Valve Spring: Application and ID

23 Valve guide
62 Valve spring retainer
63 Capnut
63a Counternut
64 Valve spring
66 Valve stem seal
69 Rotocap
70 Valve


NOTE: Each valve has one valve spring (64) and one rotocap (69).

On engines with long service life, it is recommended to renew rotocaps at the same time.

Valve springs with higher spring tension are installed on engine 617.950 since January 1979 and on engines 617.951/952 since start of series.

On engine 617.951/952, do not install valve spring, part No. 180 053 06 20.

On the other hand, on engine 617.950 (USA) up to model year 1980 with increased output, valve spring part No. 615 053 01 20 may also be installed.

Production breakpoint

Engine Starting vehicle ident end No.
617.950 006303
617.951/952 Start of series

Identification:
Valve spring, part No. 180 053 06 20, two green or purple-green color dots.

Valve spring, part No. 615 053 01 20, two yellow or purple-yellow color dots.

Renew damaged cap nuts (63). Cap nuts are available in three versions:






1st version: Cap nut with small supporting surface (A).

2nd version: Cap nut reinforced in upper range, with larger supporting surface (B).

3rd version: Cap nut reinforced in upper range and hard-chromed.

Identification: silver colored.

On engines with chilled cast iron camshaft and rocker arms with carbide facing, only the hard-chromed cap nut may be installed.

The hard-chromed cap nut can also be installed on engines with chilled cast iron camshafts and rocker arms with inductance-hardened and hard-chromed running surface.

Spare parts (ET) Sindelfingen will keep only hard-chromed cap nuts in stock.






Punched valve spring retainers (B) are installed instead of cold flow molding valve spring retainers (A). The punched valve spring retainer is recognized by the narrow guide ring for valve spring (B, dotted surface).

In the event of repairs, these valve spring retainers (B) can be installed on engines installed up to now.

Production breakpoint: February 1981

Salt bath-nitrited counternuts (formerly phosphatized) are installed to improve operational reliability.

When stocks are exhausted, only the modified counternuts will be available.

The part number has not been changed.






Production breakpoint: October 1983