Engine - Production Changes

84mercedes01

TO: OUR MERCEDES-BENZ PASSENGER CAR DEALERS

DATE: December, 1984 REF.NO.. 03/39
SUBJECT: PISTON-GUIDED CONNECTING RODS
ENGINE 102

FIGURE 1:

To limit axial play, the pistons of engine 102.961 now have two thrust bearing surfaces (arrows) at the inner faces of the wrist pin bore (piston-guided connecting rods). Previously, the axial play was limited at the crankshaft. The connecting rod bearing caps are secured with two screws (1) (previously with bolts and nuts). The connecting rods are 22 mm wide (dimension "A"). Refer to Figure 1.
Production Phase-In


Model As of chassis end no.


201.024 A 050914
F 003323

To accomodate the new connecting rods, the oil channelling fins on the oil pan have a curved cut-out to eliminate interference with connecting rods 3 and 4.

FIGURE 2:

Repair note

The piston-guided connecting rods together with the modified pistons and oil pan can be installed in vehicles with lower chassis end numbers.

IMPORTANT: If the previous-type oil pan is used the curved cut-out (dotted lines) must be machined according to Figure 2.

FIGURE 3:

The connecting rod screws must have a diameter of at least 7.1 mm (c, Figure 3). Replace stretch screws with a smaller diameter.
Torquing specifications

Initial torque 30-35 N-m
Final torquing angle 90-100~
Parts Information


Part Name Part Number Engine

Connecting rod (520g) 102 030 05 20 102
Connecting rod bearings (4 pairs) 102 030 06 60 102
Connecting rod screw 102 038 00 71 102
Piston 102 030 17 19 102.961
Oil pan 102 010 34 13 102


IMPORTANT: Engine 102.985 installed in model 201.024 for model year 1985 also has piston-guided connecting rods. Refer to the latest parts microfiche for current part numbers.