Tightening torques for main threaded connections (BMW 5 Series E12)

Tightening torques of main threaded connections, kgf·m

• Cylinder head mounting bolts (on a cold engine): 1st dose: 3.5-4.5; 2nd dose: 6.0-6.5; 3rd dose: 7.5±0.2.
• Main bearing cap mounting bolt: 5.8-6.3.
• Connecting rod cap bolt nut: 5.2-5.7.
• Flywheel mounting bolt: 10.0-11.5 (pre-lubricate the threads with a special glue such as "Loctite").
• Lock nut of the valve drive thermal clearance adjustment screw 0.9-1.1.
• Bolts for fastening the oil pan and timing gear drive covers: 0.9-1.1.
• Spark plugs: 2.5-3.0.
• Fuel pump mounting bolt: 1.0-1.4.

Since the 1978 model year, some tightening torques for threaded connections on BMW models have been changed "525", "528" and "528i".

Tightening torque of cylinder head mounting bolts on a cold engine in three steps with repetition of the 3rd step, kgf·m: 3.5-4.5; 6,8-7.2; 7.8-8.2 (2 times).

Since the 1980 model year, the following new tightening torques for threaded connections have been introduced, kgf·m.

Cylinder head bolts on all models: 1st step: 3.4-4.4; 2nd reception: 6.7-7.1; wait 15 minutes; 3rd reception: 7.8-8.2; Step 4: turn further by 25°±5°.

Crankshaft main bearing cap bolts on all models: 5.8-6.5.

Flywheel mounting bolt on all models: 9.8-11.3 (the bolt should be installed using glue such as Loctite Frenbloc).

Connecting rod cap bolt nut on all models: 5.1-5.6.

"520", "520i" with 6-cylinder engines

Main bearing cap mounting bolt: 5.8-6.5.

Cylinder head mounting bolts: 1st step: 3.0-3.5; 2nd reception: 6.0-6.5; Step 3: turn further by 25°±5°.

Oil pan and timing cover mounting bolts: 0.9-1.1.



Flywheel mounting bolt (with the application of a special adhesive such as Loctite to the threads): 9,8-11,3.

Rocker arm adjusting eccentric nut: 0.9-1.1.

Connecting rod cap bolt nut: 1st pass: 2.0; 2nd step: turn further by 70°.