King pin steel grade

D

DocJohn

Member
I was wondering if anyone knew what grade of steel the Ford king pins are made from.
I'm struggling to get new king pins for the Pilot Woodie; in my NOS set one is cracked, and in the aftermarket set the cotter pin notch is too wide and in the wrong place and I don't like the way the thrust loads go through a welded on washer.
So, I'm thinking of have some made. In the absence of any other information I'll probably specify AISI 4340 and get them surface hardened. Any views?
 
I use a carburising steel, ie Impacto, Super Impacto, EN39B, EN36A. Machine them up leaving o/d say .012" over the finish size. Get them carburised around .035-045" case and grind to final size. When I turn them in the lathe, I leave a protrusion above the head. This enables me to fix the driving dog for the final grinding operation between centres. Afterward, simply cut the protrusion off with an abrasive cut off wheel
Commonly available 32-36 Ford V8 kingpins will fit, but you may need to grind off a portion of the head as they are to accommodate the mechanical braking system. The cotter grooves are in the correct locate.
 
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Thanks Brian, that's very helpful.
I was so disappointed in the aftermarket ones - there's about 1/16" axial float due to the oversize cotter pin notch - that I'd rather have some made to my standards.
Regards, John
 
John, Before you go to that expense, please investigate 32-36 king pins. Buy some NOS gennie Ford ones, you can be assured they'll fit right. Just need to trim the heads.
Those aftermarket ones you've obviously got experience with are poorly made. The originals do not use a washer for a head!
 
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