The Stovebolt Site Forums The Shop Area General Truck Talk King Pins. Standard or Oversize?

I measure my axle bores from 0.919-0.923" (cheap micrometer). The standard size kingpin is 0.921".

Is that the one for me? Do I see if it fits by hand with no wobble?

Thanks, guys!!!

My '38 has bushings that are sized to the kingpins by reaming.

You use oversize kingpins if the eyes in the axle are wobbled out or out of round. Standard kingpins will work so long as the bushings are not worn through. As Tiny points out, the bushings are reamed to fit after installation due to the any issues with the bronze being slightly out of shape from being pushed into the bores.

Jeff

I'm getting the kit w/pins, bushings, etc. Would it be safest to get the 0.010" oversize and ream the axle?

Unless your current bushings are worn to the point that the axles are oblonged you're wasting your money IMHO. I'm not an expert by any means. Find a shop that works on big truck springs & axles and ask them. They do kingpins every day.

Tiny is absolutely right. He is affirming the adage, "if it ain't broke, don't fix it".

The bushings were worn thin and the holes to accept grease were not even lined up with the zerks! No wonder I couldn't get grease to the kingpins for the last 20 years!!

I think I'll get the 0.010" oversize and bring the stuff to the big truck shop that used 30,000 lbs to get the old pins out in the first place.

Thanks, guys.

Two things seem to be getting mixed up here. Worn bushing don't produce worn axle holes. Oversize kingpins are used to correct worn axle holes.

The bushings are in your spindles. When you buy the oversize king pin set, you aren't getting larger bronze bushings! You are getting a slightly large diameter king pin! That means you have to ream out the AXLE, not the spindles or bushings. So unless the hole that the king pin is mounted in in the AXLE is worn out, there is no need for oversize king pins. If your spindles are worn out they can either be replaced or you can bore them and have oversize bushings made and inserted.

There is an interesting situation here. I have not yet heard of any shop offering to bore spindles out and install oversized bushings. However with the other problem with the axle, I think it is common to have the axle bored out and hardened steel inserts installed to bring it back to standard. I am guessing that repairing the spindles is a no no in the industry, maybe because of a lack of excess metal around the area of the spindle bores.

The axle holes in my '41 were out of round even though the bushings were not badly worn. I used an adjustable reamer that was longer by several inches than the axle ends and brought the holes out to .010 oversize. .010 didn't quite get all of the wear out, but I would say it got 95%, so the new kingpins made nearly full contact except for a dime sized area at the bottom edge of the hole. AFTER I did this I had the axle shop straighten the axle and bring it back to spec. I knew that the truck had been in a wreck in 1941 just before my Great Uncle bought it in 1942. Frame was OK but the spring hanger was tweaked such that the passenger side spring didn't line up in the front by about a 1/2". I bought new top leaves for the front spring packs because the bushing hole in the spring eyes were badly worn. On the advice of the spring shop, I put the new top leaf in and heated it up at the rear, red hot and bent it slightly so it lined up in the front. I then sent it back to the spring shop and they re heat treated and tempered it to spec. Every thing lines up fine. The alternative would have been to unrivet the rear hanger and try to straighten it and re attach. Seemed like way more potential for breaking or damaging the hanger than just tweaking the spring a bit.

Sid Drapel in Guthrie Oklahoma has a drop axle shop and he bores the spindles out slightly and makes new over sized bronze bushings.

Sorry for my confusion. I misread the shop manual. I thought they were reaming the spindle itself but it was the bushing in the spindle that got reamed. They show bushing reaming tools for standard, 0.010 and 0.20 oversize.

I'm going to buy a standard size kit since one of the thrust bearings is cracked. I'll then punt and bring it to my favorite big truck shop.

Thanks, guys!