NUT PITMAN 5/8-18
Pitman Arm Nut 5/8-18
For securing pitman arm to sector shaft
Lock nut for securing the pitman arm to the threaded sector shaft of the steering box. This nut with 5/8-18 thread is suitable for early Willys and Jeep models fitted with the original Ross steering box at the rear of the engine compartment.
|
Thread 5/8-18 UNF |
Material Steel |
|
Application Ross steering box |
Part number 639115 |
Features
- 5/8-18 thread for sector shaft
- Secures pitman arm to steering box
- Essential component of the steering system
- Original specification
- Replacement part to factory standards
★ This nut is identical to the original part and ensures correct fitment of the pitman arm. The steering system is as critical as the drivetrain — quality parts are essential for safe restoration.
Installation notes
Ensure the pitman arm is fully engaged on the splines of the sector shaft before tightening the nut. The nut must be firmly tightened to prevent play in the steering mechanism. Check after fitting that the drag link is correctly connected.
Compatibility
Note: This nut with 5/8-18 thread is ONLY suitable for the early Ross steering box as fitted to the models listed in the categories. Later models use a larger sector shaft (15/16" or 1") with a different nut. Not suitable for Saginaw steering boxes (late CJ models from 1972 onwards) which use a 7/8-14 nut.
Historical context
The Ross steering system was fitted to the earliest Willys jeeps and remained in production until the early 1970s. The 7/8" diameter sector shaft and its corresponding 5/8-18 nut formed a robust steering system for both military and civilian jeeps.
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 : BOLTS 14 STEERING, DIRECTION HOUSING CJ2A, DIRECTION HOUSING CJ3A, DIRECTION HOUSING CJ3B
This part fits:
| Model | Years |
|---|---|
| Military jeeps | |
| Willys MB (early) | 1941, 1942 |
| Willys MB | 1942, 1943, 1944, 1945 |
| Hotchkiss M201 | 1956, 1957, 1958, 1959, 1960, 1961, 1962, 1963, 1964, 1965, 1966 |
| Willys M38 | 1950, 1951, 1952 |
| CJ series | |
| Jeep CJ-2A | 1945, 1946, 1947, 1948, 1949 |
| Jeep CJ-3A | 1949, 1950, 1951, 1952, 1953 |
📐 Diagrams & technical drawings
From the original Technical Manual CJ2A_PL_1949 — Parts List — only for Willys CJ-2A / CJ-3A (1949)








