Detailed technical specifications (BMW 3 Series E21)

The front suspension is independent, of the "swinging candle" type, with hydraulic shock absorber struts installed at an angle to the rear of the car, with helical, eccentric cylindrical springs, lower transverse arms that form a single unit with the reaction rods, and an anti-roll bar.

The telescopic strut is equipped with a coil spring, a rubber compression buffer and an upper support of the strut. The upper support is attached to the mudguard strut of the body. The strut rests on the ball joint of the suspension arm.

The anti-roll bar is a rod whose knees are connected to the suspension arms via rubber-metal hinges. The middle part of the rod is attached to the body with brackets with rubber pads.

Wheel travel up, mm:

• 4-cylinder engine cars: 83;
• cars with 6-cylinder engines: 100.

Wheel travel down, mm:

• 4-cylinder cars: 109;
• cars with 6-cylinder engines: 110.

Compression Stroke Buffer

Length, mm:

• all models except "323i" 95±1.
• "323i": 85±1.

Outer diameter, mm 60±1.

Shock absorbers

Hydraulic telescopic shock absorbers of double-sided type with replaceable cylinder.

Shock absorber brand:

• cars with 4-cylinder engines: Fichtel, Sachs or Boge;
• cars with 6-cylinder engines: Boge.

Letter index on the shock absorber hexagon:

• cars with 4-cylinder engines: "a" or "c" (Fichtel and Sachs) or "d" (Boge);
• cars with 6-cylinder engines:
• "320": "f";
• "323i": "e".

Length of shock absorber with extended piston rod, mm, no more than: 660±3.

The length of the shock absorber with the piston rod retracted and the piston rod travel reserve of 5 mm, not less than: 480.0–472.5.



Volume of engine oil contained between the strut housing and the shock absorber cylinder, cm³: 3.

Front suspension spring characteristics

Data for checking shock absorbers

Anti-roll bar

Stabilizer bar diameter, mm:

• cars with 4-cylinder engines, except "320i" and "318i": 22;
• cars with 6-cylinder engines and "320i" and "318i": 23;
• cars with reinforced suspension: 23.

Front axle

Front 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:

• camber — 0°±30' (for reference)
• toe-in — 1.5±0.5mm

Pivot axis tilt angle:

• longitudinal — 8°20'±30' (for reference)
• transverse — 10°54'±30'

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

• under load (see above): 542±8,
• without load: 580±10.

Front wheel hubs

The wheel hub rotates in two tapered roller bearings.

Axial clearance in hub bearings, mm: >0—0,05.

Permissible end runout of the hub on the brake disc installation side (non-flatness in the bearing seat area), mm, no more than: 0.05.

Amount of grease (type Shell Retinax A), pledged:

• in bearings: 50;
• in the hub cap: 20.

Rolling bearings

Tightening torques of main threaded connections, kgf·m

• Nut for fastening the telescopic strut rod to the upper support: 7.8-8.6.
• Upper support fastening nut to the body: 2.2-2.4.
• Strut housing nut: 12.0-14.0.
• Nut for fastening ball joints to front suspension crossmember: 6.0-7.0.
• Bolt and nut for fastening the suspension arm to the front suspension crossmember: 8.1–9.0.
• Nut securing the front suspension crossmember to the engine mount bracket: 4.3-4.8.
• Brake disc mounting bolt to wheel hub: 1st version: 6.0-6.7; 2nd version of execution (110 cylindrical head bolts): 0,4 —0,5.
• Steering rod to steering knuckle mounting nut: 3.5-4.0.
• Wheel mounting bolt: 8.1±9.0.