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Measuring kingpins and bushings

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big6

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When measuring kingpins and bushings for wear, what are the maximum and minimum tolerances allowed? I cannot find the dimensions in the service manuals that I have. The simple instructions are to replace the bushings and ream using the fixed piloted reamers. I would assume .002 to .004 inch??? Lower pin bushing surface measures .810 inch and upper pin bushing surface measures .685 inch with no out-of-round or tapered surfaces measured. Any help is appreciated.
 
My shop manual gives top diameter .68625" to .68675", bottom pin diameter of .81125" to .81175", & a clearance of .00075" to .00175".
D
 
Thanks Dave… I probably have made the pin dimension a little smaller in the process of cleaning and polishing the surfaces. I don’t believe I have removed enough material to make a difference since you size the bushing to fit the pin.
 
Big6, Just curious here. "Since you size the bushing to fit the pin"-How is this accomplished if You are using a "Fixed" piloted reamer.---Keoke???
 
I will not be using a fixed piloted ream... I will use an adjustable ream and a pilot that I machined...
 
Hi again,
You didn't ask, but the Oilite thrust washer at the top originally used adjustable thickness steel washers on each side of it to set end float, which should be set to .002" max.
D
 
Dave, thanks again for your help. My manuals are fairly clear about shimming the end float… They just didn’t cover bushing tolerances.
 
big6,im wondering,did you require the use of a press to remove/replace the bushes?thanks anthony7777 1963 bj7 3000 M.K.II /ubbthreads/images/graemlins/hammer.gif
 
7777, If you have access to a press that makes it easy.They may be drifted out just a bit harder or if you are very careful they can be cut and folded up on them selves and extracted. On the otherhand, Virginia T can probably get them out for you quick as a /ubbthreads/images/graemlins/wink.gif. However, I made up a set of tools that will remove the bushes and reinstall them correctly.---Keoke- /ubbthreads/images/graemlins/driving.gif
 
keoke,i went to a couple places [experts]as they call themselves,and was told they must be removed and installed with a press,bull,when i did mine id done exactly what you described and it worked realy well,i cut a shaft about 15" long out of brass on my lathe and used it as a drift,i dont know, perhaps some are realy stuck in there,but i cant see how with a little work you couldnt do it without a press.the book says you can remove them by hand. /ubbthreads/images/graemlins/yesnod.gif
 
I recently redid my king pin bushings. I found that the upper busings had no perceptable wear, so i only had to do the lower bushings. I guess this is because the lower bushings have the greatest forces on them. I happend to have a set of bushing drivers that I used to get the bushings out and replace them. You could probably get a set at Harbor Freight or an auto parts store. I also happened to have an adjustible reamer that fit the lower bushing. The reamer was about 12 inches long so I put it on a lathe and turned one end down so that it fit into the upper bushing. With and adjustible reamer you have to be very careful not to over-ream or you will ruin the bushing. I found out this the hard way, at ten bucks apiece you don't want to do this.
 
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