Radius Rod...use the rubber ball or not

German guy

German guy

Senior Member
While surveying the underside my A a few weeks ago for another project I noticed that the radius ball looked odd. Getting a light and working my way underneath I noticed that the rubber ball had been shredded and ragged parts of it sticking out around the periphery of the joint. I have battled with a mild case of 'wobble' and replaced a lot of components to no effect. It only happens rarely...but that is enough to panic my wife...and is not very appealing to me either. I watched a few videos on the topic and repairing the radius rod ball joint was recommended as one fix. So...I bought the Snyder's A-3440-RE Replacement radius ball cap assembly (which includes a rubber ball) and intend to install it in a few weeks.



Here is the question: Both videos I found stated to forget about replacing the rubber ball, and assembling the repair kit without it. Now...I generally assume that Henry's engineers did not include parts that were not needed...so Pros and Cons? Opinions anyone? Rubber ball or no rubber ball?
 
.I generally assume that Henry's engineers did not include parts that were not needed...so Pros and Cons? Opinions anyone? Rubber ball or no rubber ball?
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Henry's engineers ultimately went to a rubber ball solution after experience with the Model A and transitioning into the Model B and Model 18 (V8.) Also most Ford tractors and other motive power.

You look at the Parts Price List after 1932 and you can still find the solid ball setup, but you also find the rubber ball setup. New cars after 1932 were exclusively rubber ball.

I have used both. I found no difference in the driving of the car. The solid ball setup DOES wear the ball, but the wear tends to be "localized." I imagine the rubber ball setup wears too - but the wear seems more "generalized" - and perhaps that is the reason for its ultimate adoption by Ford?

The nice thing about the rubber ball is that the rubber ball is CHEAP and easily replaced. If the car were a regular user - about annually is about right - similar to my maintenance experience at Stuart Farm locally. (I worked there as a mechanic for about a year after my unemployment occurred.)

So do as you will. The original setup IS interesting when you see it. Perhaps that is reason enough?

Joe K
 
From an engineering standpoint rubber is not the correct material for this high stress area. Maybe Delrin, but steel was used originally for a reason. Just a couple of days ago I climbed under my car to check the ball with a pry bar. No looseness or play so I am happy. Modern cars do use rubber in suspension components but it is polyurethane, a tough material.
 
nkaminar said:
From an engineering standpoint rubber is not the correct material for this high stress area. Maybe Delrin, but steel was used originally for a reason. Just a couple of days ago I climbed under my car to check the ball with a pry bar. No looseness or play so I am happy. Modern cars do use rubber in suspension components but it is polyurethane, a tough material.
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I like the idea of delrin for the ball, now if we can just get some made :)
 
About the Ford's use of "rubber ball".

I suspect this setup worked well in later years because Ford used "REAL RUBBER" to make the balls NOT the recycled inner tubes and recycled tire rubber being used these days by the Bean Counters when they order the manufacture of parts.

The Chinese WILL use real rubber UNLESS you want CHEAP!
 
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Just yesterday I removed the rubber radius ball that I installed 30 years ago. It was still in perfect shape with no softening, shredding or distorting.

It was installed with the complete kit, which is an important point. Our club has an annual spring safety check and we have found many horrible loose radius rods caused by combining some parts made for the rubber and some for the stock setup.

The top piece of metal for the stock setup has a hole in the middle so that oil that leaks out of the transmission shifting rails falls down onto the radius ball felt (A-3425) goes down the hole and lubricates the steel radius ball. The top piece of metal for the rubber setup has a solid circle of metal to keep oil off the rubber ball. Incidentally, if you install the new aftermarket front ****** seal (A-7112-S) you should periodically lubricate the steel radius ball.

Besides the different shapes of the two metal pieces that surround the ball, the stock setup uses the radius bushings (A-3435) and springs so that the clamping force on the steel ball is kept tight by the springs, yet has some give if you bang your front wheels straight into the curb. The rubber setup bolts up tight.

My own conclusion is that both the stock setup and the rubber ball both work well, but you cannot combine parts from both systems. The clamshells look like they are interchangeable, but they aren't. Pick one system and do it right.
 
Ford didn't have delrin and other abrasion resistant plastics to work with like we do now. They always wanted a ball that would go over the radius rod ball end as a cushion but it's just too soft. They worked for a while but quickly wore out. The metal on metal works but it needs some lube or even a little high EP grease on it now and then/ That's why they put that felt pad over it was to catch some seepage from up in the clutch and bell housings.

I've found the bores in the housing for the cap bolts so worn that I had to find some drill bushings to fit down into the worn bore so that the pin would still keep the bolts from turning. Those bolts have to be right to hold the lower cap solid. All that stuff takes a beating if you drive on old country roads like grandpop did.
 
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Snyder's sells a metal shim (spacer washer) to place on top of the ball using the original two cup plates, spacers, springs and nuts. After I installed that spacer washer and installed the original parts, I had a gap between the upper and lower cup plates. I didn't have that gap without the spacer washer!
Buy the spacer washer and try it.
 
Herb Concord Ca said:
Snyder's sells a metal shim (spacer washer) to place on top of the ball using the original two cup plates, spacers, springs and nuts. After I installed that spacer washer and installed the original parts, I had a gap between the upper and lower cup plates. I didn't have that gap without the spacer washer!
Buy the spacer washer and try it.
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Years ago, I tried one of those washers and by the time I got to the end of my driveway, it had migrated to the under side of the ball so I added a tack of weld to hold it. No good! I ended up building up the worn ball with weld and shaping it fairly accurately back to the intended 1 1/2 inch diameter.
 
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Regarding the softness or durability of the rubber balls...

My mind goes to the rubber tired dolly wheels bought from Harbor Freight. Sourced of course from China. Who is FAMOUS worldwide for their "uncured" rubber.

Open the box of dolly wheels and practically pass out from the smell of solvent used in production of the rubber wheel cover. And the rubber tired wheels didn't last so long before moving something heavy held by the home-made dolly - and the tires "unroll" in tracks on the concrete floor.

So like many of these things - quality varies. Unfortunately I don't know of any proof of quality assurance in the production of this Model A part.

Maybe there should be?

Joe K
 
Henry went to the rubber ball because of cost. Fewer parts, simpler design.

Both work well but the rubber ball may need to be replaced every so often.

Chris W.
 
I saw some in the 70's and 80's that turned to slime from the oil.I put one in my pickup in 04,it really needed the ball and the bellhousing fixed to use the original setup.I never got to it,and I have it apart right now.I washed the oil off the rubber,and am going to reuse it.It just has lines from the pinch points,but is sound,and I know the condition of it.Two teaspoons and some KY jelly and that rubber slides right onto that ball.I know some guys have said that it affects the caster,but by how much? In real life,does it make a difference in driving?I always felt that was more armchair theory than fact.
 
Two things:

Changing the caster changes the toe-in. Check the toe-in after you finish up repairing the ball.

You can buy rubber grease that is formulated for use on rubber. Some of the normal grease can cause damage to the rubber. You know this based on your use of KY jelly,.
 
How do you put the rubber ball with its small opening over the much larger Radius Ball?
What tool you use or do you cut off a little to make the opening larger? Thanks.
 
Setra said:
How do you put the rubber ball with its small opening over the much larger Radius Ball?
What tool you use or do you cut off a little to make the opening larger? Thanks.
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Warm the ball in soapy dish water.
Grease lightly both the interior of the rubber - and the ball on the wishbone.
PRESS the open end of the rubber OVER the ball, stretching the opening.
It may take a bit of a push. There is no telling how long your rubber has been sitting on a storeroom shelf - and age is the enemy of resilience.

I wouldn't "cut" the ball to ease this process. Also be aware should the ball "split" as you push it over. You don't want that. Reason to complain to your supplier about the quality of his goods if it does.

Joe K
 
Use two teaspoons and whatever lube you want to.I believe any of the balls you buy now are impervious to greases and oils.I use KY jelly because I use it a lot on rubber bushings and o rings,and because there is a tube of it in my toolbox.
 
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