Help figuring out FSM on Knuckle Centering

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Nov 23, 2002
Central Kentucky
I have the Centering tool and measured and got the readings, but hit a snag.
Here are the numbers I got if someone can help explain I would greatly appreciate it.

A= 167.5mm
B= 165.0mm
C= 2.5mm
D= 1.6mm
after this is where I have problems
E should be "D" minus 3mm and this is the lower shim thickness; but this is going the be a negative number so what do I do at this point?
And the upper shim is C-E ; once again a negative would be in there. How is that dealt with?

Any help would be great

something is going wrong whe you scribe the lines . make sure everything fits tight in the bushings ,no slop when you scribe the lines. make sure the tip that scribes the line is sitting tight . if it is sloppy it can give you wrong numbers .sorry on my explanation if it is confusing
you must need shims somewhere because you got a 2.5 mm difference between A and B

a-b =c total thickness of shims needed .which you measured at 2.5 mm
My measurements had mine at 2.73mm of shims required.

I did triple check that the bearings are seated all the way. They are installed correctly.

I'm attempting to install mini truck disc knuckles on my 1980 HJ45 that had drums.

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