Drive Shaft -- Facts & Myths

[FJR-Richie]

I'm not sure I could be any more confused...

When I look at the Yamaha diagram on the first page of this thread it looks like there are two drive/gear couplings on the rear - one is forward of the oil seal and the second is aft of the oil seal - there do not appear to be any part number idenitifications so Im not sure what this means....

 

[radman]

I can understand them putting a leak back there so that that end gets lubed-then again, sounds like earlier rears were dry, in the Venture and Vmax-both of which use this drive or very similar versions-thats why I wonder if they may have used 2 versions of this unit in FJR production, but I just don't know for sure if this is the case. Wouldn't surprise me though-and it would explain why different owners are seeing different things.

 

[SkooterG]

I seriously doubt there are different versions on the FJR. That makes no sense to me. I think prior to this, nobody was really looking for the right detail, hence, the variance in reports. That, and not all are techies.

Also, this whole ordeal has awakened some long dead brain cells relating to memory. I believe this was all covered a couple years ago. As bounce alluded to early in this thread, there was the exact same discussion. And now, I believe I remember somebody posting they had taken it apart and found the exact same thing I did - passages for final drive oil to lubricate the splines.

One good thing out of all this. I have answered my question as to where the occasional nasty black splooges on the rear wheel are coming from. It's final drive oil that gets past the seal and eventually works its way down to the weep hole in the swing arm. Not grease from the splines at the wheel/final drive interface as some have suggested. Piccies I will post later will show this. Not a big deal, as its not much oil, but enough to make a bit of a mess on the rear wheel occasionally. And, so while its not necessary to pull the driveshaft out to grease the rear splines, it is probably beneficial to pull it so one can grease the oil seal as the service manual states to do. I am guessing that greasing it on a semi-regular basis will keep final drive oil pass-thru to a minimum.

 

[radman]

And, so while its not necessary to pull the driveshaft out to grease the rear splines, it is probably beneficial to pull it so one can grease the oil seal as the service manual states to do. I am guessing that greasing it on a semi-regular basis will keep final drive oil pass-thru to a minimum.

Might also explain why yours was so hard to remove-as opposed to mine which, at only 18 thou, came out pretty easy.

 

[SkooterG]

Ok, as promised piccies.............

The driveshaft, removed from gear coupling. Some have had this mistakenly just fall out. I had to yank on it like I was trying to pull TDub away from some gerbils:

Front of driveshaft. Looking much better these days thanks to Warhchild's FJRTech.com how-to article and some periodic maintenance. It's a bit dry for my liking, but no corrosion and a light coat of moly60 paste everywhere. It's been a while since the last time I did a spline maintenance. Everything you see here will be cleaned and re-lubed before re-assembly:

Rear of driveshaft - first time apart in 64,500 miles No corrosion. Nothing funky. Well coated with final drive oil:

Close-up of rear of driveshaft. Splines, rubber oil seal, washer, and circlip.

Here's another shot of the rear of driveshaft/oil seal/washer/circlip. I am pulling away the outer part of the oil seal so you can see how the inner part of the seal is up against the washer. It's the washer/circlip which keep the oil seal where it belongs.

One last close-up of all these parts. Obviously, I will clean the rubber seal and re-grease.

Final drive, or "pumpkin" with driveshaft removed. Looking into the gear coupling. You can see the spring which keeps tension on the driveshaft:

Closer up, looking into gear coupling. Sorry for photo quality. I was having a hell of a time getting the proper light into the gear coupling for good photos. At 11:30, you can see one of the half moon oil passages:

I had to overexpose this photo, but at least you can get a decent view of both the oil passages (half moon shape) at 11:30 and 5:30. These are where the oil passes from the final drive to the gear coupling. When I first pulled the rear of the driveshaft out of the gear coupling, there was final drive oil pooled in this area that spilled everywhere. When I raised the gear coupling more upright, that oil drained back into the final drive.

 

[radman]

Well,I guess that settles that, then. Any more questions? Good.

 

[FJRSTAR]

IIRC, the smell of hypoid gear oil was strong, but I still recall seeing grease for some reason.

I had drained my final drive gear oil as well. I also vaguely remembering discussing this with WC about how easy it is to remove the shaft from the pumpkin on some FJRs compared to others.

Found this thread, looking for more...

https://www.fjrforum.com/forum//index.php?showtopic=6256

 

[SkooterG]

Well,I guess that settles that, then. Any more questions? Good.

Yeah, I got a question for ya:

What is the average cruising velocity of a coconut laiden swallow?

 

[FJRSTAR]

"Here's another shot of the rear of driveshaft/oil seal/washer/circlip. I am pulling away the outer part of the oil seal so you can see how the inner part of the seal is up against the washer. It's the washer/circlip which keep the oil seal where it belongs."

SkooterG,

Maybe you should go ahead and install a new seal, that one looks aged. Is there any hint of grease on those splines at the pumpkin? I seem to recall mine having grease on them. I had drained the final drive gear oil first.

 

[SkooterG]

SkooterG,
Maybe you should go ahead and install a new seal, that one looks aged. Is there any hint of grease on those splines at the pumpkin? I seem to recall mine having grease on them. I had drained the final drive gear oil first.

I don't think I need to replace it. It still seems pliable. I just need to clean it up and re-lube it. (As the service manual calls for) Just like I do for the grease seals/bearing covers mounted on the wheels where they contact the axle. I mean, it's not like I have a big problem with final drive oil leaking through. Just a little, that others (wheel splooge) get also. Clean and re-grease the seal, and I bet I will be good to go. What I think I will do however, is order a spare one from Gary McCoy for "just in case".

There seems like there may be some remnants of grease. I figure it's one of three things: 1) not grease, but dirt and gunk build-up 2) remnants of grease from initial FJR build at the factory where they may have put grease on the splines?, or 3) excess grease from initial greasing of the oil seal.

Those be my guesses. Regardless, everything is well coated with oil. In fact, it's hard to believe there could be much grease in there with the final drive oil constantly circulating. (albeit slowly)

 

[twowheelnut]

I had to yank on it like I was trying to pull TDub away from some gerbils:

I am duty bound as a member of PETA, to keep you homos away from the small house pets, sheep, goats and certain members of the whale family. That's why I hold onto the little critters so tightly. I can't, however, protect those poor drive shafts and axels from you and your moly, you sick bastidge! :****:

I'm glad I was right about those rear splines, though! Egg, anyone?

 

[slapnpop]

Well,I guess that settles that, then.  Any more questions?  Good.

Yeah, I got a question for ya:

What is the average cruising velocity of a coconut laiden swallow?

What, African or European?

 

[FNG]

This twowheelnut guy, does he do anything but post one liners? And not very good ones at that? And while I'm at it, radman could maybe read a manual before he posts.

 

[Groo]

Thanks for the very enlightening pictures Skoot... another activity I'll feel more comfortable doing now that I've seen what everything looks like on the pumpkin end! :clap:

 

[twowheelnut]

This twowheelnut guy, does he do anything but post one liners?  And not very good ones at that?  And while I'm at it, radman could maybe read a manual before he posts.

Hey, Gloria? Shouldn't you be on your corner? There's a guy in a '76 Coupe de Ville that'll be comin' round shortly for his Abes - as in the copper ones.

One more thing: Leave radman alone. He has serious mental problems and can't help himself. Dr. Phil has tried and even Dr. Ruth tossed in the towel. No one, it seems, can get him from watching Oprah or get him outta his high heels and garter belts. Admittedly, though, his Ethel Merman impersonation rocks!

 

[SkooterG]

Well, as the Rad suggested............I just can't let go of this one. (But I didn't start it!!!! :****: )

Anyway, since the conclusion of this little, oh, let's say adventure, is buried at the end of 4 pages of mis-information, I started a brand new thread, CLICKY HERE, to get all the pertinent info out in hopefully a clear (if not concise ) manner. Lord know's this thread has probably confused more people than it has helped.

 

[PapaUtah]

I think I can shed a little light on the confusion. From late 70’s thru 1985 Yamaha used a slightly different design for the rear end on the XS bikes and the Ventures and VMaxs. The old style rear didn’t have a slot to allow gear oil to bath the driveshaft at rear end connection. Those bikes had a grease zerk on the driveshaft tube to lubricate that rear most connection.

As most early XS, Venture and VMax owners soon learned the zerk squirted grease on the middle of the shaft and it never made its way to its intended target. Consequently, failures of the rear teeth on the early driveshafts, (especially after the rear end was mated to the mighty Venture/VMax) was all too common. If you didn’t lube that joint yearly you could pretty much kiss the driveshaft good bye at a minimum.

In 1986 the “new” style rear(and driveshaft) was put into production and remains so to this day. The same design is found on all of Yamaha’s shaft-driven street bikes, VMax, Venture, FJR. The difference between the Venture and VMax/FJR units is the final drive ratio. The Venture is a 3.33:1 unit while the FJR/VMax is a 3.66:1 unit. One more tooth on the crown wheel of the Ventures.

 

[GPRIDER]

Hmmmmmmmmmm... Well, I guess I don't have to worry about greasing those pumkin splines. Thanks for making a definitive check with your own bike Scooter.

MNFJR05, You a rekindling some memories about my old 83 Venture. I actually wore the first shaft out at the pumpkin, because I didn't realize at the time that it needed lubing. I replaced the shaft and receiver after it gave out. Needless to say that was my first experience with the problems of shaft driven motorcyles.

GP

 

[FJRSTAR]

In 1986 the “new” style rear(and driveshaft) was put into production and remains so to this day. The same design is found on all of Yamaha’s shaft-driven street bikes, VMax, Venture, FJR. The difference between the Venture and VMax/FJR units is the final drive ratio. The Venture is a 3.33:1 unit while the FJR/VMax is a 3.66:1 unit. One more tooth on the crown wheel of the Ventures.

This is the VStar 650 final drive pumpkin "cone" area. The splines have to be greased because they are not lubed by the hypoid gear oil.

There have been failures due to none or poor lubrication from the Yamaha factory and the repair manual does not address this area of the drive shaft in the regular maintenance section.

Clicky....

https://650ccnd.com/shaft2.htm

 

[PapaUtah]

First time I have seen the final drive connections on the V-Star. I hope the bigger Stars use a beefier connection back there. The early XS/Venture/VMax units had the same basic design. The drive shaft appeared more like the current design except the toothed portion was narrower, maybe 7/16” at best and the teeth were much finer and shallower. I saw many a Venture pulled apart with the same amount of rust and particles in it. The teeth would be ground down to nothing.