Trying to save a bargain K75S and learn something along the way

[The Mighty Gryphon]

No noise when the trans is spinning, but when you pull the clutch things get a bit noisy?  I'm going to guess your trans is ok and that something is loose or missing in the clutch. 

Keep an eye out for stuff that may fall out when the trans is separated from the engine.

[Sit]

Think I found the problem.

[Laitch]

Smooooth!

[Martin]

 :yow How's the shaft.

[Sit]

Shaft actually looks good I think.

[Martin]

Could be an optical illusion but the lands on top of the splines close into the housing look thin.
Regards Martin.

[Laitch]

A straight-on shot should tell the story but they don't look too bad from here. I think the photo's angle may be distorting their appearance.

[DavidATL]

Whoa. That's weird looking - looks like uneven wear front to rear. Is there an alignment problem?

[Laitch]

Whoa. That's weird looking. Is there an alignment problem?

I've stared at it enough now that it's starting to act like one of those portraits where the subject's eyes follow me around the room.

Are the locating dowels still installed in the intermediate housing, Sit?

[TrueAce]

The spline have a diminishing taper from bottom up to case.......they are wider on both ends but look ground down as you get about 50-75 % up. Need more pics.

[Sit]

Not sure what happened to the photo to make it look like that. Yes some of the splines to taper a bit in the middle.

[TrueAce]

More pictures...... :dunno

[Sit]

Will get a new clutch ordered up.  Not sure about the input? Shaft.

On a minor up note, found an extra key for the bike in the belly pan.

[F14CRAZY]

The driveshaft splines looked pretty bad but I think the final no-go were the clutch splines. I myself replaced my clutch disc because the splines in the hub were looking close to failure. I don't think I've read of a case where the trans input splines got bad enough to fail. Same for the trans end of the driveshaft...wear is most all with the final drive and that end of the driveshaft

[Sit]

So I am ordering up a new clutch pack being the spring, pressure plate, clutch and housing cover along with the tid bits to put it all in.  I see in the manual it talks about a tool to keep things from moving and I see that it mentions everything is balanced at some point and to mark things.  I know I will be tossing everything that comes out.  So is there anything I should be marking up before taking off the cover and starting to remove things?

[Laitch]

So is there anything I should be marking up before taking off the cover and starting to remove things?

No, not if you are installing a new clutch pack. The Clymer manual explain the clutch pack marks. As a balanced assembly, each of those new parts has a balance mark on it and when assembled the marks should be spaced at 120º. A clutch alignment tool helps keep the parts in alignment as the clutch plate is tightened. It's good practice to replace the main seal, the o-ring, the clutch nut, the clutch plate bolts and washers, and the clutch rod boot when dealing with a bike that's had sketchy maintenance history.

It helps if you put your general location in your profile so readers can direct you to sources for parts or information. You should have viewed the Chris Harris clutch spline lube video by now.

[Sit]

Thanks.  Yup, have all of that stuff on order except the main seal.  Will look into doing that.  I will try to watch the video before I get further into it.  If it is the one I was watching before, the camera moves so much  it gave me a headache something fierce. 

[Martin]

Once you have the new clutch disc I would be trying it on the shaft to see how much rotational slop is visible. Try it where it appears to be worn the most and where it is worn the least. If a lot of movement is visible you might look into a secondhand gearbox, I believe they can be had in the US for around $200.00.
Regards Martin.

[Sit]

So is oil up inside here ok?  The bell housing was dry when I began removing clutch but when I pulled the clutch housing off and took the o ring off, a little bit of oil showed its self coming from inside.

[stokester]

Great looking bike, I hope the drive train issue(s) get sorted out.

Is that a Corbin seat?

Got one like it on my RT.

[Vespa no more]

Someone somewhere ... probably nearer than you will know (until you've actually got the replacement) has the parts in their garage.
I'm suspecting K bike owners just love to squirrel away important pieces for that time they'll need them.
But because they know they are valuable, they keep the maintenance up to the parts - eg spline lubes and they never end up using them.

Parted out the bike might be worth $1500 ... but you wont do that of course.
You've got the fever and there's no return.

[Laitch]

So is oil up inside here ok?

Oil should stay in the crankcase where it belongs rather that being flung around clutch parts. If oil leaked when you removed the o-ring, replacing it should end that. What did you use to remove it? Are you following your manual's instructions?

[Sit]

Oil was behind the clutch housing. As the housing came forward and the o ring removed the oil came out of the area of the bearing. Just a tricklle. I think it is ok. Replacing the main for insurance.

[Sit]

No test ride yet, but everything is buttoned back up.  Bike starts and shifts through the gears on the center stand with no drama.  Still need to get the belly pan on, it is presenting the most trouble of the entire rebuild so far.    Once that is on, I will test ride it and see how she does.  So far in parts and tools, less than the cost of the bike, $510.  Total expenses so far, including bike - $1,060.

[Laitch]

No test ride yet, but everything is buttoned back up. 

Congratulations on getting it together.  :clap:  It might be instructive for others if you summarize what you did—including the costs—and post a picture of the bike in its new state of vigor.