A Simple "Weigh" to Add Weight to Your Tractor

We often need more ballast (weight) in garden tractors for a number of reasons—for better traction, or to counter balance a heavy attachment, etc.

You can buy or make weights that fit inside your wheels, or add "suitcase" style weights to the front or rear of your tractor.  These weights can be expensive, though.  Used 12” Wheel weights can cost $100 plus per set, not to mention shipping costs.

As most of you know, farmers often use liquid-filled tires to add weight to their tractors--mainly in the rear tires.  Water alone weighs about 8 lbs per gallon. Add a dissolved salt or similar mineral to the water makes it weigh more, thus adding more weight in the same volume.

A major drawback of this method is that the salts used as ballast in the tires are very corrosive to the metal wheel. The process also requires taking the wheels or the whole tractor to a dealer or repair shop to get the work done.

A simple way to add weight to your tractor is to put in your own water ballast.  However, to avoid rusting your wheels and freezing in winter, some type of antifreeze needs to be added.

Regular ethylene glycol (engine antifreeze) isn't a good choice since it's highly toxic. It's also pretty pretty expensive at $8-12 a gallon. (Just a standard 4.80/4 x '8" tire will hold a gallon or more.) And, if you need to empty your ballast, you can't just pour it out on the ground...

I was in Wally World a few weeks ago, and noticed they had discounted their Prestone RV Antifreeze to $3.49 a gallon.  Suddenly I had a thought (yes, though rare, I do get them sometimes...),

"Why don't I just mix RV Antifreeze and water for ballast in my tractor tires!!!"

I knew that RV antifreeze has low-toxicity, and also has additives that help preserve metal components and is compatible with rubbers and plastics.

So, I proceeded to buy 5 gallons of it--not being sure how much I would need.

However, having used up all my original thoughts for that week, it was a couple weeks before I came up with a way to get the mixture INTO the tire.

The standard Schrader valve stem has a .305 O.D., and a .209 I.D.  The thread is also special, so you can't readily find fittings for them so you can pump the liquid into the tire.

However, a 1/4" I.D. rubber hose makes a pretty good fit over the threaded part of the valve stem, and also fits pretty snugly on one of the tapered nipples that on the caps on quart bottles of 80W90 gear lube, etc.

With all this in mind, this is how I filled the front tires of my Sears GT18:

1. Get a one quart spray bottle and remove the sprayer.  All the ones I looked at had the same thread as the cap from the gear lube bottle, so it will screw down securely on it. Cut the end off the nipple to open it, but don't cut too much as you need enough left for the hose to grip it tightly.

2. Cut off at least 6 inches from a piece of 1/4" ID hose--more if you're doing it on the tractor. I've found that rubber vacuum tubing works best--it's pliable enough to slip over the valve step and nipple, and strong enough to grip it tightly.

Here's my setup:



The first time I did this, I left the wheel on the tractor and just rotated it until the valve stem was at the top.  6 Inches of hose was a little short--I had to lay on my side to put it in the wheel, especially since the valve stems on the Sears tractors are on the inside of the wheel.

The Prestone bottle says it's RV antifreeze will protect against bursting down to -50 degees F, though the mixture starts getting slushy at about 0 degrees F.  We sometimes get below 0 here in Utah, but I didn't anticpate needing -50 protection, so I mixed the antifreeze with tap water in a 5 to 3 ratio of antifreeze to water.

3. I wasn't sure how much mixture I would need, so I pre-mixed the two the first time I did it.  As it turns out, each 15 x 6.50-8 tire and wheel will hold over 2 gallons!!  You want to leave some space for air so you can inflate the tire, and I found that 2 gallons does the trick--5 quarts of antifreeze and 3 quarts of water.

4. If you leave the tire on the tractor, just quit filling when the liquid starts to run out of the valve stem.  If you remove the tire and lay it flat, prop up the side opposite the valve stem about 1 1/2 inches.  This will insure there's room for air in the tire.

5. To fill the tire, remove the Schrader valve from the valve stem and slip the hose over it.  If the hose is real tight, you can screw it onto the stem--this will ensure a good seal.  Fill up the quart bottle with liquid, put the lid on snugly and slip the hose over the end of the nipple.



Invert the bottle and squeeze.  Since you're filling a confined space, you will need to let off periodically to allow the displace air to gurgle up through the valve stem and hose and fill the top of the bottle.*  The process takes a little time, but works pretty well.  I have found that using warm water makes the bottle easier to squeeze and less likely to split or crack.

It does take a little time to do just  a front wheel--about 10 minutes. A rear wheel will be substantially longer.

Even then, this process is much cheaper and simpler than using steel weights.

On my Sears GT-18, it added over 30 lbs to the front of the tractor.  I don't know how much is needed for the rear as the tires already have liquid ballast in them.

TOTAL COST: Under $10.

*One alternative that would allow faster filling would be to break the tire from the wheel, and drill a 3/8" diameter hole for a new valve stem--I'd put it at the same location as the original valve stem, but on the opposite side of the wheel.

With this set up, you would fill it tire with the valve stems in the 12 o'clock position.  Take the Schrader valve out of each valve stem and attach the hose to one of them.  The valve stem without the hose allows the air to escape--thus greatly speeding up the filling process.