Drawing of the DS 314-35 clutch control piston stop nut
Dimensioned drawing of the DS 314-35 clutch control piston stop nut, signed by Guyétant, Belloncle and Bourget, validated by the Labo MT BEA in January 1957.
Understanding this document
In this document
This technical drawing from the Société Anonyme André Citroën designates the clutch control piston stop nut referenced DS 314-35 p. 16.
Main dimensions
The part is dimensioned in section with several diameters and lengths:
| Dimension | Value | Page |
|---|---|---|
| Diameter | Ø 21 pitch 1.5, threaded type plated on F | p. 16 |
| Diameter | Ø 19.5 / 19 | p. 16 |
| Diameter | Ø 16 | p. 16 |
| Diameter | Ø 13.5 | p. 16 |
| Length | 7 +0.5/0 | p. 16 |
| Length | 13.5 ±0.15 | p. 16 |
| Length | 6 ±0.5 | p. 16 |
| Angle | 10° ±1° | p. 16 |
| Width (front view) | 5 | p. 16 |
A note specifies that "thread marks [are] accepted" p. 16, and a handwritten correction "m1" modifies a dimension of 7 p. 16.
Material and weight
The specifications table indicates a C 3 steel, without any particular treatment or coating. The initial manufacturing weight (12) was crossed out and corrected by hand to 14, and the limit weight (13) corrected to 14.7 p. 16.
Title block and signatures
The drawing was "released by note no. 28311" and replaces a drawing for the DS 314-02 assembly p. 16. It bears the visas of Guyétant, Belloncle, Bourget (industrialisation, verification, drawing), dated 4.1.57 / 2.1.57, as well as those of the Labo MT BEA: Pompon, Caneau, Cadiou p. 16.
Context
The acronym BEA refers to the Bureau d'Études Automobiles (Automotive Design Office) of Citroën, where Paul Magès developed the hydropneumatic suspension equipping the future DS, presented in 1955. The DS hydraulic clutch control system is part of this same technical culture of high-precision parts, combining hydraulics and fine mechanics — a know-how characteristic of the BEA of this period.
Archivist's perspective
This dimensioned drawing illustrates the meticulous standardisation work of spare parts carried out by the BEA teams around 1957, probably in direct connection with the development of the DS 314-02 clutch control assembly, which this drawing explicitly indicates replaces an earlier version p. 16.
The handwritten corrections on the limit weights suggest adjustments made after an initial manufacturing inspection, a common practice in the development files of that time.
This document finds a direct echo in two other parts of the same date, concerning the same sub-assembly: the Drawing of the DS 314-02 clutch cylinder and leak meter test and the Drawing of the DS 314-12 clutch control piston, both dated 4 January 1957, which indicates a coordinated revision of the entire clutch system at that time.
Dating
4 January 1957
Document
1 page
Source: « Scanner 6 août 2025 à 14.10.pdf », p. 16
Category
Archival note
Page 16: reference DS 314-35 and dates 2.1.57 / 4.1.57 in the title block.