Garden Tractor Tire Spacer

thingiverse

This is quite an unusual project to embark on, I admit. A while ago, I swapped my garden tractor's tires from turf tires to lug tires. Initially, I just installed the new tires on the original rims but was not entirely satisfied with them. So, I decided that I needed a wider wheelbase for enhanced stability. I attempted to find spacers commercially, but there wasn't anything that fit directly, and what could be adapted were far too expensive and not locally available. Then, I thought about machining some out of aluminum plate or fabricating weldments (I have access to machine tools). However, I decided to try printing something first. **Some important notes-** Firstly, this is specific to AYP/Craftsman style garden tractors and others using the typical 4.5" bolt circle 5 bolt mount as shown. It may fit other brands because there's a lot of commonality in the industry, but I'm not certain. And it must use the same center hub diameter as the AYP/Craftsman tractors do. This is because the **hub** centers the wheel, **not** the bolts. Secondly, you should print the test ring first to check for material shrinkage and scaling against the hub diameter of the tractor axle. Change the scale in your slicer accordingly to achieve about a 0.010" diameter gap against your hub. Then use that scale for the actual spacer prints, of course. Thirdly, fair warning, this is a very lengthy print. It will take 4-6 hours to print one or even longer depending on your particular printer. Do NOT skimp on the fill percentage to speed it up; the final parts need to be as close to 100% solid as you can manage. **How to print and use them-** Print the test ring to get the proper size, which will save you from having to adjust the bore or nose post-print. It's highly advisable to check for material shrinkage effects if nothing else. Then print the spacers using the scale you determined with the test ring. Print with the highest percentage of fill your printer can handle. Clean up the support material in the side holes and ream out the bolt holes if necessary using a drill. For the spacer as it is designed, the wheels are moved outwards by 2", so the original lug bolts will not work. You'll need to purchase 7/16"-14 x 2-1/2" long bolts and hardened steel washers. Note that I only had longer ones on hand, so they show a lot of thread in the photos. If you scale the spacer thickness differently, adjust the length of the bolts accordingly. Mount the spacer and wheel to the axle using the new bolts with the washers between the bolt heads and the wheel. Tighten in a star pattern using several passes. Don't torque the bolts like crazy as you might be tempted to do if the spacer was made with metal. After a few hours, re-torque them again using a star pattern and making several passes. Check them after a few uses and then again after a few weeks. I can tell you that they make a **huge** difference in the "feel" of the tractor. It rides over bumps much more comfortably now because there's less side-to-side jostling. Also, the tractor is now more stable when traveling across hill sides and slopes due to the wider wheelbase. As of late December 2019 so far, I have had absolutely **no** problems with the pair I made. They did stabilize so that I haven't had to re-tighten them recently, even with the colder weather. I hope you will enjoy using them as well. Please pardon the grass clippings in the lug tire photos; our tractor gets used a lot.