83 440 LTD Belt - Output shaft moves end-to-end.

A few weeks ago, I was riding with my wife, and as we pulled up to a stop light, the bike went 'clunk' and we didn't have power to the wheel.
Initially I thought primary chain, since the bike runs, and just doesn't have power, but when I pulled the clutch cover, everything was fine on that side of the engine.

Then I pulled the left rear cover (of course I took the time to pull the clutch cover first...) and the output sprocket - part # 13144-1065 basically fell of the bike. The inner splines are eaten out, so part needs replacing. Luckily, the output shaft is a harder metal and I see no sign of damage on it. the nut was in the cover, but the washer was nowhere to be seen.

After cleaning up I noticed that the output shaft can be moved end-to-end a short distance (I estimate total movement around or slightly less than 1mm along the length of the shaft). Is that normal, or do I need to bust open the transmission and replace bearings before I replace the output sprocket?

So the sprocket hogged out? I'd start with a new one and tighten it down to see if the play goes away.
Steve

Allright, I've got a new drive cog on the way (new clutch cover gasket too).

I do think I'll do a complete overhaul on the bike in the future, just hoping to fore-stall that for a couple of years.
Here's hoping that with the new drive cog, there's no movement in the output shaft.

How would installing a new pulley tighten up a loose shaft?
If the shaft moves fire and aft, the bearing may be shot.,
If the shaft moves in and out of the case, there may be a worn thrust washer.
Does the service manual list an acceptable measurement?

I think the idea was to see if it tightened the shaft without a promise of a new sprocket fixing it the way I read swest's response....

The term cog is confusing. Pics would help. If the sprocket splines are shot and the nut came off, the washer missing, there could be slight in/out play in the shaft. Clutch cover gasket? :huh:
Steve

Yes Swest, we all seem to be using different terms.
As I understand the conversation, the front sprocket has lost all of its splines and is no longer useable, but the splines on the output shaft seem ok. Also, the OP noticed some play in the output shaft. He also took off the clutch cover to see if there was a problem there, hense the need for a new gasket.
Hopefully the OP will set us straight.

I try to discourage hopping around. If he took off the clutch basket cover, he just cost himself money. Pics are always the best way to determine we are all on the same page like the one with the hole in the cases that turned out to be in the tranny cover. He's new so I give him a pass one his terms. Gotta start somewhere. :whistle:
Steve

Yup, systematic diagnosis is almost always faster and cheaper. That's probably why the factory boys dedicated so much space in the fsm to it.

TexasKZ wrote: Yes Swest, we all seem to be using different terms.
As I understand the conversation, the front sprocket has lost all of its splines and is no longer useable, but the splines on the output shaft seem ok. Also, the OP noticed some play in the output shaft. He also took off the clutch cover to see if there was a problem there, hense the need for a new gasket.
Hopefully the OP will set us straight.

That's pretty much it. I took off the clutch side looking for the problem, it wasn't there, now I have an opportunity to spec the clutch and buy a new gasket. For the sake of my actual question, forget I ever said 'clutch' or 'gasket'. That's just a distraction at this point.

I can upload pics on Sunday as I'm not in for the evening and won't have garage time tomorrow.

As for the movement, If it was fore-to-aft I wouldn't have to ask. The movement IS 'in and out'.

As for wear limits. The only wear limit listed that I'm not entirely clear on is shaft-to-bushing clearance. That sounds like a radial measure to me.

There is a collar between the output sprocket and the bearing, so tightening down the output sprocket could very well push that collar into the inner bearing race, securing the shaft (eliminating the end-to-end movement).

That's what I was thinking. Tightening down the sprocket sets pre load on the bearing inner race not the whole bearing. If you put on a new one and the play goes away, you've got it.
Steve

I'm posting 3 pictures:

1. The 'hogged out' sprocket (I'm sorry for referring to it as a cog earlier, that's just how it was listed on eBay, funny thing, the "drive cog" cost about 1/3 as much as the "output sprocket" even though they were the same parts in similar condition, a little flexibility in part searches can be funny like that).
2. The output shaft (i.e. secondary shaft of the transmission). As you can see, the splines are in good condition. I have not cleaned up the area and you can see the greasy residue that makes me think that it would be a good idea to swap out seals at some point
3. The clutch with cover off. If you are attempting to address my question, please forget you saw this.

The scraping marks you see on the output sprocket are from rubbing on the cover while coming loose. No need for further root cause analysis there.