Help identifying straight ball arm and 1 1/4 inch ball arm caps

[anothercarguy]

Could someone help me identify the arm in the photo below. It is the length of a Pitman arm and has the same keyway notch but the unknown arm is straight whereas a pitman arm is angled at about a 45 degree angle. Anyone know what this straight arm fits?

The ball is 1" round but shows wear, measuring 0.944 and 0.90" in diameter. I guess this is what they call football shaped. Is the ball arm still usable or is it worn too far and junk?

I also have two ball caps that fit a ball that would be about 1 1/4" round, but the two caps are different heights. I think both are New Old stock because they have numbers cast on the top of the cap and show the original machine marks inside the cup.

Any help with the ID of these parts would be appreciated.

Thanks,
John

Edited for emphasis and clarity.
This first photo shows a 45 degree angle of NOS Pitman arm on the Left and the unknown black, straight arm on the right that I am trying to identify.

Pitman arm on Left-Unknown arm on right.JPG (66.76 KiB) Viewed 617 times

[speedytinc]

Ball on the arm is way to far worn. It can be built back up by wire welding & carefully reground to 1.00" & reused.

[Allan]

The thinner 1.25" cap may well have been filed down as it and the ball it worked on were worn. Filing closes down the gap enabling continued use. That one looks just about past being useful any more

New pitman arms have been reproduced, so getting around the worn ball there is easy.

Earlier pitman arms are lighter forgings, and an effort to save them is worthwhile. Rather than weld up the ball, I have on occasion replaced the ball using a new tie rod end ball as avaiiable from the vendors. I buy the earlier replacement ball which had the straight shank rather than the tapered shank. I put the shank in my lathe and drill the ball to take a 1/2" fine thread Then I use hand taps to create the thread in the ball, before cutting it off the shank.

On the pitman arm I use a belt grinder and a pair of calipers to make two flats opposite each other, using the calipers to keep the flats 1/2" apart.
Then I repeat the process to make a 1/2" square. The corners are then ground off to make 8 sides before the rest is rounded off to 1/2" round with a hand file. This round spiggot is still well larger than the neck at the back, so strength is not compromised. Nor is the metalurgy compromised by heat and the introduction of a different steel alloy if welding is used.

Hand tools are used to make the 1/2" thread onto which the ball is threaded. Loktite mounting compound is used on the thread, and a heavy tack weld used as an insurance against the ball ever screwing off.

It is a deal of work, maybe not worth the effort for a common item, but the harder to find early parts can be salvaged. Think DB and TW items.

Allan from down under.

[anothercarguy]

Speedytinc- Thanks that's good to know.

Allan- Thanks also good information- You have more patience and skill then me if you are hand filing round balls from squares. I respect that skill and dedication. Are you also suggesting that the unknown arm that I have might be a very early Pitman arm? The forging looks the same on both arms to me.

John

[speedytinc]

Is it possible this arm was straightened some?
I see a lump near the mount hole that could be evidence of some modification.

[Allan]

No John, it is not an early one. My suggestion was purely to indicate that the easiest way to fix it is to buy a new one.

There is no filing on the ball I use to rebuild an early pitman arm. All except the last bit is done on a linishing belt on my bench grinder. It is quick and easy. The only filing is done to make the ground section round enough for using a die to thread it.

The earlier pitman arms were forged by various makers like Dodge Bros, Transue Williams and Cleveland hardware. Stack them against a repop and you will see detailed differences in their appearance.

Allan from down under.