I'm still learning about m '55 850 front axle

tripper225 · Sep 15, 2019

I posted earlier about the radius rod interface with the front axle on my machine. I was concerned about the axle rotating on a centerline perpendicular to the radius arm pivot centerline. I found that the previous owner used the tractor with the bolts for the radius rods through the front axle were sheared of on the bottom side and the bolts were bent pretty bad. I have chased that condition around trying to insure that I don't run into the same problem. I have straightened the radius rods and replaced the axle pin and bushing.
Now I came across something in the manual that changed my thinking altogether, the yoke bolts in the radius rod/axle interface are torqued to 75-135 ft-lbs. There is no possible way for the radius rod to change orientation to the front axle with the yoke clamped to the front axle. The radius rods are going to bend every time the axle rotates on uneven ground. No wonder I have read about users that use soft shims to quite the ball joints for the radius rods.
Please comment on this if I have misinterpreted this design aspect.

Thanks for you help

cdmn · Sep 15, 2019

You are correct. Ford always had the radius rods on their cars go back to a single pivot point
under the transmission. This was also done on Fordson tractors, (except Dextas) and most other tractors. This is kinematically correct.

By spreading the radius rods to the sides of the tractor, you introduce a twist, which could be taken up by bending of the radius rods, or by torsion in the front axle. In hotrods, you see the extreme of this when the radius rods are spread out to the sides of the frame. Luckily, steel has a high tensile strength (or elasticity) which allows it to snap back after being deformed. Over time, the fatigue stress may induce cracks, but they didn't expect anyone to be worried about that 50 years later.

I expect that they did a lot of testing to see whether the design held up, or if they needed more elastic alloys. The other approach would be to sell low-cost replacements from time to time to keep the tractor in service.

tripper225 · Sep 19, 2019

Thank you for reply. I'm going ahead with current conditions of the radius rod to the axle interface. I have the front of the tractor in the air and I hear the ball of the radius rods hammer the sockets when I rotate the axle so, I'm going to use a soft shim (aluminum) to mitigate the ball impact at the socket end of the radius rods. Time will tell if the outcome will be positive.

Keep posting,

JMOR · Sep 19, 2019

(quoted from post at 10:05:38 09/19/19) Thank you for reply. I'm going ahead with current conditions of the radius rod to the axle interface. I have the front of the tractor in the air and I hear the ball of the radius rods hammer the sockets when I rotate the axle so, I'm going to use a soft shim (aluminum) to mitigate the ball impact at the socket end of the radius rods. Time will tell if the outcome will be positive.

Keep posting,

ime will tell............at 64 so far. Will it make it to 70?

I'm still learning about m '55 850 front axle

tripper225

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cdmn

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tripper225

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JMOR

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