Main Bearings - Cross Reference

91mercedes01

REF. NO. MBNA 03/4


TO: OUR MERCEDES-BENZ PASSENGER CAR DEALERS

DATE: January 1991


SUBJECT: CROSS REFERENCE, MAIN BEARINGS RELATIVE TO CRANKCASE

Figure 1:

With the introduction of engine 102 for Model Year 1984, this and all other engine designs (diesel and gasoline) thereafter have main bearings and matching crankcases identified by code numbers.

In case of major engine repairs, the following precautions must be followed:


Cross Reference

Main Bearing Journals (1) Basic Bore Diameter In Crankcase

Center punch marks (2)
1 2 3

Bearing Shell to be Installed Color Codes

Blue Blue Yellow Yellow

Yellow Blue Yellow Red

Red Yellow Yellow Red

(1) Color code on counterweights next to journal bearing (2) Center punch marks on crankcase contact surface facing oil pan (Figure 1)


Standard size main bearings are available as spare parts with color codes in red, yellow or blue. When used according to the table above, measuring the bearings is no longer required.

When ordering standard size main bearings, use the correct code in addition to the part number:

Code 52 = Color blue Code 54 = Color yellow Code 56 = Color red

Oversize bearings have to be measured according to the respective repair instruction on microfiche.

Connecting rod bearings are available as spare parts only with color code yellow. It is not necessary to add code 54 to the part number.