Steering arm curls...
 

The fact that folks are driving TF trucks with stock steering arms 60+ years after they were made is a testament to their durability. But I've said before that the 1/2 ton truck arms are part of the reason why folks often complain about the steering on a solid axle equipped truck, even if the truck has many new or upgraded steering and suspension parts. So I took a few minutes last night to capture the stock steering system in action. I started with the wheels straight ahead then turned the steering wheel until the steering knuckle hit the stop. Then I continued to apply and release pressure at the wheel.

I'm wondering if anyone else sees the issue I'm seeing.

https://www.youtube.com/watch?v=Qlk6fzx_GDc

Re: Steering arm curls...
 

That's interesting to see the flex on that arm and the drag link kind of twisting too. Not sure if the flex is designed in or not. I think a lot of people complaining about driving these old trucks and their steering are used to more modern/easier steering. Maybe someone with more experience can chime in and answer.

Re: Steering arm curls...
 

It does flex a bit but most of the movement appears to be in the worn end of the drag link.

Who ever was turning the wheel was also pushing against the stops pretty hard but driving down the road the flexing may actually dampen the jolts from the tire to the steering wheel.

I've never seen a broken AD or TF steering arm in 48 years of owning these trucks and looking at a lot of them in wrecking yards hunting for parts. I know from my own experience that the axles will bend back to the frame rail and not break.

Re: Steering arm curls...
 

You know the old joke, "Doc, it hurts when I do this," and the Doc replies, "Then don't do that."

In this case the Doc says "Don't turn the wheel while standing still." ;) :lol:

Re: Steering arm curls...
 

Too much! :lol:

I think the arm was made tough enough to flex. It's a damn strong part. I'm with Mr48 in that I've never seen a broken steering arm. But I also think tires and roads were different enough that the arm didn't have to be rigid. I promise that these arms flex while the truck is driving. With fatter or softer tires it will happen any time you try to turn the wheel when you're not moving. BTDT over 35 years ago. And if you live in an area with poor roads (like the Northeast) it happens on bumps or ruts or mismatched pavement. It doesn't take much force applied to the tire to get visible results. Truth is I can make it happen with the vehicle in the air by securing the steering wheel and trying to turn the tire from outside.

There's nothing wrong with the drag link. The joints at both ends are tight. The twisting seen in the video is the natural result of the pitman arm and steering arm movement.

And now I think we're at the heart of the issue. From the driver's perspective there's no significant change in the wheel feedback to indicate the knuckle contacted the stop. With most vehicles the steering linkage is rigid enough to alert the driver when the wheels require more force to hold or change direction. But in the 1/2 ton TF that just isn't the case. I had probably 1/8 to 1/4 wheel motion available after the knuckle hit the stop. Steering wheel resistance built up like a spring being compressed rather than a hard "stop."

Exactly! But it's not a good thing. When a rut, or a groove, or a bump applies enough force to a wheel to potentially change vehicle direction, most vehicles transmit that information to the steering wheel. The driver can apply corrective action quickly, based on the road feel. But in the TF truck the driver has to rely on realizing the vehicle is actually changing direction to apply a correction. Once the driver applies a correction there's a delay again in figuring out if it's the right amount of correction. The game of keeping the vehicle straight involves reacting and predicting in a way that most vehicles don't require. It feels like the road, not the driver, is in control.

Re: Steering arm curls...
 

Considering these trucks were mostly driving on dirt roads at low speeds and no one was in a big hurry and on non radial tires back in the day it’s no wonder they weren’t precise.
Even highway driving was at lower speeds .

That was one of the reasons I liked driving my ‘56 , it made one slow down and herd the truck down the road .

Re: Steering arm curls...
 

I like that "herd" comment. when teaching junior drivers to operate a fire truck (same style solid axle stuff) I would tell them to pick a point far down the road and drive in that direction. don't concentrate on the area 5 ft in front of the grille because you will constantly be correcting. stay between the lines but average it out. there will be some drift due to play in steering components and the generally how the road is crowned, cracks the tires want to follow etc. pay attention to the steering wheel feedback and do your best to counter that as required.
nowadays I drive a newer chevy with electric assist. I swear the old solid axle was easier to predict. if you take your eyes off the road for a sec you are in the next lane.
we have come a long way, haven't we?

Re: Steering arm curls...
 

G&R, thats a nice looking truck. I may trade in the tail lights personally, but that's just me. I would likely cut in some LED trailer lights into that awesome rear bumper.

Re: Steering arm curls...
 

Update: I have installed 3/4 ton arms in my 1/2 ton truck. They're a bolt on swap. I did end up getting ball stud adapters so I could reuse my tie-rod. And I had to adjust the toe at least 3/8" to account for the new steering arms.

I believe these arms make a noticeable difference. They are stronger and require more force to flex, so the driver will be more aware when the road providing steering input.

Pictures of the arms, 1/2 ton next to 3/4 ton, are attached. It's clear that 1/2 ton arms are not built to be as robust as 3/4 ton arms.

Next step is to work on rebuilding the stock steering box.

Re: Steering arm curls...
 

Well it is possible. My Son did it now granted it was with tires twice the size of stock on width, power steering pushing, while parking in a paved lot. With months of driving on a spindle that was sticking very tight. And he had a habit of hitting the stop and keeping the pressure on. Not you average everyday type of leverage that you would put on it normally.

Re: Steering arm curls...
 

Am I looking at it wrong or was it cracked for a while? I'm looking at the rustier spots in what appears to be the crack. Scary either way.

Re: Steering arm curls...
 

That was just surface rust. It was solid up to date it broke and he did a lot of parking lot turning that day. I don’t think it would have snapped rolling down road as they don’t get near the pressure of turning non moving wheels. I actually had it welded back together to get me steering around the yard while I found a replacement. Myself and my welder both noticed that the spot it broke did have a difference in material structure at that point like something was in the mix when cast. Like MR48 said he has never seen one broken me either until now and the shop guys I have worked with in past haven’t either. One of those really odd things.

Re: Steering arm curls...
 

I'm with Mick53 on that. It looks like it was cracked for a while to begin with and then abused to the point that it broke.

I've got the feeling that your son is one of those guys who can tear up steel balls with a rubber hammer in the middle of a sandpile. I forgot how many times i rebuilt the steering box on my next door neighbor's forklift steering box beause his workers would force the wheel to turn when it ran out of power steering fluid rather than go get the can of fluid and fill it. That included two of them pulling on the wheel to get it to turn at the same time and crushing the ball bearings. Guys who abuse and tear stuff up never seem to learn and just tear more stuff up.

Re: Steering arm curls...
 

Well sort of teens have learning experiences. He only tore up one set of tire. When he had to buy the next set. Let’s just say we got a whole lot more miles out of them. Having a few major failures on that truck taught him a lot. Now 7 years later he just fixed a flat on a plow disc in middle of field in 30 min and that included a trip to tire store. That and his employer only allows him to run the T8 because he is the only one who hasn’t tore it up and knows to shut it down when he hears a funny noise. That and a truck with bump steer kept his speed down.

Re: Steering arm curls...
 

I have seen mention of this steering arm flex before. Don't know if I have ever heard about one actually breaking tho. But this sparks my curiosity and interest about the 3/4 ton steering arm. Sounds like it is a bolt in swap, at least on the spindle/backing plate. What differences are there that caused you to need to adjust the toe? Do you still get the same full turn lock to lock without interferences?

Re: Steering arm curls...
 

If I remember right the 1/2t & 3/4t arms have different bolt hole spacing on the spindle so they dont interchange.

Re: Steering arm curls...
 

I have a '57 3200. I used arms from a '57 3800. the 3800 arms fit perfectly, with no modifications. The part number for OE arms are the same for all TF trucks. I don't have experience with any other swaps to say it works every time.

Re: Steering arm curls...
 

To the OP: What size tires and wheels are you running? When you are running ones wider than stock you're actually trying to lift the whole front end when turning due to the increase offset from the kingpin (scrub radius?). Similar to a go-kart when you turn full cock.

Re: Steering arm curls...
 

I'm running 215/75R16 tires. They're radials, and they're not 10 ply so they're softer than the ols skinny bias play tires.