Grader Box mod -- Rod through the tube

[davel8257]

I have a 6ft Wallace brand Grader box which I've been using to grade a gravel parking lot. The crushed rock was very packed. I've had as many as 3 adults standing on the back adding weight with the knives fully extended downward the top link in the the shortest configuration possible.

After several hours, I noticed that 2 of the pin holders welded to the top of the square tube had cracked. Another few minutes and the pin holding the knife would have been free removing any downward force on those knives.

I touched up the holder with my wire welder. Those holders are not very heavy duty. I was thinking of a more heavy-duty solution -- such as welding some thick-wall tubing in their place. The 1/4" pins could be replaced with 5/8" pins as well.

Then I got to thinking -- why not drill holes in both sides of the box, through the side plate and run a 5/8" rod through the inside of the square tube? The side walls of the tube would then carry the downward force onto the knives. I found a good picture on the wallace Mfgr website of the grader box -- I've annotated the hole and rod location on one side in the attached picture.

Any thoughts?

 

[scrappy isb67]

i wouldn't, first off it is going to be difficult to get everything lined up to reinstall the pin inside the box. second there will be no support in the tube for the pin so it WILL bend. and finally if it DOES bend you are either gonna fight to get it out and/or back in.
IMHO, I would just beef up the tabs on top and call it good.

 

[troutsqueezer]

I've had as many as 3 adults standing on the back adding weight with the knives fully extended downward the top link in the the shortest configuration possible.

Any thoughts?

 

[MtnViewRanch]

While this can be done and is how the roll over box blades are done, I believe that you will end up doing something else after you do this. With the roll over boxes, you put the rod in and you are done with it until you need to actually change a ripper shank out if it breaks or bends. With what you are proposing, if you use your rippers very often, I think that hassling with that rod again and again and again would get old REAL QUICK. :mur:

Good luck

 

[joshuabardwell]

I've had as many as 3 adults standing on the back adding weight with the knives fully extended downward the top link in the the shortest configuration possible.

This may be part of your problem. Box blades are typically designed around their own weight. Heavier blades are made of thicker steel, to take the greater forces generated by the heavier box/larger tractor. When you add ballast to a box blade, you are often asking for a damaged blade, which appears to be what happened here.

 

[davel8257]

re:Scrappy -- good point. I was thinking that I'd locate the hole as close to the top, inside (ID) of the tube, so that the thick wall of the square tube would bear downward force. Another factor I was going to consider is stepping up from a 3/8" pin to 5/8" pin. The holes holes in the knives are slightly larger than 5/8" (I tried a pin that I had and it moves in/out freely). But -- a long bent rod could be really hard to remove and even hard to re-insert when I want to raise the knives and just use the back blade.

re: Joshua --> yes, I abused the box -- too much weight and traveling over hard-packed crushed stone driveway. Without the weight, the box just bounces around on top.

I think I'll re-visit my local welding shop and see what thick-wall tubing (square or round?) they have that I can use to weld on the top and stay with the original design. I think I might step up to 5/8" pin size which will still allow for easy insertion and removal.

 

[scrappy isb67]

re:Scrappy -- good point. I was thinking that I'd locate the hole as close to the top, inside (ID) of the tube, so that the thick wall of the square tube would bear downward force. Another factor I was going to consider is stepping up from a 3/8" pin to 5/8" pin. The holes holes in the knives are slightly larger than 5/8" (I tried a pin that I had and it moves in/out freely). But -- a long bent rod could be really hard to remove and even hard to re-insert when I want to raise the knives and just use the back blade.

Putting it in @ the top of the tube would work for the downward forces but just makes the upward forces even worse(I.E. when lifting the rippers out of the ground)

 

[Arc weld]

Just put heavier mounts on the top. I'd bet that the shanks are heat treated and you'd never drill them. If you did might weaken them though as they'd have less meat between the edges and the larger hole. If the shanks are at the lowest setting, is there one of the adjusting holes sticking out the bottom of the tubing? If so, make a block for each side to go up against the tubing and just use a pin through the shank to hold it in place.

 

[crazyal]

On my grading scraper they have pieces of flat steel inside the cross tube. When the ripper teeth get force on them they push against the flat steel. The 5/8" pins never have any real force on them.

 

[Xfaxman]

On my grading scraper they have pieces of flat steel inside the cross tube. When the ripper teeth get force on them they push against the flat steel. The 5/8" pins never have any real force on them.

His is different, the hole takes all the force.


This is your style, the notches can be on the front or back edge.