Notes regarding crankcase - RA01001041000X(01-1000)

Operation no. of operation texts and work units or standard texts and flat rates

Model designation identification 

Replacement crankcases and short blocks do not have a stamped engine model designation and engine number.

The workshop performing repairs must stamp the engine model designation in the crankcase in the space provided for the engine number (arrow) on the right in front of the engine support to enable the engine of the vehicle to be properly identified (e.g. by vehicle inspection authority after vehicle has been laid up or by Customs if vehicle is exported etc.).

Example:

104.941 (engine model designation in model 202.028), see also (01-0010) .

The engine compression ratio ( ) is stamped after the engine number.

Fig 1: Locating Engine Number

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

Since January 1991 crankcases with additional bearing seat openings on the side (1) have been used as standard.

This improves the pressure distribution in the crank chamber.

Threaded holes in crankcase, see (01-1220) .

Fig 2: Identifying Additional Bearing Seat Openings On Side

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

The crankcase of engine 104.990 has been strengthened with additional cast ribs (1) at the outer contours. This results in a change in the knock sensor signals (KSS) which necessitates a modified ignition control module (DI).

Production breakpoint April 1991 (2nd version)

as of engine as of vehicle ident no.

104.990-10-000 081 140.032/033-1A-002520

104.990-12-001 169

As of April 1991 2nd version

Fig 3: Identifying Additional Cast Ribs - As Of April 1991 2nd Version

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

When replacing the crankcase or installing a reconditioned engine, the matched ignition control module (DI) should be used (see table). Except for USA models.

Up to April 1991 1st version

Fig 4: Identifying Additional Cast Ribs - Up To April 1991 1st Version

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.