18.4-34 Tractor Tires

Buying 18.4-34 tractor tires

18.4-34 is a rear size found on many utility and row-crop tractors, including a lot of older machines that are still working hard. It has the same 18.4-inch (about 467 mm) width as the popular 18.4-38 but fits a 34-inch wheel, so the tire is shorter overall. The two are not interchangeable without changing wheels.

For a radial, look for 18.4R34, also listed as 460/85R34. Many owners of older tractors stay with bias in this size because it costs less and the stiff sidewall suits loader work. If the tractor does long days of field work, a radial usually lasts longer and slips less. Our radial vs bias guide covers the trade-off.

What to check

• Rim diameter: read the size on the sidewall. 18.4-34 and 18.4-38 are easy to confuse on a worn tire.
• Loader use: a front-end loader adds weight to the tractor, so match or exceed your current ply rating.
• Liquid ballast: tell us if your tires are filled, so we can plan mounting and shipping.
• Used tires: ask for the tread depth, the date code and photos of any repairs.

Send the quantity and whether you want new or used, and we will quote with shipping to your location.

What do 18.4-34 tires cost on our site?

We list 12 models in 18.4-34. 10 have a listed price, from $190 (Ozka KNK50) to $1,569 (Galaxy Earth-Pro R-1) per tire, with a median of $855. Prices are per tire in US dollars and change with stock and season.

How tall is the 18.4-34 tire?

The nominal overall diameter is about 65.3 in (1,658 mm), which gives a rolling circumference near 205 in (5,209 mm). That figure is an estimate that assumes an 85% aspect ratio, the usual rule for old inch sizes. Real tires vary by make and load, so treat it as a guide and use the tire diameter calculator or the lead-lag calculator before you change size on a front-wheel-assist tractor.

Is 18.4-34 a radial or a bias tire?

It is a bias-ply size. The dash in the size marks bias construction, which costs less and has stiffer sidewalls. See the radial vs bias guide.