I already know that welding on cast iron has many problems associated with it - cracking in the parent material being the biggest one.  I am really leaning toward the viability of making replacement parts from a stronger material.  The biggest hurdle on this approach will be the cost.  Not just the raw material, but the milling process as well.  With the double D hole shape the tight corners become a concern while milling.

I am thinking that soldering the existing parts will not increase the strength enough to prevent the part failure.  Yes, it will close the gaps in the part fitment, but it will also create assembly issues when trying to put it all back together.  This also applies to a weld approach.  Once the shaft and pawl are one piece, you may not be able to get them back in.  Again, this leads me to think that improving the strength of the material used will be the most viable solution.  What the associated costs will be is yet to be determined.  How much money is it worth to solve this issue?  How much would you spend to prevent this failure mode?  Hey, wait!  I thought I retired from this type of work!  

More info please.  

These washers you installed, have any pics?  

If no pics, what can you tell us about the washers?

Lowe's flat washers, I took dial calipers and shopped for washers within thousandths of each other, I don't remember if more than one went under a spring.
It didn't take long before the sintered part splintered.
They were the most common flat washers on the shelf. Not extra thin or thick and the other dimensions are nothing odd.
I didn't have a slippage problem, not bad,,without the washer s. With them, certainly not.
Full disclosure, that was around twelve years ago, because it was my first S.I.L. who destroyed things who was riding it when it broke. It ruined thelongplastic coated chain tensioner that mounts to the actual cam chain tensioner. Sorry if that is confusing.

The washers might solve your problem, but you and everyone else who has been in there knows that sintered metal part is the weak link. Unlike a clutch cable issue, the busted throwout isn't something you want to ride with without first Looking behind the clutch cover and knowing a buncha stuff UpInYonna isn't busted and gonna create problems .
Some brave and industrious individual otta carefully study it and see how hard it would be to whittle some out of what? Mild steel? Been years since I was in there. I don't remember how they are built, but I Do remember it looked like a real hassle to machine That shape.
Would casting be a better answer?

As with all mechanical failures, once you strengthen the weak link, the stresses are applied to the next weakest link.  My negativity is showing...  we could end up gaining enough strength to break the case.  Being cast aluminum I am a bit worried about the pivot point of the shaft.

Justin, the intent of my inquiry was to try and determine if there was any chance your washers put the springs into coil bind.  That's why I'm curious about thickness and location.

After observing how the springs behave on the spring tester, I am of the opinion that the fractures were related to limited travel rather than spring force.  It's also possible that it was geometry.  As mentioned earlier in this post, get the pushrod too long or too short and you get into "bending" mode rather than "pushing" mode.  I don't see a need for solder, the shim tightens the thing right up and it stays tight.  It's also simple to make and install.

I guess I'm gonna find out about the springs.  I'm either gonna use the Barnetts or the DR650s.  The Barnetts don't impress me much.  They lost about 10% of their force after only a few months of service.  The stockers don't lose anything, but their spring rate is too low.

If you watch one of these springs on the tester you get a good idea of why I'm concerned about coil bind.  As you compress the spring, the load goes up in gradual increments, nice and smooth.  It plots out in a straight line, right until coil bind.  Then, the slightest bit more compression and the load goes straight up, like from 70 lbs to 100 lbs in only .005" to .010" movement (maybe less).  That sucker's solid.

I finally met with my machine shop to go over this part failure.  Very encouraging meeting.  Not only is he the owner of this manufacturing facility, but he is also a metallurgist.  He is recommending using a solid piece of material, laser cut to shape, blanchard ground to thickness, and mill the push rod cup into it.  He is recommending using AR500 steel for this application.  He can hold a .001" tolerance between the flats in the double D hole that the shaft fits into.

So here is the deal.  At today's price check through Partzilla, this piece is being sold for just under $10.  I can get a batch of 25 pieces made, but the selling cost would end up around $20 each plus shipping.  How many of you guys would be interested in buying a part that won't fail for twice the cost of the original?  Testing could be done to prove the part strength, but it would come at the expense of a shaft and an original part.  A set up could be made using a torque wrench to find out how many ft lbs it would take to cause the original part to fail.  Then duplicate the test on the new material part.  This would solve both the stock clutch failure mode, and allow those who want to beef up their clutch to do it without breaking parts.  Trying to make just one for myself is not at all cost effective, it would cost me a lot more to do just one.  Let's see if there is enough interest to get this idea off the ground!  

I already have a spare shaft and actuator pawl, so I can list the breaking torque of the original part, and what torque it takes to break a new one.  I just need enough people to be willing to buy them to get the first run made.

Justin, the intent of my inquiry was to try and determine if there was any chance your washers put the springs into coil bind.  


I'm sure they were not. I'm just not the guy who would do that. Good point to consider, just, no, not me.

There is a ninety degree, inside corner, that is loaded during a shift change. Doing tests to prove a steel billet made, turned part is stronger than the sintered part seems silly. People who want one can get one or don't. It's not worth the cost of proving it.

For the record - I am not trying to go into business on this, nor am I trying to make a large profit.  I am trying to improve a part that is known to fail, that will be a detriment to my own project bike.  If I can help others who like this bike?  All the better.  I am retired, and intend to do so.  Not worth it?