Pitman arm interference issue

[gwillford]

I am currently installing a shortened pitman arm in my 30 Town Sedan. I have noticed that at full aft stroke, the nut that is on the bolt securing the arm to the steering box shaft is hitting the fender above it when the pitman arm is rotated completely aft to the point of hitting the stop bolt on the spindle. Enough to dent it… As a note, my drag link is stock and the steering arm on the left side is not bent. There are new cups and springs in the drag link as I rebuilt it when rebuild the complete front end. I have 2 1931 As locally to compare to dimensionally. I have discovered that the gearbox mounting holes are about ¼ in higher (closer to fender) on a 30 than a 31. My frame is not bent or altered. It’s how it was made from the factory. So, my arm sits close to the fender above as built. The extra stoke of the short pitman arm doesn’t help with a marginal clearance. That’s the background, now the question. Anyone else experience this? Are all new shortened arms coming from the same supplier? To the eyeball, the pinch bolt does seem to sit a little higher above center than my stock arm. Anyone else encounter this? Fixes tried and working? Thanks for the input!

[nkaminar]

You may try an adjustable drag link. There was a thread about this recently.

[gwillford]

Thanks for the suggestion. Per all knowing Google, I have been unable to find a source... Contacts anyone?

[Bruce of MN]

From a forum search: https://www.fordbarn.com/forum/searc...rchid=30092624

[alexiskai]

You want Dave Delmue's adjustable drag link. He makes them in batches; I don't know whether there are any unsold units from his last batch. Dave also is a builder for the Burtz block and he makes adapters for the F-150 transmission. An extremely valuable individual. His email is [email protected].

[katy]

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Originally Posted by gwillford

the nut that is on the bolt securing the arm to the steering box shaft is hitting the fender above it when the pitman arm is rotated completely aft to the point of hitting the stop bolt on the spindle.

A picture would help.

[Marshall V. Daut]

Check that the bolt holes have not been elongated by wear or someone's attempt to modify the frame for a different steering box in the last 95 years. I have seen holes that were worn egg-shaped and some that had clearly been drilled larger. Generally, though, when the holes have been enlarged through wear or intent, the steering box follows the law of gravity and sits lower inside the frame rail instead of up higher. Your problem appears to be the opposite.
Push one of the correct mounting bolts through a hole and see if it is a loose fit. It should be tight, with little or no slop. If it's loose, you may want to weld the upper portion of the holes and then use a cone bit to make the hole round around again and of the proper diameter. I have had to do this in the past on frames with radically worn holes because someone allowed the steering box to become loose in the frame. The loose bolts wore the mounting holes oversized.
Also make sure you have the correct pitman arm bolt. Lots of guys use hex-head hardware store bolts that are too soft and require a larger nut. If your car is close to the limit for proper steering box location, an improper nut that is too large just might be the problem. It's a close fit anyway between the back of the pitman arm and the fender.
Marshall

[gwillford]

Appreciate the input Marshall! Good comments. Hole integrity was an early thought also. Bolts fit properly and no appearance of welding or modifying. I even cleaned off the paint some to check. I was surprised that the two 31s I checked had holes that sit lower in the frame. Maybe I am just at the end of the tolerance range. Never the less, it is what it is. I have come to realize same about the nut. A new one ordered is actually a larger hex size... I am using the small. I may turn the hex back a bit from the castled end for a little more clearance. Have also noticed the springs that came with the Teflon EZ-Steer kit I installed also are about an 1/8 longer than my 4 stock ones. That will move my drag link aft a bit aggravating an already close fit. I am beginning to think that this will be a battle of small adjustments here and there. If I can't resolve, I can go the route of an adjustable drag link. Appreciate all the inputs. Feel free to continue.

[Brentwood Bob]

When I welded up and redrilled my frame I used the holes on the passenger side as my guide. Made a pattern with cardboard and spray paint. Then welded up one hole, marked it and redrilled. I had a brass bracket, probably an early aftermarket fix, to fine tune the new hole with the bracket bolted to the remaining original hole in the frame. Then reversed the procedure to get the other wallowed out hole done.

[ChicagoBob]

Maybe put a washer or two under the spindle stop bolt?

[MARKA]

Hello ,
I have the same identical problem as you have .

A 1930 Coupe with short Pitman arm. I also have the eze steer teflon cups in the ends of the drag link and new springs installed as supplies with the kit.
The nut on the pitman arm hits the underside of the fender at full steering lock.
It has put a tiny dent in the guard , but I just live with it.

I figure it is a small price to pay for the benefits of using the shortened pitman arm.

Mark.

[ursus]

I found the same problem in my '31 coupe. The steering gear mounting holes had become badly ovaled out and resistance from from the fore-and-aft movement of the drag link caused the Pitman arm bolt to cam upward towards the fender. This was a protracted process so was barely noticeable to the driver. That is, until I discovered a small hole forming on the top side of the fender.

[Marshall V. Daut]

Another thing to check will require two people. Unless you replaced and reamed/honed the new sector shaft bushings, the sector shaft will move up and down when the steering wheel is turned, mostly upwards. That might be just enough to allow the pitman arm nut to interfere with the bottom of the fender. As I previously wrote, there isn't much clearance between the two at that juncture in the turning arc anyway, so any slop in the sector shaft will close that minimal gap in a hurry.
While someone else turns the steering wheel back and forth 1/4 turn, bend down and watch the action of the pitman arm. Ideally it should not move vertically at all. In the real world, though, there will probably be a little up and down movement due to wear in the two brass sector bushings. The sector shaft itself is rarely at fault because it is harder than the brass bushings, so the bushings wear out first, creating slop. If you didn't replace these bushings, it's HIGHLY likely that a previous owner/"restorer" didn't, either. It's not a fun job in the average, non-machine shop type of owner's garage: removing the steering column from the car, disassembling it, removing and installing these large bushings and then hand-reaming/honing them to exacting tolerances in order to reduce lubricant leakage and slop. Then the column has to be re-assembled, adjusted to factory specifications and finally re-installed in the car. So, you can see why a lot of guys simply skip this bushing replacement step in the restoration process and call it a day.
To wit: I am presently working on two 1929 Model A Roadsters at a local specialty car shop with this problem. The beautiful paint, new tops and interiors and EVERY chrome accessory available from the vendors are all present, but such things as properly rebuilding the steering boxes were conveniently ignored. SURPRISE!!! Anyway, the roadster with a seven-tooth box is the worse offender of the two for slop in the sector bushings. Its pitman arm bolt nut hits the bottom of the fender and there is a 1/4 turn slop at the steering wheel = full rebuild coming up. I am confident that after going through the seven-tooth's box especially, the pitman arm nut interference problem will go away. Maybe that is also contributing to your situation? Check it out with a friend.
Marshall

[gwillford]

All, certainly appreciate the time many took to pen a helpful response. This why I like this forum. It's finally Friday and will have a little more garage time. Will update as I work for a resolution to the way my car was built. Will post pictures if I can figure it out. An additional note. I rebuilt the steering box so all gears, bearings and bushings are new. I saw what you mean about the shaft moving Marshall. You are correct as not fun! A couple of updates. Using the original springs with the teflon caps helped. I noticed on my short pitman arm that the bosses on the top were not of equal size. extra large on the nut side of my arm... That doesn't help. Snyders was very helpful with checking their inventory to see if all had a pattern shift to the right. Yup. I had a friend spot face this boss to about 1/8 in shorter. Also using a small castle nut (aircraft). Had to shorten the bolt as well as drill the new cotter pin hole in a manner that placed the flat of the not directly on top. Like I said earlier. A little here, a little there... Stay tuned. George

[gwillford]

Final post. The pitman arm pinch nut is still pretty close when rotated aft but it clears. Solution was as described in my last post. Biggest benefit was machining the pinch bolt boss as mentioned and using a shortened bolt. Thanks all.