # 10 in my pic above is the bearing retainer/oil seal in the manual.

Edit - # 12 is oil seal. As per radman's next post. (online version a little different than manual..manual better)

 

[radman]

The gear set and driveshaft are well seperated by an oil seal absolutely dedicated to doing it's thing-reference #12.

 

[twowheelnut]

Huh, fancy that. I wonner why they didn't put the seal a wee bit further dow...

Never mind. The light bulb just turned on. Better git to lubin' that end of the drive shaft, soon. :erm:

 

[Bounce]

Wait a minute.  Unless I am very mistaken (wouldn't be the first time), you guys are all bonkers! :lol:
Whatever you want to call the rearward part of the driveshaft where it mates with the rear drive is most definitely lubed by the rear drive oil.  That's what the oil is in there for in the first place.  If you actually pull the shaft out of the pumpkin, or final drive housing, (as some have done accidently) it will be covered in final drive oil.

So what planet are you all from?

Back in late 2002 there was this same discussion. I stated as much as the first post in this thread (less authoritatively - more based on past experiences with other shaft-driven bikes). No one knew for sure because there'd been no tear downs of the rear assembly at that time.

I was promptly stomped into a mud puddle by the community which said that the rear spline of the shaft (not the hub splines) were lubed as part of the "pumpkin" assembly.

 

[Constant Mesh]

Wasn't trying to rile the hornets!

Looking on page 4-95 (4-97 ? in U.S. manual) of my bootleg European service manual under the heading of "Checking the final drive oil for contamination and checking the shaft drive for leaks" you can see a drawing showing the final drive's oil seals and O-rings. You can see the oil seal and O-ring associated with the pinion gear (small gear) . You can also see the splined coupling which receives the drive shaft. You can see how the coupling extends out almost as far as the four bolts which have the acorn nuts. All of the gear oil should be contained inside the boundaries of these oil seals and O-rings. What you don't see in this drawing is the oil seal associated with the drive shaft. When the drive shaft is installed the oil seal fits inside the coupling opening that you see in the drawing. It doesn't appear that anything holds the drive shaft in the final drive except for the friction of the oil seal with the coupling and maybe the tight tolerances of the splines.

If you look at page 4-104 (4-106 ? U.S.) you can see what the inside of the coupling looks like.

And finally on page 4-112 (4-114 ? U.S.) you can see the isolated drive shaft. In the text they discuss the use of lithium soap based grease on the drive shaft and universal joint splines. You can see an abrupt shoulder on the U-joint end of the drive shaft. I haven't checked but I'd guess when the drive shaft is installed in the U-joint that this shoulder on the shaft butts up against the end of the U-joint. The spring at the other end of the shaft applies constant pressure pushing the shaft forward against the U-joint.

I think what some are seeing at the weep hole in the swingarm may be liquified grease that's oozing out around the shaft oil seal. I doubt that this seal is capable of effectively containing gear oil.

 

[Bounce]

Actual photos of the U-Joint

All documented here:

https://www.bikes-n-spikes.org/maint/ujoint/uj.html

My original write up on servicing the splines is here with corrections (in bold) based on community clarifications (not just FJR Tech) at the time.

https://www.bikes-n-spikes.org/maint/spline/spline.html

 

[twowheelnut]

Hey, bounce? I have a quick question that I'm sure you're asked a lot, so please forgive, but why do you have links to the photo's in your write-ups instead of putting them on the page? Is it space related or simplicity for you or...??? Not dissing or complaining, just curious.

:dntknw:

Thanks,

TWN

 

[Sherman]

To All the Wise Elders,

Am I to infer that all bearings with built in plastic sheild caps are "sealed" and therefore there is no "re-packing." We just inspect and replace when needed? That would include the actual U-joint, and the front and rear wheel bearings (others?)

I think I have answered my own question, but I've been away from the tools for 25 years. :eh:

Bruce

 

[radman]

yes, sealed bearings are non-lubeable. It could be done with a fine needle grease fitting, but why bother? If a sealed bearing needs grease due to noise etc it's already shot, and should be replaced. A quality sealed unit will last a very long time-note that most automotive hubs used sealed bearings now that can last for a couple hundered thousand miles if you're not bouncing her offa curbs and don't let misalignment tear up tires. The u-joint can be disassembled and greased, but once again, if it indicates the need, it's junk. FJR u joints don't have a problem history, and some high mileage machines still have the original.

 

[FJRMGM]

---> "And as I said above, there is no reason to pull the driveshaft out of the pumpkin."

For several of us - we didn't have to pull on the driveshaft - it just fell out when we held the pumpkin wrong.

Be careful - only the seal is holding the shaft in the pumpkin and it CAN or WILL fall out, right on your foot if not careful.

 

[GPRIDER]

Man, this is getting kinda confusing. I've had my Venture pumkin off many, many times and it is similar to the FJR unit. However, it doesn't have a seal at the pumkin. It just slides in and out of the receiver on it, with the spring behind it. My V-MAX had the same (looked the same anyway) rear pumkin as my FJR. I never could get the shaft out of it. If I remember right it was because I didn't have a decent pair of cerclip pliers to remove the clip that appeared to be holding the seal and the shaft in. I always wondered if it needed lubing. I think I remember seeing a clip holding the FJR shaft on also. Scooter, please let us know what you find out (with Pics) if you get to yours first.

GP

 

[twowheelnut]

---> "And as I said above, there is no reason to pull the driveshaft out of the pumpkin."
For several of us - we didn't have to pull on the driveshaft - it just fell out when we held the pumpkin wrong.

Be careful - only the seal is holding the shaft in the pumpkin and it CAN or WILL fall out, right on your foot if not careful.

I thought that little C clip held it in there?

Rad? Little help here. :dntknw:

 

[radman]

That "seal" is actually just a dust boot-turns with the shaft and reciever, so it doesn't serve typical oil seal functions. The clip I don't know, as I've never had my shaft out of the final drive yet either-but I would imgine it simply locates the forward edge of the boot in place. I put a new set of Makeup Tires on today, so I'll yank the punkin and see what is what. (12,300 on the Avons by the way, rear superslabbed flat and front starting to cup and vibrate and hum, but double the life of the Stones).

 

[SkooterG]

Well, while were on the subject, here are some photos from previous maintenance I performed.

The first few piccies are from the first time I had the rear wheel off at approximately 5500 miles and 4 months after I took delivery of my brand new FJR. You will see heavy corrosion in these pics. That is why it is important to follow Warchild's FJRTech article and Bounce's write-up on the maintenance of these items. Sure, yours may be fine, but they may not be.

Forward end of the driveshaft:

Rear axle (Isn't this nasty!):

Rear or aft end of the driveshaft. Here it is going into the gear coupling, and then you can see the start of the pumpkin, or final drive:

From U-joint maintenace at a later date:

Removing stuff to get at the U-joint and tranny output shaft:

Tranny output shaft:

U-joint:

 

[twowheelnut]

So what holds the shaft in the pumpkin? The friction of all the seals, bearings 'n ****? Doesn't look like the clip does...

 

[radman]

So what holds the shaft in the pumpkin?  The friction of all the seals, bearings 'n ****?  Doesn't look like the clip does...

Nothing physically retains the shaft in the drive, other than the friction of the outer edge of the boot inside the reciever and the splines of the shaft. In fact, a spring behind the gear wants to push it forward and out of the reciever. That circlip is holding a washer then the dust seal in place. The spring keeps the shaft tensioned between the rear end and the ujoint to prevent any fore and aft walking of the shaft.

 

[Groo]

Dang Skoot, looks like you definitely got a Friday bike.... :blink:

 

[twowheelnut]

Nothing physically retains the shaft in the drive, other than the friction of the outer edge of the boot inside the reciever and the splines of the shaft. In fact, a spring behind the gear wants to push it forward and out of the reciever. That circlip is holding a washer then the dust seal in place. The spring keeps the shaft tensioned between the rear end and the ujoint to prevent any fore and aft walking of the shaft.

So, a good yank should free it from it's steely grip on the pumkin, right?

 

[SkooterG]

Dang Skoot, looks like you definitely got a Friday bike.... :blink:

You ain't kiddin!

This is what my driveshaft splines (forward end) looked like. A bloody crime!

 

[FJRSTAR]

Nothing physically retains the shaft in the drive, other than the friction of the outer edge of the boot inside the reciever and the splines of the shaft.  In fact, a spring behind the gear wants to push it forward and out of the reciever.  That circlip is holding a washer then the dust seal in place.  The spring keeps the shaft tensioned between the rear end and the ujoint to prevent any fore and aft walking of the shaft.

So, a good yank should free it from it's steely grip on the pumkin, right?

When I had mine apart recently, a little tug on the driveshaft pulled it right out so that I could check the rearward splines. Everywhere that needed lubed/greased on the my '05 driveshaft was done from the factory. I did clean and re-grease as needed where there was some minor surface rust.

At the time I did the maintenance on the shaft and rear tire swap, there had been a discussion about this same thing.

The shaft can just fall out of the pumpkin on some bikes easier than others. There is the spring that you have to watch out for as well when it does come out.