PUMP OIL CHAIN TYPE
For engines with chain
Oil pump chain-drive L-134
For early Willys MB, Ford GPW and early CJ-2A
Replacement oil pump suitable for the early L-134 'Go Devil' engine with chain-driven camshaft. This version was used in all WWII Willys MB and Ford GPW jeeps (1941-1945), as well as early CJ-2A models until mid-1946.
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Engine type L-134 with chain-drive |
Drive Right-hand helical gear |
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Applications Willys MB, Ford GPW, Hotchkiss M201, early CJ-2A |
Part number WO-637636 / 804769 |
Features
- Suitable for chain-drive camshaft system (1941-1945)
- Right-hand helical drive gear for correct rotation direction
- Replaceable by later 804769 version
- Original Willys-Overland specification
- NOT compatible with gear-drive engines without modification
★ This oil pump is specific to the early L-134 engine with timing chain. Note: from mid-1946 (CJ-2A engine #44418) the change was made to gear-drive, which requires a different pump with left-hand helical gear.
Application
Willys MB (1941-1945), Ford GPW (1941-1945), Hotchkiss M201 (early 6V versions with chain-drive), and CJ-2A built before July 1946 (engine number lower than 44418). Note: Willys temporarily used chain-drive engines again during certain production periods (including engine #47201-48537 and #212689-227427).
Installation notes
Check before fitting that your engine actually has a timing chain (no gears on camshaft). The drive gear has right-hand helical teeth — this ensures counterclockwise rotation of pump and distributor. The slot on the pump shaft must engage with the tooth on the distributor drive. Always prime the pump before starting the engine.
Compatibility
This pump fits ONLY chain-drive L-134 engines. Gear-drive engines (late CJ-2A from mid-1946, CJ-3A, CJ-3B, M38, M38A1) require a different pump with left-hand helical gear (WO-804484). The pumps are technically interchangeable if you also swap the drive gear, but this is not recommended for a correct restoration.
Historical context
The L-134 'Go Devil' engine with chain-drive was used in all WWII production jeeps. From July 1946, Willys changed to the more reliable gear-drive, although chain-drive engines were occasionally used when surplus WWII parts were being used up.
This description was generated automatically. Unsure about fitment? Contact us at info@willys.be.
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This part is intended for the restoration of historic military vehicles. Fitting, aligning, deburring or reworking is part of that work and is inherent to the nature of these goods. Dimensional variation also exists between original vehicles.
Installation requires technical knowledge of the vehicle. Unsure whether this part suits your version? Ask us before purchase at info@willys.be.
This part fits:
| Model | Years |
|---|---|
| Military jeeps | |
| Willys MB (early) | 1941, 1942 |
| Willys MB | 1942, 1943, 1944, 1945 |
| Ford GPW | 1942, 1943, 1944, 1945 |
| Hotchkiss M201 | 1956, 1957, 1958, 1959, 1960, 1961, 1962, 1963, 1964, 1965, 1966 |
📐 Diagrams & technical drawings
From the original Technical Manual TM 10-1513 — Maintenance Manual — only for Willys MB / Ford GPW (1942)
