Engine radius rods/anti-chatter rods on 1946

Ab4875

Ab4875

Senior Member
I’m putting the engine back in my 46 Business Coupe and am unsure if I have the correct parts for the engine radius rods. I have a round stepped piece with a conical depression that locates on top of the front cross member and that the front end of the radius rod sits on.

Underneath the cross member is another round piece with a conical depression. Underneath this is a flat washer followed by a spring washer and a bolt. Should there be a conical washer in place of the flat washer?
 

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Ford abandoned the "anti chatter" rods when they proved to be ineffective. I had a '46 sedan coupe that had them, and it chattered so bad that it rattled your teeth, and did about the same without them. Replacing the rubber motor and transmission mounts helped some, but when I removed the flywheel and had it resurfaced, it reduced the problem considerably. Chatter was a problem when the cars were newer, and when the clutch disk asbestos facing was banned, and an "organic" facing replaced it, the problem got worse. If the rear spring shackles are worn, or the spring mount is loose, the chatter will be affected. The torque tube design places the "push" on the transmission and engine mounts. As that assembly moves, it affects the clutch release as the linkage is attached to the frame. The faster you can engage the clutch, the less you will notice the chatter.
 
Thanks guys, I’ve had the flywheel and pressure plate cleaned up so I’ll try running without the radius rods.
 
Those rods can prevent engine to radiator contact under heavy braking or minor frontal impact. As for their effectivity at reducing clutch chatter the evidence is inconclusive at best.
 
I wonder if these after market kits are really any good? I installed these in addition to the OEM units because I had them. No chatter at all. However, there wasn't any chatter before I installed them and the car had the stock 85 HP engine. Engine is now an 8BA with stock anti-chatter rods elongated to fit bellhousing and also the units shown.
 

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My experience was a bit different. My '47 was difficult on the forward start and radical chatter on an uphill in reverse. During a transmission repair, the engine mounts were replaced and the clutch disc, and throwout bearing also. US made cars omitted the rods but Canadians retained them. The replacements did not fully solve the difficulty. Guessing that the clutch was another part of the problem. Post war or perhaps '42-'48 chatter rods are reversed, I think. Luckily I found a set complete and installed them. The reverse problem was much reduced but hardly cured. My imagination? Seemed that the whole thing seemed more solid. Not very scientific as I replaced too many parts at one time. The clutch remains a suspect. Lived with it. Good Luck: Fred A
 
I have never experienced clutch chatter in my '36 during the 95,k that I have driven it. The stock radius bars are still in the car.
Throughout the years it has been my observation that many people tend to "ride the clutch" in lieu of smoothly and quickly releasing it. Riding the clutch builds up head in the clutch disk which contributes to the chatter.
I have had Fords that had clutch chatter problems, however, it was usually in reverse.
 
My 41 has a rod that runs from the bell housing to the cross member at front of engine. It is not connected at the cross member, there is a bolt missing, if anyone knows what the thread size is, I would like to attach it. I don't have a problem with chatter now, but would like it to be attached, it would keep the engine from moving forward and get fan into radiator. Al
 
gom: I quite sure it's 7/16-20. If not, it's 1/2-20.
 

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I've had early Mustangs with bad clutch chatter because I beat the crap out of them. It wasn't the designs fault I warped the clutch disc or burned the flywheel.. I got a clutch hot and then went through a water puddle. It immediately started chattering after that. The only thing that could have happened was the cold water warped it.

At work sometimes the flywheels that had hard spots chattered and sometimes it didn't make any difference. I learned to always have the flywheel machined. We kept spare surfaced flywheels so we could just swap them. They always worked real nice if I had the flywheel surfaced.

Its probably a bunch little things that add up to the chatter.
I'm not even sure that the blue hot spots in the flywheel are not harder and the clutch discs grabs those spots differently So its not just an Early Ford problem. I think it was Hurst in the 1960s that made brackets to help keep the flathead front motor mounts from moving. I've never talked to anybody that had ever tried them.

On a car with parallel rear leaf springs the force to push the car down the road is being transferred from the rearend to the rear leaf springs and then to the car's frame or unibody. The driveshaft has a slip yoke so its never pushing on the back of the trans, unless you made your driveshaft too long. On a Early Ford the force to push the car forward is transmitted through the torque tube which pushes on the back of the trans. So the engine mounts , trans mount, engine steady rods and rear spring are what is transferring that force to the car's frame That pushing on the back of the trans will make the engine want to move forward and it will pull it backwards in reverse.

The clutch is no different than the cars of the 1960s and 1970s so I don't see why it would chatter. If the clutch is good the chatter is probably from the engine moving. Soft rubber motor mounts from getting soaked in oil could let it move. Front motor mounts that are not tightened enough might do it too. You need to prevent that engine from moving, Did the original front motor mounts fit tighter in the hole in the front crossmember. Do the aftermarket ones not fit tight. You just need to keep looking for all the things that would let it move. Do front mounted motor mounts let it move more than the mounts to the sides of later V8s?

When your braking you have the same problem. The rear brakes are grabbing the rearend, pulling on the torque tube to slow the car down. That's a lot of force applied to the motor mounts and chatter rods. A lot of the '32 chatter rods I see have been broken and welded back together. Those poor rods are a part of what is pushing and stopping the car. So then Ford made them a larger diameter and that helped with them not breaking. Then they redesigned the motor mount somewhere between '46 and '48 and decided they no longer needed the steady rods. I don't know what those mounts look like? If they are so great why would they not work on a'34 Ford?

Notice when you get to 1949 there are no holes in the 8BA blocks for the steady rods. That's because they went to the parallel springs on the rear and a driveshaft with a slip yoke. They didn't need the steady rods anymore.

Maybe even rear spring hanger bushings that are bad might let the rearend move a little. Which would let the engine and trans move too. Its all connected together. I bet when all that rubber is new there is no chatter.

When its all said and done its an antique. They were still getting the bugs out of designing cars.


I've never tried this but what if you were to apply the parking brake. Then you watch the engine while a couple of people push and pull on the cars bumpers and see if that engine moves.

I'd strap a smart phone in there aimed at the front motor mounts, start the movie and go for a ride. It would be really interesting to see what happens?
 
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