49 CFR § 229.63 - Lateral motion.

---
identifier: "/us/cfr/t49/s229.63"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "49 CFR § 229.63 - Lateral motion."
title_number: 49
title_name: "Transportation"
section_number: "229.63"
section_name: "Lateral motion."
chapter_name: "FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION"
part_number: "229"
part_name: "RAILROAD LOCOMOTIVE SAFETY STANDARDS"
positive_law: false
currency: "2026-03-24"
last_updated: "2026-03-24"
format_version: "1.1.0"
generator: "[email protected]"
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."
regulatory_source: "45 FR 21109, Mar. 31, 1980, unless otherwise noted."
cfr_part: "229"
---


# 229.63 Lateral motion.

(a) Except as provided in paragraph (b), the total uncontrolled lateral motion between the hubs of the wheels and boxes, between boxes and pedestals or both, on any pair of wheels may not exceed 1 inch on non-powered axles and friction bearing powered axles, or 
3/4 inch on all other powered axles.

(b) The total uncontrolled lateral motion may not exceed 1
1/4 inches on the center axle of three-axle trucks.