I purchased a restored chassis recently, and it came with a collection of spares. Among them were these three pitman arms.
The one on the left is about 1/2" longer than the other two, and it shows just .002" out of round. The other two are the same length but are at markedly different angles. If the rusty one is bent, it shows no evidence of damage. What was their application?
Allan from down under.
Here are a couple of earlier threads about this:
https://www.google.se/url?sa=i&source=images&cd=&cad=rja&uact=8&ved=0CAUQjB1qFQo TCK2ywfuFg8kCFUKKLAodf10Cnw&url=http%3A%2F%2Fwww.mtfca.com%2Fdiscus%2Fmessages%2 F411944%2F452557.html%3F1402878003&psig=AFQjCNHumnmKqAIzAYH8WAOMZzqFClvTUQ&ust=1 447148071936353&rct=j
https://www.google.se/url?sa=i&source=images&cd=&cad=rja&uact=8&ved=0CAUQjB1qFQo TCO38sKOGg8kCFQsQLAodJNQAjA&url=http%3A%2F%2Fwww.mtfca.com%2Fdiscus%2Fmessages%2 F118802%2F140118.html%3F1273477185&psig=AFQjCNHumnmKqAIzAYH8WAOMZzqFClvTUQ&ust=1 447148071936353&rct=j
Roger's links do not work for me. Try this one:
Ford changed every part of the steering system over the years. You are showing examples of different designs of Pitman Arms. You need to make sure all of the steering parts are from the same era in order to have a safe Model T to drive.
Royce, that's a good point. But what about the pitmans offered by the usual vendors? I don't recall them listing the as any specific year's app. Could we be screwing up our steering systems with these otherwise generic arms? I've only put on two new ones, one on the '25 TT firetruck which is now gone, and on my '15 Touring, which I'm still running. Just wondering.
The dimensions and specs did change over the years, but the 1927 parts book lists the last version, part #929C, for 1909-27.
The dimension from the center of the ball to the firewall side of the shaft housing (measured at 90 degrees) was 2-27/32" in 1910, changed to 3-11/32" in 1916, tolerance to 3-5/8" added in '23, and changed to 4" in 1926 when the part number changed to 929C.
The dimension from the center of the ball to the center of the shaft hole (also measured at 90 degrees) was 4-1/4" in 1910, changed to 3-11/16" on 929C in '26.
The part number was moved to the shaft hole housing in May of 1914 and the Ford script was added opposite that part number in 1916.
The one on the left looks like it would be for a 26-27. The angle was changed because of the lower car lowered the angle of the steering column. The one on the right is for an early car. I don't know about the one in the middle, but I think it would work on a 26-27.
Be very careful with mixing front end parts from the various years. Fords was making a lot of changes and a mix-match of parts can be dangerous with the steering control (ie over center etc).
Don't ask how I discovered this.
RV, Roger's post led me to your drawing of the differences in the arms and the dates of the changes. The centre one in my photo is near that for the 1917 arm. The other two are not within cooee of any of the others listed.
I will check them against the original arm coming out of the car, hoping that the one on the left is a match, as that shows negligible wear.
I too, wonder about the one repro arm being offered by the vendors as a fits-all item, given the problems of mixed components in the steering department.
Allan, the "fits-all" that I was referring to is from the 1927 Ford parts book, not a vendor catalog. Ford said that 929C would replace all earlier arms.
Differences from one arm to the other would merely change the angles of the drag link and would have a negligible effect on the actual steering. The main motivation for my posting of the dates and changes is just for dating the arms.