Spark Rod/Pitman Arm interference, fan opinions

[BigBen]

Everyone,
I've been installing a new firewall in my '22 touring. I started to button everything up today and I noticed this little interference issue. I installed a new Pitman arm and it is interfering with the end of the spark rod when wheel is cut hard to right and the spark lever is all the way up(retarded), when the lever is moved down, the rod moves up in the column a little and doesn't seem to be in the way. I did notice before I put it on that the key way on the two Pitmans(original and new) was just a tiny bit off, but now that it is on I can't remember to which side it was off! All parts other than Pitman are original, only thing replaced on steering column was the bracket bushing. I will post two pictures. I really don't want to cut or grind anything if I can help it, so I'm asking for opinions.
Thank you for any help you may be able to give!

First pic is of the rod/lever all the way up/retarded and wheel hard right

second is of rod all the down/adavnced and wheel hard right

Also, does this fan blade look cracked? or just some kind of score maybe from a screwdriver or something of the like?
I thought it was a little too straight for a crack.

Any opinions are appreciated. Thanks, Ben

[Norman Kling]

I just looked at my 22 and also at my 26. The arm for the spark lever goes upward from the rod and over the pitman arm. I'm sorry, i don't have one of those "New Fangled" cell phones which also take pictures and can immediately unload to the computer, but I think the slot for the key in your new pitman arm might be machined wrong. I turned mine all the way to the right and it did not come as far as yours. When the wheels are pointing straight ahead, the pitman arm should be straight down. The movement would be the same distance in either direction. If it did not cause interference with the old arm, I would suspect either the length of the arm, the angle of the arm or the cut for the key is incorrect for that car. There are different pitman arms for different year cars due to the angle of the steering column due to the height of the body from the frame.
Norm

[Norman Kling]

That looks like a scratch on the fan. If it is a crack, the fan should be discarded, so try to flex it a bit and if it bends sharply at that location it is a crack. They don't usually break at that location, but more likely to break at the connection to the hub.
Norm

[Norman Kling]

One more thing. The drag link might be too long. Some cars also had a different length drag link.
Norm

[John kuehn]

If you have an old pitman arm good or bad shape that’s an original see if there is any difference in the key way. It might be off. Also I’m not sure but it seems like there was an early post about some changes that occurred along the way with pitman arms.

I think this was one of them and it’s interesting. https://www.mtfca.com/discus/messages/4 ... 1402824133

The last entry on this particular post has an entry in the later Ford parts book showing the 27 pitman arm fitting T’s from 09 -27 when the Ford drawings showed slight differences thru the years. So which is it ???

[BigBen]

Yeah, the original Pitman's key slot was in a different position, only slightly. The parts houses seem to list them for '09-'27, there are probably all made in one mold anyway. I'll make some calls to them on Monday and pick some brains. Maybe I'll just put the old one back in!

[speedytinc]

Repop parts!. This is one of those parts that I weld the ball Up & hand grind back round to the original diameter or a bit larger to account for steering link joint wear.

[Allan]

If you took the old one off due to ball wear, the ball can be replaced with one from a tie rod end ball. Ask me how if you want to go that route.

Allan from down under.

[BigBen]

I'm going to take it off and take picture. I don't have the welding skills to weld a new one on, or the welder for that matter. I didn't necessarily replace it due to wear, just thought it needed a new one after 100 years! I'll call a few places on Monday and see what they say, they are probably all the same anyway.

[TXGOAT2]

Does the gearbox under the steering wheel play any part in limiting the maximum rotation of the steering shaft?

[Allan]

On the later T's one of the planetary gear pins extended through the flange on the end of the steering shaft. This extended pin ran in a curved slot milled into the base of the steering case. This did limit how far the steering shaft could be turned before the pin engaged on the end of the slot.

Allan from down under.

[BigBen]

Does the gearbox under the steering wheel play any part in limiting the maximum rotation of the steering shaft?

I was going to take that apart sooner or later, looks like it'll be sooner. I'm trying to get this darn thing back together because its 100th is next month, I'd really like to drive the thing! I'm going to try to put the old one back and see what happens, stay tuned, story at 11:00

[Mark Chaffin]

Your spark rod appears to be protruding to far forward of the steering bracket. You indicate to replaced the firewall. Did you go from a wood firewall to a metal firewall? Also, the firewall mounting brackets are different for both the wood and metal firewall due to the thickness of each one. If you use wood firewall to frame mounting brackets with a metal firewall, it will move the steering column forward about a quarter inch. In turn, it will create the problem you are experiencing. Since 1922 was a transition year (wood to metal firewall) this may be your problem.

[BigBen]

Your spark rod appears to be protruding to far forward of the steering bracket. You indicate to replaced the firewall. Did you go from a wood firewall to a metal firewall? Also, the firewall mounting brackets are different for both the wood and metal firewall due to the thickness of each one. If you use wood firewall to frame mounting brackets with a metal firewall, it will move the steering column forward about a quarter inch. In turn, it will create the problem you are experiencing. Since 1922 was a transition year (wood to metal firewall) this may be your problem.

No, I went from wood to wood, the new firewall is just a bit thicker though, not sure if that matters but, shouldn't the steering column flange be in the same plane as the original firewall?

I did take a picture, new on the right, original on left. May be hard to see in pic, but the keyway is just a little off, and it would to the side that matters. Oddly, the old one is about .060" wider in the area where it's hitting.

The new one is a bit shorter too,

The kicker is this though... I put the old one back in and it did the exact opposite as the new one! Instead of hitting with the spark lever up, old one hits with it down! Upon further inspection it also seems the rod is a little bent, I will try some gentle persuasion on it and the pitman is probably something a little tiny touch up with a Dremel can fix.

Of course, I never thought to look at it before I took it apart!, I've been around the car my whole life and it always seemed to be fine, why look at it rightr?!

[TRDxB2]

The steering shaft, spark & throttle rods are fixed at the steering box. These positions, relative to one another, don't changed by thickness of the firewall or steering column year. Some pictures from the WEB don't look much different than yours.

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You might be able to remedy it with a different lever like. For example the 2 pin throttle lever could be used to move it back towards the firewall a bit. However the longer arm will have an effect.

[John kuehn]

Can you tell if your old pitman has any marks or wear on the side that faced the control arm ?
It may have been hitting or rubbing and you didn’t notice it.

If it was working good you may not have noticed it??

[BigBen]

Can you tell if your old pitman has any marks or wear on the side that faced the control arm ?
It may have been hitting or rubbing and you didn’t notice it.

If it was working good you may not have noticed it??

I did look. I does have a mark there, which led me to believe it was doing it all along and I just never noticed!
I'm going to give the new one a tiny little kiss with the Dremel and see what happens.

Thanks for all your input!

[Mark Chaffin]

If you are using a wood firewall, everything should be just fine. If you did change to a metal firewall and continued to use the earlier style firewall mounting brackets it would cause the spark and throttle rods to move forward in the steering column to frame bracket. Yes. The spark and throttle rods are fixed in the steering column but not in the lower bracket. That is why the earlier wood firewall brackets differ from the 23' to 25' metal firewall brackets.

[John kuehn]

Glad you found the issue! I suppose since we live and work in a different era and use to our modern cars that have overall closer tolerances in their fit up we tend to think our Model T’s are the same or close to it.
Not So!

Years ago when I became interested in T’s it became apparent they were crudely built in a way and thinking about it we are having fun with 100 year old technology. But they were reliable enough to have over 15,000.000 built!

[BigBen]

Glad you found the issue! I suppose since we live and work in a different era and use to our modern cars that have overall closer tolerances in their fit up we tend to think our Model T’s are the same or close to it.
Not So!

Years ago when I became interested in T’s it became apparent they were crudely built in a way and thinking about it we are having fun with 100 year old technology. But they were reliable enough to have over 15,000.000 built!

I think you have something there, John. Crudely built, but it works! Just like the AK47.
Now I need to tell myself that it's OK, it's been like that for the last 100 years. All goes well, it'll outlast me!

Thanks everybody!