Adjusting tires for plowing

Just bought a three 14 jd plow.Is there a way to figure out the right side tire spacing measurment from center of tractor

I always ran the 3 bottoms at 76 and it worked just fine.

Allan

yes,center of draft would be 1/4 of 1 bottom (3.5 inches) left of center,of full width cut on your plow . so figure 3x14=42"divided by 2 =21"plus 3.5=24.5" from center to INSIDE of left( or right depending on which way your plow throws) tire. that should put you really close. other tire can be set most anywhere,unless you using a rollover plow then it will have to be the same. At least according to jds old books thats the formula. it will vary slightly with the width of your rear tires as far as the centerline on tires. most of the time they are figured with stock width tires,so if you use bigger you have to adjust the width some. A disc plow doesnt measure left of center.center of draft on those are 1/2 full width of cut.

I presume you're talking about a pull type plow like a #55 or #555 trailer plow. I've found that the draft point of these plows is about 4 inches right of the center bottom point which makes it about 24 or 25 inches from the furrow wall where the right tire of the pulling tractor would be runnning against. So I space the right wheel so the right tire inside wall is about 27 inches from centerline of the tractor allowing for the tilt of the wheel when it's in the furrow and the "sqush" of the tire which in my case is a 14.9-38 inflated to 12 lbs. on my John Deere G tractor. This seems to put the furrow wheel of the plow about 2-3 inches from the furrow wall and the front bottom cuts pretty close to 14 inches most of the time.

According to my manual for a F135 3X14 center of tractor to inside of the right rear is 26". I have my tractor set a 68" center to center and that seem to work well.

You did not state if the plow is Mounted or "Pull-Type"..

For a "Pull-Type" plow..most farmers set the hitch of the Plow to be correct for use with the Same wheel width required for Cultivating Corn..
On our JD "B" tractors, that is around 29 or 30" from Center-line..and works for either 2 or 3 Bottom 14" Pull-Type Plows..
The Plow Hitch has available adjustments to allow plenty "Off-Hitching" and maintain a straight "Line of Draft" on the Plow..
That would be with 11x38" tires..(12.4x38 now)..
A Mounted plow will require a narrower rear tire setting, to match with the plow..

Ron..

You did not state if the plow is Mounted or "Pull-Type"..

For a "Pull-Type" plow..most farmers set the hitch of the Plow to be correct for use with the Same wheel width required for Cultivating Corn..
On our JD "B" tractors, that is around 29 or 30" from Center-line..and works for either 2 or 3 Bottom 14" Pull-Type Plows..
The Plow Hitch has available adjustments to allow plenty "Off-Hitching" and maintain a straight "Line of Draft" on the Plow..
That would be with 11x38" tires..(12.4x38 now)..
A Mounted plow will require a narrower rear tire setting, to match with the plow..

Ron..

Only ones ever set plow to tractor tread width was a Ford 2N with 12" mounted plow and that was also standard width for everything except cultivating and the 5000 Ford with a 4-14" semi mounted plow. All others were just whatever tread width the tractor was on for other uses or as was the Case with the Deere AR the tread was fixed and just set the hitch acording. Using that formula with a small plow you could not set the wheels in close enough to get it and if you could have the tractor would have rolled over on its side as soon as a wheel dropped in the ground.

I just measure from the center of the hitch on the plow to the outside of the front share.
Then add in half the tire width and call it good. Probably did it wrong all these years.

suggest you watch for one of the old school books put out by john deere for years and years, that formula is right out of john deeres own books. if it were wrong,youd have thought they would have killed off all their customers after the sixty years or so they published that info. you can off hitch,theory and measurements the same.pulling a small plow with a big tractor your correct in that you cant set tires close enough,so then you would have to off hitch. works on most plows of any brand.if you would care to check,i bet youll not find its off much when your pulling your own. main trouble with off hitching is your throwing draft to one side of tractor. closer you can keep to centerline the more even draft is so you get less slippage on tires. saves having to have weight a lot of time if you pull down centerline of tractor.

The closer the size of the plow is to the capacity of the tractor, the more important getting it as close to "right" as possible is.

Try sliding the wheels all the way out on a Farmall M and "off-hitching" a 3-14 plow. You'll be riding the left brake all day trying to keep the tractor in the furrow and going straight.

This all is hardly an exact science, though. There is a range where the side draft will be unnoticeable to tolerable. Off-hitching a few inches one way or the other, not a big deal.

Centre of pull on the tractor? Are you using the centre line of the tractor chassis? Or measuring halfway between the tires ? There can be several inches difference.

centerline of the tractor,is what jd says.

centerline of the tractor chassis,is what jd says.

I would assume the factory directions assume the read wheels are an equal distance from the tractor centreline.
To run a 2x12 frame plough with 14" bottoms mounted on my Dubuque Deere two cylinder. The plough is shifted to the max on it"s lower hitch bar . Plus the tractor right wheel needs to be racked in about 3" from minimum. Now that is a W row crop utility chassis with the optional short axles. Wheels are dished out to wide side. I leave the left wheel out to max width on the axle. Steers straighter that way.
Not a whole lot of dirt turned over left of the tractor"s centreline with that narrow of a plough.
Plough does track straight behind the tractor without either lower link pulling on the sway chains.

I have those and also I know John Deere did build the GP wide tread with an 80" wheel tread and it worked just fine. Also the wide tread Farmall Regular, F20 & F30, so if it was that much of a problem then they could have not done any plowing with them. And these are the same tractors that if you followed those directions and could have set the wheels in as far as those directions call for it would fall over.

had a jd "A" when i started farming on my own that had the tires set all the way in and the axles cut off, it never fell over. ran a f-20 for years as a kid that the wheels were set as far in as possible , never turned it over. used a wc,a wd, and a wd45. all of those were set as far in as possible to go on a trailer ,never turned them over. several others ,but i guess ive been lucky.

you can offset,no question.. BUT..if your dropping one tire in the furrow,plow will be offset the EXACT same amount,in other words if you shift furrow tire to right ,you move plow to right.when you get it setup and plowing correctly check your measurement,still the exact same distance to in side of tire. measurement tells you what it should be,difference between that and you tire width gives you the offset. very very simple to set one this way, saves all sort of time in the field adjusting back and forth trying to get it to work right. tractor simply pulls better with less slippage if center of draft is in line with center of pull.because draft is equal on both tires,doesnt "HAVE" to be equal,but youll get less tire slippage and have to use less weight to get your tires to hold. basically just a simple thing called leverage,one tire slips,other doesnt, tractor tries to turn,same as stepping on one brake. the more you offset,worse the problem becomes. NOW you CAN up to a point adjust the hitch clevis on your plow to offset this,BUT BUT BUT your NOT in any way steering the plow as many folks here claim!!!!what you really are adjusting is the WIDTH of cut, which goes right back to the formula where you start with overall width of cut. when you change the width of cut,you simply shift center of draft.

What is so difficult to understand about there being DIFFERENT "formulas" for different plows?

1-2 bottom plows are too narrow for "the formula."

3-4 and maybe 5 bottom plows are what "the formula" was designed for.

6+ bottoms is on-land so "the formula" does not apply.

What's important is that the line of draft follows a straight line from the center of draft on the plow, up the drawbar, through the clevis pin, and to the drawbar attachment point on the tractor.

in your case,if i am understanding correctly you have one tire in all the way ,other OUT all the way.off tire can be set anywhere what matters is the furrow wheel. measure the distance you have this plow set to inside of furrow wheel and youll find that t matches the formula quite closley. in Your particular case, your using the extra tire width on the land side to make up for slippage on the furrow side.your tractor with tire set out on the land side simply moves farther with each turn around the center off setting side pull.which is 100% fine.if thats the way you like it. your simply making up tire slippage with distance on the otherside. no problem there.BUT heres the rub.tires slippage causes undue wear,higher fuel comsumtion etc etc simply because if tire is spinning it is not pulling. a more effecient use of your tractors actual power could be had if you minumized slippage instead of offsetting it. by adjusting plow correctly,narrowing or widening width of cut the proper amount you could minumize slippage ,gain actual pulling power,save fuel( or at least get all the work you could out of each gallon) reduce tire wear,reduce wear overall on your trcator because it wouldnt be fighting with a constantly varying load, and alot of other things. basically youve set your TRACTOR to the plow, try setting your plow to the tractor and youll find it works much easier.formula simply tells you how much distance you need to furrow wheel,and if you cant achieve that,how much offset is needed. thats ALL. and you will find even on yours its very close to right.minumizing draft for your plows condition ,local soil conditions etc means you need to tweak the adjustments slightly.to do that you need to know HOW and what to adjust on YOUR plow and tractor,to minimimze draft.that can change even over the course of a day as your field condition changes or as your shares wear etc.formula is a starting point,it wont vary much either way.

I think we are both saying. If the plough, hitch and tractor are set correctly.
The plough will track straight. All the plough's moldboards will be taking a full cut. There is no lateral/side load on the drawbar or three point lower links. The tractor will steer it's self straight if you take your hand from the wheel. Each drive tire will be applying the same "pull".
Don't see that very often. A lot of fuel, tires and production lost due to mal-adjusted ploughs.

yep,lots of way of hitching one ,but hitching is just the beginning.