Shear agony: countershafted

[Darrell]

This happened on my 250SL at the end of a great ride:

The sprocket did a nice job of machining the new groove on the counter shaft. The sprocket came through the ordeal none the worse for wear, and this is the first time I've ever seen this type of breakdown.

Anyhow, I'm thinking of trying something dumb, which is to weld the sprocket to the countershaft and ride it as-is until I have the time and motivation to split the cases on this motor again.

Has anybody else been this route before? If so, I can be persuaded to fix this the right way... if I might be creating more headaches for myself....I guess

Thanks

[Bullfrog]

That's some mighty fine selfie-machining! (Sorry. All I've got for this situation is semi-funny quips . . . and NO experience with this sort of thing.)
Ed
PS: . . . and a propensity for recommending a new countershaft and a countershaft sprocket with slightly softer splines. Um, no, I don't know how to find/identify/specify softer countershaft sprocket splines.

[Bill2001]

Wow. That is sooo strange-- i've never seen splines worn this quickly or this perfectly. That output shaft must have had a harness of butter!!

[racerclam]

Most likely the failure was caused by the sprocket nut not being tight enough causing it to work the splines the same way that a hodie can take the splines of a clutch hub from being lose .
Rich

[viclioce]

Yikes! That's one I haven't seen before! I'm with Rich. Guessing your sprocket but came loose and allowed the sprocket to spin on the output shaft. Did you have a functional lick washer under the sprocket? Folks tend to over use those and as they wear out they don't hold the nut like they should. ; D Victor

[Bill2001]

I can see it wearing over several years, but the engine was assembled 500 miles ago and that impresses me as rapid wear.

[viclioce]

It doesn't take long when you consider how fast the control shaft is spinning with that sprocket on it. And, the sprocket turns with the rear wheel via the chain, even if coasting in neutral or rolling the bike with the engine off. Also, even if you had grease under the shifter cover, there's not an excessive amount of grease at that junction. ; D Victor

[bchappy]

Welding the sprocket to the counter shaft may leave you with one problem. Usually if the sprocket nut is not tight oil will come out between the sprocket and the collar behind it. If you weld the sprocket to the shaft there is no way to tighten it against the collar so therefore an oil leak that may sling all over the case. There is also an O ring inside the shaft that will probably melt. You could try it and split the case as a last resort.

[michael_perrett]

Cracked Toad cylinder, countershaft splines gone, what is happening to the world. I would try welding, just to see how it holds up, but would only ride uphill from the house.

Mike Perrett

[thrownchain]

If you're gonna fix it, do it right, no real excuse not to.

[Bill2001]

Or, as I've heard "do it slow or do it fast, just don't do it half-assed".

[bchappy]

To quote Harry Taylor "If you don't have time to do it right, will you have time to do it over?"

[viclioce]

I would just replace the entire control shaft assembly. It means splitting the cases. What kind of shape are your seals & bearings in? Did you replace them when you did the build 500 miles ago? If you replace it, they have the newer control shaft assembly at Strictly Hodaka which is supposed to be super! ; D Victor

[Darrell]

Cracked Toad cylinder, countershaft splines gone, what is happening to the world. I would try welding, just to see how it holds up, but would only ride uphill from the house.

Mike Perrett

Maybe the metallurgy has gone past the "Best Before" date?

[Darrell]

Thanks everyone for the brainstorming on this breakdown.

It's my practice to tighten the sprocket nut with an impact wrench. I try not to use all of its power thought and sort of let it coast into the until I get a couple of rattles.

The tab on the lock washer was folded up as it should be and the lock washer didn't shear off with the countershaft.

Nobody's given me much encouragement to do some haywire repair/mechanicking so I'll skip that and do a teardown. I'm just a bit bent out of shape because there's no other value to be added to the process because all the other internals are fresh and/or in good condition.

However, since the Trail Whale beached itself the Wombat started running strong for a change and I had a good ride with it yesterday; no fouled plugs and running strong.

I've come to understand that like cats, you don't own Hodakas, they own you. And they act like they share the same tempermental DNA as Chitty Chitty Bang Bang and Herbie the Love Bug.

Here's the Wombat showing the whippersnappers the way to the old cabin in the woods yesterday:

[viclioce]

"I've come to understand that like cats, you don't own Hodakas, they own you. And they act like they share the same tempermental DNA as Chitty Chitty Bang Bang and Herbie the Love Bug."

Now that's a comparison that scares me!!! Good luck with the redo! ; D Victor