Detailed technical specifications (BMW 3 Series E21)

Rear suspension

The rear suspension is independent, with telescopic heavy struts. It includes longitudinal inclined levers, which are pivotally attached to the rear suspension crossmember, which also serves as a support for the rear axle, hydraulic shock absorbers, coil springs, compression buffers and an anti-roll bar (except for "315" and "316").

Wheel travel up, mm: 110.

Wheel travel down, mm:

• 4-cylinder cars: 120;
• cars with 6-cylinder engines: 130.

Thickness of rubber bushing (catalog no.: all models except "323i": 1 114 966; "323i": 1 118 320) upper support cup of suspension spring, mm:

• all models except "323i": 20;
• "323i": 26.

Thickness of the rubber bushing (catalog No.1 114 966) of the lower support cup of the suspension spring, mm: 20.

Shock absorbers

Double-acting hydraulic telescopic shock absorbers.

Stroke length, mm: 190.

Anti-roll bar

All models except the 315 and 316 have a stabilizer bar in the rear suspension.

Stabilizer bar diameter, mm:

• all models except "323i": 16;
• "323i": 17.

Shock absorbers used in cars

* Installed on vehicles with reinforced front suspension.
** Installed on vehicles with conventional front suspension.

Data for checking shock absorbers

Rear suspension spring characteristics

Rear axle

Rear wheel alignment angles

For a vehicle with a full fuel tank and a load distributed as 68 kgf on the front seats plus 68 kgf on the rear seat plus 21 kgf of cargo in the luggage compartment, the wheel alignment angles should be as follows:

• toe-in — 1±1 mm
• negative camber - 2±30'

Distance between the lower edge of the wheel cover and the edge of the wheel rim, mm:

• under load (see above): 492±8;
• without load: 530±10.

Rear wheel hubs

The wheel hub rotates in two ball bearings. Hub bearing type on cars with 4-cylinder engines: early model years 63/30 C3; in the following: 62/63 C3. Hub bearing type on vehicles with 6-cylinder engines: inner bearing: 62/30 C3; outer bearing 62/06 C3.



Axial clearance in hub bearings, mm: 0.05–0.1.

Amount of grease (type Shell Retinax AM), embedded in bearings, g:

• cars with 4-cylinder engines: about 40;
• cars with 6-cylinder engines: 35.

Tightening torques of main threaded connections, kgf·m

• Fastening nut (M8) of the mounting cup of the telescopic strut to the body: 2.5-2.9.
• Fastening nut (M10) of the telescopic jalopy rod to the mounting cup: 2.0-2.5.
• Nut of the bolt securing the telescopic strut to the suspension arm: 4.9-5.4.
• Nut of the bolt securing the suspension arm to the rear suspension crossmember: 8.1-9.0.
• Brake shield to suspension arm mounting bolt: 6.0-6.7 (apply a thread sealant such as Loctite 270 to the threads first).
• Anti-roll bar bracket mounting nut: 2.2—2.4.
• Bolt for fastening the flange of the wheel drive shaft to the flange of the differential output shaft: 3.3-3.7.
• Wheel mounting bolt: 8.1-9.0.