A-Frame to plow pivot point question

[blades]

I have a 6.5' Meyer plow, and am wondering how much "slop" or free-play there should be where the plow attaches to the A-frame. There seems to be quite a bit on mine. With the moldboard laying face down on the floor, and the A-frame facing straight up, I can move the A-frame back & forth about 2 inches at the top. Is that too much? Wondering if I should install a bushing in the A-frame hole, which appears to be where most of the movement of the 5/8 pivot bolt is at. Thanks for any input!

Bill

 

[finnegan]

the pivot bolt or (king) bolt is probably worn out replace with new one and crank it down good and tight,don't forget to neverseize the threads, you might need to get it apart someday...

 

[blades]

Acutally, the bolt seems to have practically no wear on it. The majority of the slop is in the pivot hole in the A-frame.

 

[finnegan]

see if you can put alarger bolt in it..

 

[sam c]

don`t take out all the play, i did that years ago thinking i was doing some great preventive maint. but it did more harm than good! the blade wouldn`t follow the contour of the road and when fully angled the the close side didn`t touch the ground because of the angle of the a frame.

 

[Chuck Smith]

I have been trying to come up with a way to use a tapered wheel bearing....

The problem is that the king bolt, is "grade 5" which is a harder steel than the steel plate it goes through. So that is why the steel wears before the bolt. I have even pondered using a roller bearing from a piston wrist pin. It could slip over the bolt, and would roll on the shoulder of the bolt, and the steel. The problem is a sleeve would be needed made of hardened steel. Rolling on the "layers" of steel it passes through would not work well or last long.

There is still so much room for improvement on all plows. Even the trip mechanism on other plows use no bushings, just "steel on steel".

Lou has installed bushings on his plow set up.

Hey Lou, how are the modifications you made to your plow holding up?

~Chuck

 

[cwlo]

Chuck,

I am very skeptical a bearing would hold up to that sort of punishment. Especially since the force transmitted to it would be consistently to the back 1/3 of the bearing, with the front of the bearing getting little pressure unless back dragging. I'd be curious to hear your reasoning, as I'm sure you've thought it out. If it did work, it would sure be a smooth working plow!

 

[blades]

Great input, guys. Thanks. I like the bearing idea, but it is such a nasty application and environment for precision components. Sam c has a good point regarding too close of a fit, as well.
When I took the 5/8 king-bolt out, I found the bore of the a-frame to be nearly 3/4 dia. at the top & bottom, and about 11/16 at the center. Anyway, I reamed out the hole to .750, but the only problem now is that the worn hole was not perpendicular to the frame (the reamer, of course, followed the worn hole, because I used a hand drill), causing a crooked assembly when I put in a 3/4 bolt. Now, I am considering setting up the frame on a Bridgeport, and putting in a nice, perpendicular 7/8 dia. hole for a bushing. Any error in the 2.75" long bore of the A-frame shows up big-time across the 6.5' blade.

 

[slplow]

2 inches is not that bad, when it gets more like 3.5 to 4 inches i would put a new a frame on it for only $180.