I am preparing to install gear driven Cams in my 2003 Road King. I am told that I need to check my crank run out.

1. What is crank run out?

2. How is it measured?

3. What is condsidered unacceptable?

4. How is excessive run out corrected?

 

Crank runout is typically checked at the end of the pinion shaft with out the cam plate with a dial indicator and is said by the factory to have a limit of .010". Andrews gear drive instructions call for checking it with the cam platewith a tolerance of .003". When we use the billet R&R cam plates we can get away with .006" checked without the cam plate installed and don't need to check it with because of the tighter tolerance shaft to bushing.I correct excessive runout by truing and welding the crank assembly.

 

Randy in a later built bike it now seems like those that do as you posted are now stepping away from doingthis and going with an S&S setup or other aftermarket cranks?Is it a sticking your reputation on the line thing or is there other things playing into this?

 

We have a lot of cranks come through here that just get the true and weld and these work ok for moderate builds. For the 120 up range we either send them to Hobans for now or use the S&S and weld them. A lot of people are now using the R&R billet cam plates which really do stabilize the lower end.

 

Randy, you are right on the money, although I went with a Jims crank and had Hoban's (Darkhorse) work their magic on it and the cases for my 120" build. I dont work at a dealer, but I live doors down frommy dealer's service manager and they are having issues with both stockers and builds scissoring the cranks. I am also installing a billet cam plate. Randy, I heard through the grapevine that now HD is accepting .012 as acceptable cause so many have gotten to the .010. (Just wonder if they are trying to outlast the warranty period...hmmmm)

RKK, the only way to fix an out of spec crank is to remove it, true it, weld or pin it. Once you get to the point of splitting the cases, I would scrap it and at a minimum go with the stronger SE crank, a JIM's or S&S, and oh, BTW, you might as well stroke it!

 

Thanks guys, however I am still trying to understand HOW to determine if I have crank run out that is out of tolerance. I am very comfortable with my ability to install the gear driven camshaft set, however I am uncomfortable with all of this stuff that I am hearing about Run out. I hate to take it to the dealer for this.

 

The pinion end of the crank is what you measure with a dial indicator. Set the indicator up so that it reads on the side of the pinion at an angle of 90 from the crank. Zero it and rotate the crank. You may get readings both plus and minus, for example you may get .002 plus and .002 minus and you add those together for a total of .004 runout. I had an 03 RKC and had no issue with the crank of my 95" build. Put close to 40k miles on it after the build and it still ran great. Ran Woods TW5G cams and gear drive.

 

Dalton: Why go the +/- route. Just set the indicator to zero on either the high or low point and get the .004 total reading. By the way, yes .012 is the max now. Figures becauseI have .007 on the sprocket shaft. I'm hoping the pinion side is within at least .003. Not going to check, screw it. If my oil pressure goes south I'll know the pinion bushing has been beat out from excessive runout, and then I'll look.
Ron

 

Why the + and - route...cause I am too damn lazy to reset the indicator is all

Yep, oil pressure goes south, Houston, we have a problem.

 

[sm=itsok.gif] I do the same thing.
Ron