Adapting a 3pt drawbar to a generic Quick Hitch

[Threepoint]

I keep a Harbor Freight cat 1 quick hitch on each of my loader tractors. I wanted to use an old "3pt Drawbar" I've had in the barn for years to pull a manure spreader and a log splitter, and to move trailers around, without first removing the QH. A traditional "drawbar lock" (see, e.g. https://qualityfarmsupply.com/product/HITCH-ampersand-LINKAGE/DRAWBARS/873-dash-DB4130) won't work because the QH frame prevents it from locking over the lower lift arm. Without a lock of some sort, there is nothing to prevent the drawbar from rolling over in the QH's lower lift arm hooks.

I've seen other solutions on TBN, but here's mine. It will work on any of the generic QHs, either cat 1 or cat 2, although some of the measurements might need adjustment, and probably on the branded models as well. No welding is involved. I made a pair of DIY drawbar locks from scrap 3/16" steel plate. See pics below. Rather than lock directly to the lower lift arms, they are held in place by the QH's own lower link pins, sandwiching between the hairpin clip and the gussets of QH frame. 3/16" plate is thin enough to do this without modifying or changing out the QH link pins, yet plenty strong as a pair to do the job. NB: That job is only to keep the drawbar from rolling over. Neither they nor the traditional single lock are intended to withstand the inline towing forces on the drawbar. The QH lift hooks (and link arms themselves) are for that. Thus it is important that the rectangular cutouts in the plate be large enough not to interfere with that.

The plate I used is scrap I had on hand. Dimensions for each lock are 9" x 2-3/4" x 3/16". The rectangular cutout is 3" x 1-1/8", cut with a hand-held jig saw with a bimetal blade after drilling starter holes in each corner. I left 3/4" of material between the cutout and the end of the plate. The bend in the plate is made 6-1/8" from the end. The 7/8" hole for the QH link pin is 7" on center from the end. I don't have a brake for my hydraulic press, so I made the bend by just clamping the plate in a vise and persuading it with a 4 lb drilling hammer. That's another reason not to use plate thicker than 3/16". In the pics, you'll also notice two unused 3/8" holes in each adaptor, which were already there in the scrap I used. They don't materially affect the strength of the adaptors.

If your QH is not a HF hitch, I suggest first cutting a prototype out of stiff cardboard to make sure the measurements don't need adjustment.

In order to keep the drawbar's fixed 7/8" lift pins from slopping around too much in the QH lower hooks, I added bushings cut from 1" galvanized plumbing pipe. They are 1-7/8" long. You can also buy commercial bushings for this, sold as "Cat 2-3" to bush up from 7/8" to 1-1/4".

Finally, and I can't stress this enough. When pulling with a 3pt drawbar, always keep it as low as possible! Pulling with it above the height of the tractor's frame-mounted drawbar dramatically increases the rotational forces around the tractor's center of gravity and risks a turnover.

 

[N2DFire]

Just be careful if anything you plan to tow uses the clevis style hitch instead of a ball hitch.

On even mildly hilly terrain your angle of approach/departure may be more than the "slop" in the clevis can accommodate and you'll end up bending something.

The ball style hitch is designed to allow for this kind of rotation, the draw bar & clevis hitch rely on the ability of the drawbar to rotate, which you have just eliminated.

Other than that, you do great work and I am jealous. :thumbsup:

 

[CobyRupert]

...also be careful when pulling trailers or a manure spreader that doesn't have sufficient tongue weight (example: manure spreader that's 1/2 unloaded, and all the weight is at the back).
Most 3pth's have no down force. When there's insufficient tongue weight, or negative tongue weight you might end up with some unexpected, undesirable, results. Especially if you're going downhill, or when backing up and trailer tires hit a rut or some resistance.

 

[Threepoint]

Just be careful if anything you plan to tow uses the clevis style hitch instead of a ball hitch.

On even mildly hilly terrain your angle of approach/departure may be more than the "slop" in the clevis can accommodate and you'll end up bending something.

The ball style hitch is designed to allow for this kind of rotation, the draw bar & clevis hitch rely on the ability of the drawbar to rotate, which you have just eliminated.

Other than that, you do great work and I am jealous. :thumbsup:

Thanks for the kind comments. You are absolutely right about the angle of approach/departure when pulling a clevis style hitch with a 3pt-style drawbar. If the terrain will exceed the combined "slop" that is designed into the clevis and the locks, then the drawbar should be left to rotate freely. I sized the rectangular cutouts to the same dimensions used for the two common styles of commercially-available locks (pics below) to allow for this issue. But the caution is equally valid with those as well when pulling a clevis hitch. The first style of commercially-available lock, at least what I have seen, uses 5/16" plate and is sold as a single lock. I used 3/16" plate because it's what I had, but have one on each end for added strength.



By contrast, the drawbar has to be locked, within the limits of the "slop", in order to use a ball mount on it to pull equipment with a ball-style hitch. Otherwise the ball may rotate right out of the coupler. Which is why I bought the commercial lock 25 yrs ago, long before I started using QHs.

 

[Threepoint]

...also be careful when pulling trailers or a manure spreader that doesn't have sufficient tongue weight (example: manure spreader that's 1/2 unloaded, and all the weight is at the back).
Most 3pth's have no down force. When there's insufficient tongue weight, or negative tongue weight you might end up with some unexpected, undesirable, results. Especially if you're going downhill, or when backing up and trailer tires hit a rut or some resistance.

Very good point. The 3pt drawbars are dangerous enough in and of themselves because of the opportunity for operator error in adjusting the height of the lower lift arms. Add to that the lack of downforce to restrict upper movement and they can be even more so. Good to think about before bouncing along at speed through a rutty field pulling a manure spreader.

 

[CobyRupert]

Come to think of it:
If the tongue weight on a manure spreader on a 3 pth cross-drawbar goes negative and lifts the 3pth, the cross draw bar will be stopped by the spreader’s pto shaft.

Shaft may have a wobble to it the next time you use it ...and probably won’t slide very well.

...and don’t raise the 3pth lever by mistake either.

 

[bcp]

The 3pt hitch was originally intended to be fastened down so it wouldn't lift when used for a trailer.

See the two adjustable stay straps that go from the top link mount to the drawbar ends.

A good photo about halfway down this page:

Drawbar Hitch - Yesterday's Tractors

Bruce

 

[Threepoint]

Come to think of it:
If the tongue weight on a manure spreader on a 3 pth cross-drawbar goes negative and lifts the 3pth, the cross draw bar will be stopped by the spreader’s pto shaft.

Shaft may have a wobble to it the next you use it though. ..and probably won’t slide very well.

...and don’t raise the 3pth lever by mistake either.

My manure spreader holds just 27 cubic ft and is chain driven by the wheel rotation. So no PTO shaft.

 

[Threepoint]

Bruce, good pic and link. Makes sense that it was done that way.