WHY ???????????????

[oldnslo]

The top link rarely has the forces on it that the lower arms have. It is mainly used for lifting the implement or keeping the implement from rotating forward during use (unless you have draft control) and thus less stoutness. Not excusing the lack of a "single" pin that would fit all - just an explanation. Maybe it is an economic issue although the prices are not that much different.

My guess would be what GW said in that the top link does not see the forces the lower links do.

Roy

 

[LD1]

To make it even more confusing, some tractors, like our JD2040 has cat II lowers and a cat I toplink:confused2:

 

[955Lincoln]

To make it even more confusing, some tractors, like our JD2040 has cat II lowers and a cat I toplink:confused2:

Same here, I thought mine was the only oddball out there. To add a little more confusion into the mix, cat II lowers but best used with cat I spacing because mine is a narrow vineyard tractor. Cat II spacing will work but the arms are angled out. No big deal, just weird looking.

 

[LD1]

Same here, I thought mine was the only oddball out there. To add a little more confusion into the mix, cat II lowers but best used with cat I spacing because mine is a narrow vineyard tractor. Cat II spacing will work but the arms are angled out. No big deal, just weird looking.

Is yours a 2040 as well???

 

[MMagis]

Some @#$%^& engineer figured the top link didn't need as much strength.

That @#$%^& engineer was right. Basic physics. This is a rare case where it likely has nothing to do with price.

 

[955Lincoln]

Is yours a 2040 as well???

Italian Carraro tractor.

 

[TRR]

Not only are the pins larger, but the spacing is further as well.

 

[beenthere]

Why?

Why not? :confused3:

 

[jinman]

I think the definitive reasons have already been touched on, but toplink pins are usually captive on both sides of the rotating ball hitch in the toplink. Many/most sidelink pins are captive on one end only and float at the outer side so a lynchpin can be inserted. Because of this, the toplink is reduced in size since it has better support. I think newer large implements such as heavy boxblades, discs, and cutters have both sides captive sidelinks, but most didn't when the spec was written. As stated, toplinks don't bear a lot of weight unless lifting a very long implement like an 8' rotary cutter or big 10' disc. Then, the toplink takes probably nearly as much stress as the sidelinks.

...and I'm pretty sure if the toplink was the same as the sidelink, you'd see a lot of sidelinks used as emergency toplinks as shown below.:laughing:

 

[SixHoeBob]

I think Harry Ferguson(?) established the pin sizes in 1939 when the 9N was first built. He was the mastermind behind the three point hitch. Why would we want to fix a problem that doesn't exist. Go to TSC and by some pins of the correct diameter and some good lynch pins to go with them. Take care of the pins, and they will last longer than the tractor. Take pride in using the correct hardware to do the project. Anyone can do a project in a half-a$$ed manner, but why not try to go about it correctly?

If people wanted to save money, they would demand an affordable (simple and plain) car and pickup. But that boat has sailed.