How to Put Larger Wheels On Your Garden Tiller

Before and after wheel retrofit

Most garden tillers are fair pieces of equipment but there at least one issue with one of the Troybilt models. This problem is not unique to Troybilt and can be found on tillers from other manufacturers. The "Bronco" model tiller as manufactured by the Troybilt company, has wheels that are entirely too small. The very small diameter and width of the tire/wheel assembly gives practically no traction or pull through the soil being tilled. The fix described here is for the Troybilt Bronco model, but can be similarly applied to other garden tillers with wheels that are too small to perform well. The wheels that come on this tiller are about 9.75 inches in diameter and 2.5 inches in width. They are solid rubber tires with a steel rim that has a 3/4 inch diameter bore for the axle. The TTB distance (through the bore dimension) on existing wheels is 2.5 inches. The accompanying photographs and text describe the retrofit of a larger tire/wheel assembly so that the tiller will operate more efficiently and do a better job of pulling itself through loose soil. The replacement wheels in this instance are tubeless pneumatic and are about 13.75 inches outside diameter and 4.75 inches wide with a TTB dimension of 4 inches. After the retrofit the tiller performs more nearly as it should have from the factory.

Things You'll Need

• 2 - tire/wheel assemblies that are pneumatic type (air filled tubeless or tube type) and that are larger in diameter and in width that the ones that are being replaced. Make sure that the bore size of
• Electric or battery powered drill
• A drill bit the same size of the pin holes in the axles
• Small ball peen or other hammer
• Center punch
• Safety glasses

Instructions

1. 

   Prop one side of the tiller up on a block so that one of the existing tire/wheel assemblies can be removed. After removing the existing wheel, place a new wheel on the axle. Now look at the holes in the hubs of the new wheels as opposed to the pin holes in the axle. The new wheel hub should fit on the axle so that most of the wheel hub length (distance through the bore of the new wheel hub) is on the axle. You can reverse the wheel if need be so that the valve stem is on the inside.

2. 

   If you do not like the position of the new wheel ( that is, if it is too far in or too far out on the axle) then position where you want and mark the position of the pin hole. Remove the wheel, center punch the position of the new required pin hole and drill through the axle. Replace the new wheel and make sure that the connecting pin will go through both the wheel hub and the axle. Place the keeper pin or cotter pin through the hole in the keeper pin.

3. 

   Repeat steps one and two for the other wheel. The tiller should perform much better than with the cheapskate wheels that came attached!

Tips & Warnings

• Since the new wheels may be larger in diameter than the old ones the tiller will be traveling at a greater fpm speed (feet per minute) than with the old tires. Just run in a lower gear or at a slower engine speed if you want a slower traverse speed.

• If possible when determining the location of the new tire/wheel assemblies, increase the inside to inside dimension of them. That is, set them out a little further out on the axles. This will aid in clearing roots, vines and other ground trash that must be occasionally removed.

• Disconnect the spark plug wire before beginning the work to avoid any chance of the engine starting while wheels are swapped.