If the pin fit is improper, then sure, welding will help. Maybe lot of stock Harley pins have a loose fit.

If the pin fit is correct, and the material is inferior (not meaning bad quality but lower strength), the best weld in the world will not improve the strength as compared to a proper fit, higher strength pin/flywheel. One benefit of higher strength materials is that they support more interference (between the pin and the flywheel) which sustains more torque before slipping. Furthermore, with tighter tolerance control, higher nominal interference can be used without fear of exceeding the yield strength. This further would increase the torque that the pin could take before slipping.

 

OK, so why would that make a difference unless there is something seriously wrong with the case. I guess that the machine shop can pull the crank & put it in some calibrated v-blocks but how many shops do that?

 

TIR is Total Indicator Reading..... from min to max. Actual runout is the distance from the nominal to the min or max.

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So actual runout is theoretical? Otherwise how do you establish a datum for your zero nominal condition? CMM?

 

I disagree-

I can and most welders could weld that so something else will fail, not the weld.
Yes the original steel is probably crap- if the interference is correct the failure should be with the original material.
Not the press.
That said, an interference fit is only as good as the parts and , machining involved.
I was told the HD wheels (crank) are now made offshore, which would explain a lot.

 

I was in a bit of a hurry... sorry if I gave a misleading definition.

Runout basically is at any point along the feature, independent of any other point. TIR is at ALL points along the feature, inclusive. If you picture a crank that has shifted, AND the output section is bent.... runout will be less than TIR as the latter is from the lowest low to the highest high along the entire distance.

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As I said before if the crank is in good overall condition I would pin and weld this is not the same as just a surface weld.

TIR total indicated run out. So if the needle swings .020" the actual run out is .010"

Also I certainly know the difference between a multi piece ball bearing crank and a Harley single pin crank....Just put the GS1000 experience in the post as a caveat as to the pain I went thru.

 

Most set the needle on 0 at the low point. Then, if it goes to .020 on a .001 increment indicator, then it is .020. But even if you did not do that, it is still .020, just a little more thought would need to go into what you are seeing. It's is possible to get a .020 indicator travel and not be .020 total but only if the shaft you are indicating is bent which I would not think this is the case here. When the two large flywheels turn on the center pin, it basically moves the cam sprocket shaft and the opposite side primary sprocket shaft off from the same centerline.
That much would surely put a bind on the crank bearings if it was scissored.

Keep in mind, a straight true shaft in a close tolerance bearing like a ball bearing when turned will always be true. A TC crank is pressed together. The sprockets drive is very tolerant of runout. .012 hurts nothing out on the end and that is the manual spec..020 would be OK if it was just the cam sprocket shaft

 

Well that means that you need to V out location of the weld and fill. Unfortunately no one does it. The pin is hardened and would be hard on tooling (even carbide). It you did you'd still likely have issues as when welding, the press fit relaxes. The best way to tighten the fit is with a steel plug on the ID of the pin and use the best materials you can get for the wheels. Or use a forged one piece crank.