Measurements please

[John Nickell]

Does anyone have the outer diameter of the king pin bushing that goes into the brake spindle (or the inner diameter of the spindle), height of the bushing, and the diameter of a new king pin? I was looking at SSBC’s “Royal” king pin kits that use needle bearings instead of brass bushings but of course are not available for our cars, I was wondering if anyone has researched this before and what they found. I know a of you subscribe to don’t fix if not broken policy, but this seems like a worth while endeavor to me.

Sorry maybe I should mention that this is for a ‘48 dodge D24

[RHDSP15C]

From memory the diameter is 49/64. My car was fitted with these needle roller

bearings - I think they were Torrington B15. I will take a look when I next visit where my car is stored. I was unable initially to find these bearings as Torrington informed me they were last made 45 years ago. Also to make things worse they were used only on the Canadian and Australian cars. I got to the stage where the only way out was to machine a bronze bush to the same dimensions as the needle roller but I got lucky and found a set on ebay Canada.

[RHDSP15C]

I looked up the Chrysler Corp Export Division engineering orders dated November

1948 for the D24. First production used bronze bushes upper and lower with a king pin .7955 diameter. After approx one year a design change was made and the top bushing was changed to a needle roller Torrington NB-15 OH, Chrysler

part#681378. .7955 ID X 1.0013 OD X 1.005 L. Reason for change was stated as "premature failure of upper Bushing". Sometime later another change was made replacing the lower bushing with the same needle roller, I couldn't find an explanation for the second change but I can guess why. I the checked the Canadian paperwork and it appears they used the needle roller on top and the bush on the bottom for all their cars right thru the series. The Chrysler pilot reamer is marked .797. Also the core plugs need to be 1/16 larger in Diameter.

To make this change you would need to linebore your spindles to suit the needle

bearing. When pressing these bearings into the spindles it is necessary to ensure the lube holes line up with the Zerk fittings.

My experience is that the needle roller set up was vital for cars running on rough roads and that usually means dust. With the dust and without frequent

greasing the needles chewed the kings pins quicker than the bushes hammered out. I checked ebay and I found the king pin kits with these bearings are still out there.

[John Nickell]

Are the upper and lower king pin bosses on the spindles the same size? I took the spindles off and the inner diameter of the upper boss is larger than the lower boss. It appears a previous owner had attempted to sleeve the upper bosses to take up the size difference between the boss and the bushing. I was just wondering if the size difference is correct and the king pin set should come with larger bushings for the upper bosses or if the upper bosses had been stretched and the previous owner had attempted to fix this?

[RHDSP15C]

Answer to first part of question - no. The hole in the top should be 1.0013 and the bottom .925.

[John Nickell]

Is this size difference true for all ‘48 dodges or just for the foreign models that used a bushing in the top boss?

[RHDSP15C]

There were three king pin service packages available for the D24.

933 435 upper and lower bronze bushes

1243 731 upper and lower needle rollers

947 557 upper needle roller lower bronze bush

I have the serial number cut of points where the different combinations occurred

but where those cars went is another matter. If you let me have your serial #

I can tell you what my book says. I would figure you need the 947 557 package and that your serial # is between 31006517 and 31057047 or between 45022935

and 45029117.