S 500 Coupe (140.070) V8-5.0L (119.980) (1997)
/v8-5.0l_(119.980)/Page-690008.png)
-
Crankshaft Bearing Stud Bolt
M 10 x 1 Nut: 50 Nm
M 10 x 40 Side Bolt (10.9): 50 Nm
NOTE: The stud bolts loose their locking effect after being unscrewed and therefore should be replaced.
Procedures
CAUTION: When performing repairs, no HELI-COIL inserts may be used for the self-locking stud bolts of the crankshaft bearing caps.
NOTE:
-
Self-locking stud bolts are inserted into the crankcase for attaching the crankshaft bearing caps.
-
The stud bolts should only be used once as the locking fluid applied over a length of about 8 mm of the thread is rendered ineffective when the
bolts are unscrewed.
-
Pay attention to different insertion depth and collar diameter when replacing the stud bolts.
-
The 5 crankshaft bowing cap are manufactured from malleable cast iron and are interference fitted in the side of the crankcase (arrows).
-
The fit (arrows) is off-centered with the result that the bearing caps can only be installed in one position.
-
The three center bearing caps are additionally bolted to the side walls of the housing.
-
The crankshaft bearing caps are machined together with the crankcase and are not available as a replacement part.
-
Standard bearing shells and thrust washers are installed at the 3rd crankshaft bearing (fit bearing).
-
The thrust washers absorb the axial forces of the crankshaft.
-
The thrust washers (13 and 14) inserted on both sides of the crankcase and the bearing cap, are identical.
-
The thrust washers in the bearing cap each have two retaining lugs, the bottom lugs being positioned off-center, as an anti-twist lock and to avoid
incorrect installation.
-
In addition, all the thrust washers are chamfered at one end.
-
The two oil grooves in the thrust washers must face towards the crank webs.
-
When repairing crankshafts, the fit bearing journals should be re-ground in width to one of the dimensions stated in the table above.
-
After bearing damage has occurred, the conrod should be taken out and any metal particles present in the conrod bores and in the crankshaft oil
galleries, removed.
-
Carefully clean oil galleries in crankcase, crankshaft, timing case cover, oil fitter housing, end cover, oil pump etc.
-
Inspect crankshafts for cracks, dimensional tolerance and hardness.
Matching Crankshaft Bearings, Installing Crankshaft
1. Install crankshaft bearing caps.
-
Pay attention to marking.
-
1 is at the front.
