BUSHING CLUTCH SHAFT
Sintered flywheel bushing
Clutch Pilot Bushing
For flywheel/crankshaft
Bronze bushing pressed into the centre of the flywheel that centres and supports the gearbox input shaft. Essential component for correct clutch operation and reduction of transmission component wear.
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Material Bronze |
Part no. 639578 |
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Application L-head and F-head 4-cylinder engines |
Dimensions Ø 1-1/16" outside, Ø 5/8" inside, 7/16" length |
Features
- Replaces original part 639578
- Pressed bronze construction
- Centres the transmission input shaft
- Reduces vibration and wear
- Always replace when replacing clutch
★ High-quality bronze bushing manufactured exactly to original specifications. A must for any clutch overhaul.
Application
Fits all vehicles listed in the categories: Willys MB, Ford GPW, Hotchkiss M201, CJ-2A, CJ-3A, CJ-3B and M38 with 4-134 L-head or F-head engines. Suitable for both early and late versions.
Installation notes
Bushing is pressed into the centre of the flywheel (or crankshaft end). Install with suitable drift or deep socket to prevent damage. Note: after installation, line boring may be necessary for correct fit on the input shaft. Always check the inside diameter after assembly. Removal can be done with hydraulic method (grease + drift rod) or with special puller.
Compatibility
Universal for 4-134 L-head (Go Devil) and 4-134 F-head engines. Inside diameter must be 0.002" to 0.005" larger than outside diameter of the transmission input shaft for correct operation. Does NOT fit later 6-cylinder engines (which use a different size).
Historical context
Bushing 639578 was produced for all Willys 4-cylinder engines from 1941 and remained in use until the early 1970s. Original bushings were of pressed, oil-impregnated bronze — the same specification that remains the standard today.
This description was generated automatically. Unsure about fitment? Contact us at info@willys.be.
⚠ Spotted an error in this description? Report it to info@willys.be
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.
ALL_CATEGORIES : CRANKSHAFT - MB/M201/GPW, LOWER ENGINE CJ2A, CRANKSHAFT CJ3A, GROUP 02 - CLUTCH CJ3A, LOWER ENGINE M38, CRANKSHAFT - M38, GROUP 02 - CLUTCH - M38, GROUP 02 - CLUTCH - M38A1, GROUP 02 - Clutch CJ3B, CRANKSHAFT CJ3B
This part fits:
| Model | Years |
|---|---|
| Military jeeps | |
| Willys MB (early) | 1941, 1942 |
| Willys MB | 1942, 1943, 1944, 1945 |
| Ford GPW (early) | 1942 |
| Ford GPW | 1942, 1943, 1944, 1945 |
| Hotchkiss M201 | 1956, 1957, 1958, 1959, 1960, 1961, 1962, 1963, 1964, 1965, 1966 |
| Willys M38 | 1950, 1951, 1952 |
| Willys M38A1 | 1952, 1953, 1954, 1955, 1956, 1957, 1958, 1959, 1960, 1961, 1962, 1963, 1964, 1965, 1966, 1967, 1968, 1969, 1970, 1971 |
| CJ series | |
| Jeep CJ-2A | 1945, 1946, 1947, 1948, 1949 |
| Jeep CJ-3A | 1949, 1950, 1951, 1952, 1953 |
| Jeep CJ-3B | 1953, 1954, 1955, 1956, 1957, 1958, 1959, 1960, 1961, 1962, 1963, 1964, 1965, 1966, 1967, 1968 |
| Jeep CJ-5 | 1955, 1956, 1957, 1958, 1959, 1960, 1961, 1962, 1963, 1964, 1965, 1966, 1967, 1968, 1969, 1970, 1971, 1972, 1973, 1974, 1975, 1976, 1977, 1978, 1979, 1980, 1981, 1982, 1983 |
📐 Diagrams & technical drawings
From the original Technical Manual CJ2A_PL_1949 — Parts List — only for Willys CJ-2A / CJ-3A (1949)
From the original Technical Manual TM 10-1513 — Maintenance Manual — only for Willys MB / Ford GPW (1942)
