3 pt hitch repair

[MillWeld]

I made an adaptor many years ago for my Ford 641 (1958 model) and just found out how poorly I welded it. Towing a trailer laden with lumber, one of "V" arm's weld broke. The remaining arm held the load but it distorted the main body of the adaptor. (see pic) I ground off the "V" arms and re-welded them using plug welds to a frame made of 3.5" angle iron welded together to form a box. It is a much heftier design than the original.

However, I had difficulty attaching the lift arms and anti-sway bars to the pins on the new hitch but after much manipulation I found that if I lifted the lift arms and anti-sway bars I could align their eyelets with the hitch pins managed to get it mounted. In other words, the eyelets and pins are not well aligned at all elevations of the lift arms but by raising (or lowering) the arms the sweet spot can be found. In spite of the tight fit, the new hitch allows me to pull the load shown in the pic.

I concluded that the most reasonable cause is that the short, stubby mounting pins on the tractor must have been bent when the old hitch weld broke. As short as these pins are, it is difficult to see how they would bend but I can't think of any other cause. The new pins are welded co-linear and the 3.5" box tube is straight. The shop manual does not address the pin removal/replacement. Can anyone advise me on this?

 

[LD1]

I have no idea what pins you are asking about. And really no idea what you are even asking.

 

[MillWeld]

I had a difficult time writing an explanation. The short pins that I think may be bent/distorted are labeled 1,2,3,4 on the pic. where the arms attach to the tractor.

 

[LD1]

If pins 2 and 3 are tight leave em alone. IIRC, you have to do some tractor disassembly as there is a bit on the inside.

The short pins are easy to replace

 

[George2615]

There is a lot of twisting force where your re-rod is welded to the angle (circled in red) depending on tongue weight of the trailer you are towing. The draw bar with the angle wants to rotate when you lift anything.
Here's a couple pics of mine. Maybe you could strengthen yours by adding more bracing.

 

[Baby Grand]

... I had difficulty attaching the lift arms and anti-sway bars to the pins on the new hitch but after much manipulation I found that if I lifted the lift arms and anti-sway bars I could align their eyelets with the hitch pins managed to get it mounted. In other words, the eyelets and pins are not well aligned at all elevations of the lift arms but by raising (or lowering) the arms the sweet spot can be found. ...

I wonder if the hitch geometry is "over-constrained" and the anti-sway bars are fighting the lift arms. My suggestion is to try removing the anti-sway bars and replace them with check chains that will leave a little slack in the hitch so it can move enough to not bind. Check chains with a clevis on one end to fit the pins at the axle, and a turnbuckle with an eye sized to slip over the implement's pin. The turnbuckle would allow you to fine tune the hitch tension and avoid the binding problem.
Something like this:
Stabilizer Chain Kit New Universal 152235 | eBay

 

[bcp]

Check that pins 1 and 4 are in line with pins 2 and 3.

Bruce

 

[MillWeld]

I wonder if the hitch geometry is "over-constrained" and the anti-sway bars are fighting the lift arms.

I think this is the case. When towing, I have noticed the right anti-sway bar under compression but not the left. Such constraint was not present with the old hitch; this led me to think the broken weld distorted the pins. I will check out the chains as a solution. Thanks.
Bob

 

[MillWeld]

There is a lot of twisting force where your re-rod is welded to the angle (circled in red) depending on tongue weight of the trailer you are towing. The draw bar with the angle wants to rotate when you lift anything.

So right. The breaking of the weld testifies to that. The repaired version was plugged welded with a 6011 and the rest with 7018.

 

[MillWeld]

Check that pins 1 and 4 are in line with pins 2 and 3.

Bruce

Pins 1 and 4 actually have adjustable locations. They appear to be co-linear with pins 2 and 3.
Bob