rear radius rods

Dick M

Dick M

Well-known member
A fellow Model Aer has the t-10 5 speed in his 31 town sedan. His starter hung up on the ring gear. He tried to dislodge the starter by pushing the car backwards and poped the clutch in reverse. He severely bent both stock rear radius rods in the process. My question is: can anyone tell me where I can purchase the reinforced radius rods--either the type that has a steel bar running up the inside of the rod or one that is cast and is stout?? Thanks in advance for any help.
 
A lot of guys forget that with an open driveline rear end, the radius rods not only have to take up the rotational force but the 90% of forward driving force.
(10% through the spring and cross member)
They need to be SUPER stout. I know there are several companies making kits but have heard that at least one kit is no where near strong enough for anything but the weakest stock engine.
We make our own as needed, with a tapered ladder type design and attach them to a belly band so it doesn't screw up the handling.
 
I found reinforced rear radius rods at AUTO RESTORATION, telephone 800-955-3139. The cost is $210.
 

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Bob C said:
Here's a picture.
Click to expand...

While what is pictured will work what with the limited travel of a model A rear end, the proper practical anchor point of the radius rods is directly below and close to as possible to the u-joint.
The THEORETICAL proper anchor point would be at the center of the cross of the u-joint as in a torque tube drive.
With the setup in the picture, the forward driving force on the car is through the transmission case and consequently through the motor mounts. Not good. It could push the fan into the radiator with a strong engine.
 
big question : do they float with the rear end ? mine were bolted to the bottom of the trans , but solid . not a lot of rear spring action . i ended up using heim joints to asure travel . made a difference ! before they were attached to the tork tube & thus moved with the rear end ............
 
V4F said:
big question : do they float with the rear end ? mine were bolted to the bottom of the trans , but solid . not a lot of rear spring action . i ended up using heim joints to asure travel . made a difference ! before they were attached to the tork tube & thus moved with the rear end ............
Click to expand...

They are bolted solid to the rear end and should have some sort of joint at the front like Hiem or truck tie rod end.
Here is a pic of the way I do them. This is on a front end but the rear is basically the same.
 

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Here's a picture of what I did, since this picture I've added a panhard bar from the rear diff. to the frame. Not real original looking but it's on a Speedster so stability was more important then appearance.
 

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usered said:
Here's a picture of what I did, since this picture I've added a panhard bar from the rear diff. to the frame. Not real original looking but it's on a Speedster so stability was more important then appearance.
Click to expand...

You might want to fill the "Y" in with a solid gusset at the back of the radius rods.
The front anchor points will work fine if you don't plan on doing much cornering.
 
Has anyone had experience repairing rear radius rods? Although mine still seem to be strong and straight there are signs of rust through on the sides by the rear wheels in a couple of spots. I was thinking of welding some metal along the sides to fix as opposed to purchasing new ones somewhere. Any advise is appreciated.
 
Auto Restorations no longer supplies reinforced rear radius rods for Model A. Does anyone know of another supplier?
 
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