Description

Enhance your fleet’s wheel-end durability with the Stemco 450‑4973 Pro‑Torq® keeper nut, designed for drive axles in heavy-duty trucks and trailers. This single-nut locking system ensures ultra-precise bearing preload, reducing maintenance variability and extending bearing, seal, and tire life.

Technical Specifications

• Thread Size: 3 1/4″ – 12 UNC

• Outer Bearing Cone/Cup Compatible With: 580 / 572 (also noted as HM518445 / HM518410)

• Tool Socket Required: 4 3/8″, 8‑point (OTC #1917)

• Application Range: Drive axles—supports 34,000 to 46,000 lb Eaton, Meritor, Dana, Navistar, and up to 50,000 lb Mack

Cross‑Reference Part Numbers

This keeper nut is interchangeable with:

• Stemco: 449‑4973, STE450‑4973, STM4504973

• Meritor: R009528

• Ceromet: K3250

• OEM Applications: Volvo 21052655 & 8084235; Eaton E‑2303; Ford E4HS‑4255‑AA; Navistar 1607744C1; Euclid E‑2303/E‑2466; Leland L-13 series; Batco 06‑411; Transit TP‑1978; and more

Why Choose Stemco 450‑4973?

• Precise Preload Control: Achieves bearing end-play down to 0.001″ increments—proven to maintain adjustment within the ideal 0.001″–0.003″ range

• Single‑Nut Security: Removes complexity of dual-nut systems—no jamming, no over-tightening, pure consistency

• Robust Construction: Featuring induction-hardened bearing contact surfaces and a durable spring-steel keeper designed for rugged operation

• Service-Friendly: Includes visible torque-and-back-off markings, locks at every 0.001″, and installs easily using standard OTC sockets

Installation & Torque Procedure (for 450‑4973)

Follow the Pro‑Torq® 2-1-1 method for consistent preload:

1. Tighten to 200 ft·lb, rotate hub, repeat two more times.

2. Back off ¼ turn (one face mark)

3. Tighten to 100 ft·lb, rotate hub, repeat, then back off ¼ turn and install keeper .

4. Final bearing end play should register 0.001″–0.003″.