Battery Keeps Dying? 40A Alternator for Kubota, Case & Grasshopper

Author : Danny walker | Published On : 05 Oct 2026

If your Kubota-powered machine keeps killing its battery, check the alternator first. The Alternator Fits Case Grasshopper Kubota 100211-4520 16231-64010 16231-64011 is a brand-new aftermarket 12V, 40A replacement for Case, Grasshopper, Gravely and Kubota equipment.

What it does: The alternator powers your lights, gauges and controls while the engine runs, and recharges the battery. Signs of failure include a battery that keeps going flat, dim lights, hard starting, a charge warning light, or a machine that dies when the battery drains.

Test first: A weak battery, slipping belt or corroded terminal can look the same. A charged battery reads about 12.6V, so charge it if it's below 12.4V. With the engine running, expect roughly 13.5–14.8V. Low voltage after checking the belt and connections points to the alternator, while a reading above 14.8V suggests a faulty regulator. Never disconnect the battery while the engine is running.

Fitment: Match the number on your old unit. It's listed for the Case 460 Trencher and 1825B, Grasshopper 928D, Gravely PM460, and Kubota R310, D1005, G2160, G2460G, TG1860 and TG1860G. Cross-references: Case 125564A1; Kubota 16231-64010, -64011, -64012, 66436-64011, -64012; Nippondenso 100211-4520, -4740; Lucas LRA01560; Remy RA00136.

Specs: 12V, 40A, internal regulator (9:00) and fan, negative polarity, M6-1.0 stud, about 6.9 lb.

Installation: Disconnect the negative cable, photograph and label the wires, and remove the old unit. Compare mounts and pulley, fit the new one, set belt tension and reconnect. Then start the engine, check the belt, listen for noise, measure voltage and test accessories.

Maintenance: Check the belt, keep the unit clean (no pressure washing), tighten connections, test the battery, check voltage each season and watch for noise or dim lights. Disconnect the negative cable before any work.

FAQs: Yes, Kubota tractors have alternators. Common symptoms are a warning light, dim lights and repeated dead batteries. They use 12V batteries, but the size varies by model, so check your manual.

Before ordering, confirm the part number, engine and specs, then test your charging system afterward. View the Denparts alternator.