The Stovebolt Site Forums The Shop Area Driveline Upper kingpin thrust clearance

I just had new kingpin bushings installed and reamed at a local machine shop. Nice job with just a push fit on the pin. I have a 3/4 ton 54 chevy. In the kit comes the bottom bearing consisting of 5 pieces. I have not found what the upper clearance should be in relation to the axel. The shop manual doesn't show a shim there. I have .013" on the pass. side and .018" on the drivers side. All the weight is carried on the lower bearing so do you need a shim on top? Id like to assemble the truck this weekend but if I need to order kingpin shims I guess its up to you alls answers.
Thanks Sharon

Sharon,

Grigg is a good source of information. Here is a write-up by Grigg.

"6.5 test fit your spindle and the thrust bearing over the axle, fit any shims necessary to take up the gap on the top side of the axle. Don't pound and wedge it together but also don't leave any gap a shim will fit in. (in my case no shims were necessary but before it would fit together nice and snug I had to remove the burs and wear ridges as previously mentioned.)"

Here is an excellent "Tech Tip" on king pin replacement, by Randy Baumann.

** I think most shoot for a clearance of .005 or less. **

Very nice article. I will find a shim kit and take up all the slack.
Thanks Tim

Sharon,

My 1954 3100 u-joint kits (different brands) all came with a few shims. You might want to check with the machine shop (but, if there were shims, they are probably long gone).

For example:
https://www.chevsofthe40s.com/detail/6372/Chevrolet_Kingpins_34ton_1ton_112ton_Except_DD.html

I do not know sizes/diameters, but here is a kit of shims:

That was the one I was going to order, thanks Tim