560SL (107.048) V8-5.6L (117.967) (1989)
Timing Chain Tensioner: All Technical Service Bulletins
Engine - Updated Timing Chain Tensioner
REF. NO.: 05/87
TO:
OUR MERCEDES-BENZ PASSENGER CAR DEALERS
DATE:
October 1991
SUBJECT:
ALL MODELS WITH ENGINE 116.96 AND 117.96
TIMING CHAIN NOISE WHEN STARTING ENGINE
MODIFIED CHAIN TENSIONER
As of February 1989, a modified chain tensioner is installed in the above-listed engines. A number of modified chain tensioners were also installed in
production during the period October to December 1987 as per the Effective Serial Number Range.
Figure 1
Complaints of timing chain noise when starting the engine can be traced to the previous version timing chain tensioner. When shutting off the engine,
oscillation from the crank assembly, in some cases, causes the thrust pin (12, Figure 1) to compress excessively.
An additional filler piece (7) in the compression spring limits the rearward travel of the thrust pin and reduces the compression area so that the chain
tensioner reacts faster. Furthermore, an additional compression spring (5) in the supply valve allows a quicker pressure build-up (Figure 1).
In case of complaints about timing chain noise or when performing repairs to the chain drive, use only the modified chain tensioner. The modified chain
tensioner must also be used in earlier production engines.
Effective Serial Number
Model
Engine
Engine End Number
Chassis End Number
107.048
117.967
045973
A 099193
126.035
116.965
069128
A 467531
126.039/045
117.968
065319
A 467294
Effective Serial Number Range (October - December 1987)