Mystery Metal: Final Drive

[chico]

After owning the bike for about a year, I did my first ever final drive and drive shaft spline lube and I have a few questions. (comments welcome):

1. The final drive splines appear good. Drive shaft have some wear but are useable. There looks to be one area of the drive shaft splines/edge that looks damaged. Someone with more experience, please let me know what you think.
2. I seem to have a pinion seal leak. I have noticed a bit of stain at the final drive/swing arm joint but nothing bad and never any drips or running. From what I have read, I should keep an eye on it and occasionally make sure my final drive oil is topped up.
3. I found debris in the final drive around the splines. Someone said this could be grease that has separated.
4. I also found what looks like a broken piece of a metal ring. Any ideas what this could be?

Thanks for the feedback!



You can see the piece of metal here at 6 o'clock:


Drive shaft splines. They look funny between 11 and 1 o'clock but the rest look good. It also looks like a dent on the edge at 12 o'clock. Anyone seen this before?:

 



Here's the metal piece I pulled out. Any ideas what it could be? It looks to me like a small piece of a metal retaining ring or spring clip...?

[Inge K.]

4. I also found what looks like a broken piece of a metal ring. Any ideas what this could be?

I would guess a piece from a lock circlip inside the uni-joint.....keeps the uni-joint to the g.box output shaft.

[johnny]

greetings chico...

the drive shaft looks like it needs more throttle and the metal piece looks like a screwdriver...


j o

[billday]

I think Inge's saying, pull your drive shaft and give it a good gander.

In fact, if you go to the trouble to pull your final drive, you really should go ALL THE WAY: take off the swing arm and do the clutch splines too.

Seems strange to have splines wear unevenly like that. Don't know if it means anything though.

I too have a leaky pinion seal, and I'm just living with it. But check out the recent thread by the enterprising chap who fabbed the tools needed to replace his pinion seal.

[chico]

Thanks for the thoughts. I saw the recent postings on replacing the pinion seal using some home-made tools and am considering it.

Part of the reason I end up doing piece-meal work like this is I am working on the sidewalk in Brooklyn and can't step away to take a leak without carrying all my tools and stuff inside with me. Since this was the first time getting into it, I was confident I could get this far and get it buttoned up in one go. Now that I've done it, it seems pretty easy to get the swing arm off and get that end cleaned and lubed also. Living in a city makes you do weird things...  :dunno

You think possibly a piece of #3? or less likely, #14?
:du

Thanks again-- this site is such a great resource.

[Scott_]

It most likely isn't part #3. Possibly #14 is what Inge was referring to.
There is a 'locking ring' that is located on the transmission output shaft that the drive shaft yoke slips over the top of the ring. There is a matching retaining groove internal to the drive shaft yoke that fits this ring to help prevent the yoke from slipping off of the shaft splines. This is why when you remove the drive shaft you have to "pop" if off as you have to overcome this ring.

The later paralever drive shafts use 1 of these type clips on each end of the drive shaft as the sliding is done in the middle. Part #3 in this picture is at least a reference.
26 11 1 451 977    SNAP RING - 19,7X2/5MM


Edit:  Ok in your post image part #14 is the same snap ring (same part#)..... they just didn't seem to place in the image in it's proper use or position...............my bad.

[rbm]

If t is the circlip that fastens the drive shaft to the output shaft, wouldn't it be easy to slip off the drive shaft if one tried?  After all, there would be nothing retaining the drive shaft in place.  That could be a test of sorts.

[chico]

I see now and it makes sense looking at the picture. I was tempted to pull on the drive shaft while I was looking at it but wasn't sure if I'd be able to pop it back into place without taking the swing arm off. I moved it around a bit and it didn't just fall out. Would I notice any whackness in how the bike rides if the retaining clip is broken and the drive shaft isn't properly secured in there? Being that its the only k I've ridden, I don't have much to compare it to.

[chico]

Ok, last question (till I have more).

How and exactly where does the clip fit? Is it a press fit on the end of the shaft? I'm thinking of buying a couple clips and tearing into it but I want to make sure I can fit the clip myself before I take everything apart.  (see: the art of sidewalk mechanics above). 

Thanks for answering questions that would be self explanatory if I had a proper work space.

[Scott_]

I don't think I have a picture handy, but there is a grove cut into the output shaft that this ring fits into. It will be a little sloppy(ie clearance) so that when you install the drive shaft yoke the circlip will "close up" a bit to allow the shaft to slide over it, then it will "open back up" when the matching groove cut in the inside of the yoke gets to the circlip. This is how the yoke is held onto the output shaft.

[TimTyler]

This is a K75, right?

... I was tempted to pull on the drive shaft while I was looking at it but wasn't sure if I'd be able to pop it back into place without taking the swing arm off.

Do it. Try to pull the drive shaft out of the swing arm with your hands. It won't hurt anything.

If you succeed it means the snapring is broken. Get a new one for 89 cents, lube both ends of the shaft splines, and pop the shaft with the new snapring back on through the swing arm until it snaps. (Chock the front wheel and push the drive shaft hard until it snaps)

Without the snapring the drive shaft will slide fore and aft on the final drive splines, possibly causing damage to the final drive.

[chico]

Yes, it's a k75. This is just the information I was looking for. Thanks everyone  :2thumbup:

[Scott_]

Ok, here's a picture of the output shaft that the drive shaft connects to.
On the right side/end you can see the notch that the circlip resides in.

[chico]

Quick help needed:
Is the snap ring supposed to be here or forward more on the detention near the end of the output shaft? It started on the outer detention but when I pressed the shaft on, it migrated to here. As it is, the drive shaft won't snap into place.

[TimTyler]

The snap ring should be attached to the drive shaft piece not the gearbox output splines.

When you slip the driveshaft on to the output splines , the ring will snap onto the notch in the splines and keep the driveshaft from sliding fore or aft.

[chico]

I couldn't manage to get it into the drive shaft so I put it onto the output shaft. Now I can't get the f***er off.

[chico]

There must be some kind of snap ring pliers for pinching and spreading the snap ring, right? Screw drivers almost work...

[TimTyler]

Something like this might help http://www.harborfreight.com/catalogsearch/result?q=snap+ring

[chico]

Ok. I got it out. Now I'm stumped on how to get it down into the driveshaft. It was a real tight fit coming off the output shaft and seems equally tight going down through the splines into its seat.

[TimTyler]

I thought it went on the outside of the drive shaft. Not 100% sure though.

[chico]

The old one I fished out and the only snap ring i have seen was seated in the bottom of the input splines at the ujoint end of the drive shaft

[chico]

[chico]

There is a seat at the bottom of the splines. It looks like the ring would go in really easy from the other side but I don't think I can take the ujoint apart.

[chico]

That's what led me to putting it on the output shaft initially thinking that once I slid the drive shaft over it, it would compress and slide into place. Instead, it slid all the way down to the end of the output shaft nearest to the transmission and the drive shaft wouldn't click into place.

[bocutter Ed]

Yeah, it should be in there.