Rear Axle Specifications (BMW 5 Series E12)

The rear axle is sprung, with a hypoid final drive. The main drive pinion rotates in tapered roller bearings.

Main gear characteristics

Lateral clearance between the teeth of the driving and driven gears, mm: 0.06-0.11.

Clearance between the support and adjusting washers of the axle gear, mm: 0.05-0.06.

Moment of resistance to rotation of semi-axial gears, no more than, kgf·m: 1 (at tightening points for new satellites, no more than, kgf·m: 2).

Moment of resistance to rotation of the bearings of the drive gear, kgf·cm:

• without seal: 30;
• with seal: 32.

Preload of differential box bearings (for new bearings), kgf·cm: 14-16.

Heating temperature of the driven gear during installation, °C: 80-100. Permissible runout of the drive gear flange, no more than, mm: 0.03.

BMW Rear Axle Performance Features "525", "528" and "528i" from the 1978 model year

Rear Axle Performance Features Since 1980 Model Year

Rear Axle Performance Features Since 1982 Model Year

Rear axle oil

Oil used: SAE 90 hypoid oil.

Oil change is not provided. Oil should reach the level of the lower edge of the filler hole.

Rear axle housing filling capacity, l:

• before 1982 model year: 1.6;
• since 1982 model year: 1.8;
• BMW "535": 1,9.

Rear wheel drive

The drive of each wheel consists of two constant velocity ball joints and a shaft.

Maximum angle of inclination of the wheel drive shaft, degrees: 18.

The gap between the side surface of the hinge and the flange when measured at a radius of 25 mm, mm: 0.08.

Maximum permissible displacement, mm:

• hinge:±6;
• axle shafts: 12.

The amount of grease added to the hinge housing during assembly, g: 80 (for example. Shell Retinax AM).



Recommended brand of sealant to use when installing the hinge cover: Curil K.

Tightening torques of main threaded connections, kgf·m

• Nuts for bolts securing the cover to the rear axle housing: 2.0-2.5.
• Bolts securing the driven gear to the differential box:
• "518", "520", "520i": 8,5-9,5 (the bolts are installed using a special adhesive such as Loctite 270);
• "525". "528": 13,0-15,0 (the bolts are installed using a special adhesive such as Loctite AVV).
• Nuts for bolts fastening the cardan shaft flange to the drive gear flange: 15.0.
• Bolts for fastening the axle shaft to the differential output shaft flange: 3.0-3.3.
• Nuts for bolts securing the rear axle housing to the body bracket: 14.0-15.5.

Since 1978 model year

• Bolts for fastening the driven gear to the differential box: 16.5-19.5.
• Bolts for fastening the axle shaft to the differential output shaft flange: 4.0-4.5.

[The website served as the basis for the text: «BMWMAN»]