---
kind: "section"
citation: "49 C.F.R. § 229.73"
title: "49"
number: "229.73"
heading: "Wheel sets."
url: "https://uscodex.org/cfr/49/229.73"
---

# §229.73. Wheel sets.

- (a) The variation in the circumference of wheels on the same axle may not exceed 1/4 inch (two tape sizes) when applied or turned.
- (b) The maximum variation in the diameter between any two wheel sets in a three-powered-axle truck may not exceed 3/4 inch, except that when shims are used at the journal box springs to compensate for wheel diameter variation, the maximum variation may not exceed 1 1/4 inch. The maximum variation in the diameter between any two wheel sets on different trucks on a locomotive that has three-powered-axle trucks may not exceed 1 1/4 inch. The diameter of a wheel set is the average diameter of the two wheels on an axle.
- (c) On standard gauge locomotives, the distance between the inside gauge of the flanges on non-wide flange wheels may not be less than 53 inches or more than 53 1/2 inches. The distance between the inside gauge of the flanges on wide flange wheels may not be less than 53 inches or more than 53 1/4 inches.
- (d) The distance back to back of flanges of wheels mounted on the same axle shall not vary more than 1/4 inch.

## Notes

### Authority

Authority: 49 U.S.C. 20103, 20107, 20133, 20137-38, 20143, 20168, 20701-03, 21301-02, 21304; 28 U.S.C. 2461 note; and 49 CFR 1.89.

### Source

Source: 45 FR 21109, Mar. 31, 1980, unless otherwise noted.