70 series 4 bottom plow

Might have a manual. Will check tomorrow

Will try to post the short video of my brothers newly restored 190XT pulling it.

With the three point hitch, the lift arms on the tractor set the plow left/right tilt and you want it level with the right side tractors tires in the previous furrow. One way of setting is to put the left wheels on blocks the depth you plan to plow while on level ground and level the plow. The top link usually sets the fore to aft tilt so to get the rear bottom to plow the same as the front bottom the top link needs to be lengthened. Some plows have an adjustable link from the hitch to the back of the plow frame for that adjustment.

Gerald J.

Gerald, a semi mount plow wouldn't have a top link.

I agree with both Mack on leveling, and about the shears.

The plow frames are the same for the different hitches. Only the hitches change.

If it has a top link its a three point hitch, not a semi mount and attaching the top link and lengthening it should put the rear bottom into the ground. Alternatively a weight will do that using the trailing lift wheel and the gauge wheel to set the depth.

There are vendors on this forum with plow shears but first you have to identify the plow bottoms. There is an extensive article AC Plows Parts 101 over on the Knowledge Forum that gets into details and links some downloadable plow frame and plow bottoms parts books. You need to find a part number on the moldboard or share or maybe the frog and then in the plow bottoms book you can identify the bottom. And can identify what the part numbers were for shares and other wear parts. Coulters and landsides were practically universal. And AC offered dozens of plow bottoms in 12 to 18" in the 70 family era that fit every plow frame they made. A couple of the latest bottoms still have parts made by aftermarket plow parts makers.

Gerald J.

I don't intend to argue with Gerald....he may be right. But it surely seems to me, that if you have a 3 point mounted plow, and not a semi mount, your top link would hold the plow up, not "shove" it down. Yes, the longer the link, the more the back of the plow could go in the ground, but with no link at all, the only thing holding it up would be the trailing wheel, since a plow should be wanting to dig in. This is confusing to me. I've never had an Allis mounted plow, but the mounted plows I've had, the trailing wheel was fixed since the 3 pt hitch lifted the whole plow. The gauge wheel is there as just that, a gauge, you don't necessarily have to have it rolling on the ground, just skimming the ground, or even on the frame. The gauge wheel doesn't set or control the depth, it shows you when you get there. IMO. If you have an attachment point for a top link, AND it IS a semi mount plow, then the plow hitch must pivot on it's own? I'm not Allis plow expert, but I do own a deere plow made like that, but much much newer than any Allis plow, it's called a "double pivot hitch". So back to the trailing wheel, it has to be what's holding you up...Is the cylinder travel allowing full adjustment? Is there a stop screw holding you up? You say, "front is down to the coulter axle, but the rear isn't riding on the gauge wheel". How deep is the last bottom plowing? Check the height of the dead furrow wall....and let us know! Bad shears can make it skid across the ground, but if it's like 5 inches deep or something and you want it deeper, there's some other adjustment you need to make..

Edited by Tbone95 - 13 Apr 2017 at 8:46am

That makes some sense too DougS. I guess it depends on how short "short" is and how long "long" is. I could see it both ways. It seems that could change the "suck", not so much the depth, as lowering the 2 arms still puts the front bottom at a depth relative to the tractor, and if you had it "way too short", you could be pulling the tail out of the ground so to speak. Still, if this is a semi mount, the only thing holding it up at the rear of the plow only has to be something in the tail wheel?

Edited by Tbone95 - 13 Apr 2017 at 9:46am

Maybe try lowering the tail wheel, then putting the hydraulics in neutral rather than float?

I'm trying to post some pictures shortly. I have watched videos with tractors using these plows and dont see any using a top link. Not sure why the top link attaching point is there. It appears factory.

If Matt doesn't have manual I have one. Operating instructions 70 and 80 series 4 and 5 bottom plow (semi mounted) form TM-291A. Have one for a no.74 4-bottom also form TM-160.

The shares will make it act all sorts of weird. Start there. Have any part numbers

Edited by Mikez - 15 Apr 2017 at 8:28pm

Look on the back of the moldboards for any numbers stamped into it. If no luck un bolt a share to see if any stamped on back of them, if not unbolt shine and look. There should be part numbers stamped on backs of parts, then we can look in plow bottoms parts book and see what no. bottom you have. Yes I will sell you a manual but lets see what you find to make sure have the right modal plow.

Finally got some pictures on the forum! Hope this helps in identifing my plow. The hydraulic hose burst so until I get a new one, I can't fully raise the plow to pull a share to look for numbers. Until then I would just to like to verify that this is what I believe is a series 70 semi mount. Once that has been established I can get a operators manual. Some good ideas from all of you.