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Connecting Rod Cap - New Screws

Section
2

Group
21

No.
0005

Year
98

Month
03

Reference:
TP 2103201, Section 2(21) Engines B6244, B6254, B6304; 960 1991-

New screws for connecting rod cap

Background:
A new screw for the engine connecting rod cap has been introduced from and including model year 1998 for all S90/V90 gasoline engines.

The new screw has a closer pitch of thread.
At the end of model year 1997 production approximately 800 engines were manufactured with this new type of screw. It is therefore important to check which type of screw the engine is equipped with if an engine from a model year 1997 car is being renovated, and whether the screw needs to be replaced. When replacing screw, it must be replaced with same type of screw, in other words with the same pitch of thread.

This Service Bulletin describes how to spot the difference between the old and the new type of screw, and within which engine serial numbers mixed screw types are to be found.

Screw type Engine serial number Notes

Only older screws -1051765

Mixed old and new screws 1051766 - 1052536 A) see below

Only older screws 1052537 - 1059933

Mixed old and new screws 1059934 - 1059984 B) see below

Only new screws 1059985-

A) The following engines have NEW screw:

1051766-1051771, 1051778-1051783, 1051796-1051801, 1051814-1051819, 1051844-1052225, 1052240-1052245, 1052252-1052257, 1052264-1052269, 1052276-1052281, 1052288-1052293, 1052300-1052305, 1052312-1052317, 1052324-1052329, 1052336-1052341, 1052348-1052365, 1052384-1052389, 1052396-1052401, 1052420-1052425, 1052438-1052443, 1052462-1052467, 1052480-1052497, 1052504-1052536

B) The following engines have NEW screw:

1059934-1059935, 1059942-1059947, 1059954-1059959, 1059966-1059977

Tools
Thread gauge M9 x 1.0 1158902-5 (or equivalent)
Thread gauge M9 x 1.25 1158901-7 (or equivalent)

New screws for connecting rod cap





Identifying screw types

Older screw to left of illustration
Older screws from factory have M9 x 1.25 angle of thread and have no markings on the screw head.

Old screws as replacement part (P/N 1271900-1) have a circular stamp in the screw head.

New screw to right of illustration
New screws from factory have closer M9 x 1.0 angle of thread and have no markings on the screw head.

New screws as replacement part (P/N 9125471-4) have a triangular stamp in the screw head.

Thread gauge
Thread gauges can also be used to check which type of screw is used. This may be required if there is no marking on the screw head.