Crankshaft Manufacturer & Supplier – EMD 645 & 710 Parts

Overview

The 645 and 710 are direct evolutions of EMD's earlier 567 engine — bore was increased for the 645, and bore and stroke both increased for the 710, all without changing the external engine envelope. The crankshaft is what absorbs that extra load: it carries the main and rod journals plus the counterweights needed to keep a bigger, harder-working engine balanced.

How It Works in the Engine

Counterweights offset the reciprocating mass of the pistons and connecting rods as the crank spins, cutting the side-load the main bearing journals would otherwise see and reducing vibration transmitted through the block. A crankshaft that's out of balance or out of tolerance doesn't just wear itself — it accelerates main bearing wear across the whole engine.

Signs You Need a Replacement

• Journal scoring, scuffing, or out-of-round wear
• Main or rod bearing clearance growing faster than expected
• Unusual low-frequency vibration that tracks with engine speed
• Discoloration or heat marks on a journal, pointing to a bearing that ran dry

Why Source This From Apex International

Journal and counterweight dimensions are checked against EMD/DLW reference specs and the shaft is balanced before it leaves our facility, so bearing life downstream isn't shortened by a crank that was close enough instead of correct.