Middle driven shaft end cover

Yamaha FJR Motorcycle Forum

Help Support Yamaha FJR Motorcycle Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

RzrBak

Well-known member
Joined
May 19, 2014
Messages
81
Reaction score
4
Location
Fredericksburg, VA
I'm in the process of servicing the pivot points, swing arm, drive shaft, u-joint etc. I pulled the left foot rest and this is what I saw. It looks like the middle driven shaft end cover has been milled away somewhat by the u-joint but I can't confirm this. I'm basing this on the my comparison of my picture to the one in the manual. Maybe if I had it a little more cleaned up it would be easier to tell. Anyone have any ideas?

https://

 
clean it really well before coming to any conclusions. Either carb cleaner or pressure wash then take a closer look. it looks like an unimportant 'gunk catcher' to me right now.

 
Last edited by a moderator:
I like the nice shiny Gen3 covers.

Spline.jpg


Pic was taken @ 1100 kms, note the lack of lubrication.

 
Thanks for all the confirmations that the cover looks normal. There was a ton of crap built up on everything and I've managed to wipe most of it off. I have some carb cleaner I'll use tomorrow...it's sleepy time now!

BTW, the u-joint was just as mucked up. I used some WD-40 and a toothbrush (WOW, didn't realize it's been nearly 2 hours of cleaning) and got it ready for the moly paste tomorrow.

G 'night Gracie!

 
Here are the details. Pulling the rear wheel, pumpkin/drive shaft, and then accessing that area gives you all the access you need and makes that job easy-peezy. You can also clean the removed bits while you're at it.

https://www.fjr-tips.org/maint/ujoint/uj.html

Instead of carb cleaner (NEVER a pressure washer), I used WD40. While horrible as a lube, this application (cleaning stuff and displacing water) is what it was made for.

 
Last edited by a moderator:
The best way to clean is with some mineral spirits or naptha on a rag. These are slow-acting solvents that dissolve oil and grease (WD40 contains naptha). If you're going to spray, do it from a distance that won't force any solvent into the U-joint bearings even though they are sealed...... and don't worry about getting anything squeaky clean, it really doesn't matter much, and no harm in a little greasiness on anything (call it corrosion protection). And, you can't see it when your all buttoned back up.......... Use your spline lube sparingly as you don't need it flinging around and attracting dirt and grit.

 
Lube of the splines is about the least important place you can grease the bike. There's no rotational gear mesh, the only action is the drive shaft sliding a few millimeters in and out of its socket on the u-joint as the rear suspension moves, and it would take decades, maybe even centuries, to produce any noticeable wear there on the splines. That's not to say that the shaft doesn't need to be able to move, it's just that even bone dry, the motion it makes is very small, and under no stress whatsoever, with its torsional load spread over so many splines of such great length. The other end of the u-joint, at the transmission, could be welded on for all anything cares, but that would make it harder to service when needed. Yes, if you fastened it with a set screw Bad Things would happen, but unless it sits in a salt lake for 3 months, it can never get locked up enough to do any damage, even bone dry.

I'm not saying don't grease it, but I AM saying it's nothing near as vital as everyone seems to think it is.

Everybody argues with me on that, but I stand by it.

The u-joint itself.... make sure it operates freely. It's not really a maintenance item, though, and if it fails you replace the assembly. Just be sure it works OK.

 
Last edited by a moderator:
Here are the details. Pulling the rear wheel, pumpkin/drive shaft, and then accessing that area gives you all the access you need and makes that job easy-peezy. You can also clean the removed bits while you're at it.
https://www.fjr-tips.org/maint/ujoint/uj.html

Instead of carb cleaner (NEVER a pressure washer), I used WD40. While horrible as a lube, this application (cleaning stuff and displacing water) is what it was made for.
Yeah, I'm glad it was time for bed when I posted that...that's not really what I was going to pull out and use. I had the U-joint link pulled up on my laptop and and read the WD-40 part. I was beyond tired.

It's funny you mentioned the pressure washer method. I was in a local shop yesterday getting rear brake pads and some more Moly. I asked the parts person about cleaners, told them what I was doing and out came the statement about using a pressure washer. They did caveat it with "but...don't get too close". I wouldn't even begin to consider a power washer, I have a 3000 psi model and I know what it can do even with the lowest pressure nozzle.

 
Lube of the splines is about the least important place you can grease the bike. There's no rotational gear mesh, the only action is the drive shaft sliding a few millimeters in and out of its socket on the u-joint as the rear suspension moves, and it would take decades, maybe even centuries, to produce any noticeable wear there on the splines. That's not to say that the shaft doesn't need to be able to move, it's just that even bone dry, the motion it makes is very small, and under no stress whatsoever, with its torsional load spread over so many splines of such great length. The other end of the u-joint, at the transmission, could be welded on for all anything cares, but that would make it harder to service when needed. Yes, if you fastened it with a set screw Bad Things would happen, but unless it sits in a salt lake for 3 months, it can never get locked up enough to do any damage, even bone dry.
I'm not saying don't grease it, but I AM saying it's nothing near as vital as everyone seems to think it is.

Everybody argues with me on that, but I stand by it.

The u-joint itself.... make sure it operates freely. It's not really a maintenance item, though, and if it fails you replace the assembly. Just be sure it works OK.
Yepper...I've seen all the debate on this issue. I'll just nod and keep my trap shut. What's the point in doing this
argue.gif
? I just want to ride.

I take all advice/suggestions into consideration and figure out what's best for me. It's good to know what works and what doesn't. The only way that happens if someone is willing to try it.

 
Top