Detailed technical specifications (BMW 3 Series E21)

The four-speed gearbox is manufactured by Getrag with Borg-Warner synchronizers on all forward gears. Gear shifting is performed by a lever on the body floor tunnel.

Types of gearboxes used in cars

Gear ratios

Rolling bearings used in gearboxes

Gearbox housing heating temperature when pressing in bearings,°C: 80.

Rolling bearings of the secondary shaft of the gearbox

* Before model year 1977.
** Since 1978 model year.

Adjusting rings for gearbox shaft bearings

Data for adjustment

Axial clearance between the end face of the new locking ring and the end face of the synchronizer ring gear, mm: 1.0.

Minimum axial clearance between the end face of the locking ring and the end face of the synchronizer ring gear, mm: 0.8.

Width of guide rib, mm (up to model year 1977):

• shift forks I and II, III and IV gears: 5^-0,030_+0,078.
• reverse gear shift forks for 4-cylinder engine vehicles: 6^-0,07_-0.145.

Width of the guide rib of the gear shift forks, mm (since 1978 model year): 13,95^-0,1.

The intermediate shaft can be partially disassembled. Only the gear rims of the first and second gears are made on it. The pressing and pressing of the third and fourth gears must be done on a press.



Pressing force of gears of III and IV gears of intermediate shaft, tf: 10.

The pressing force of the gears of the III and IV gears of the intermediate shaft (they must first be heated to a temperature of 120-150°C), tf: 4-6.

Runout of the secondary shaft when measured by the journal, mm, no more than: 0.07.

Axial clearance, mm:

• primary shaft: 0.12-0.18;
• secondary shaft: 0.14-0.20.

Speedometer drive ratio: 10/4.

Gearbox oil

Gearbox housing filling capacity, l: 1.0.

The oil used is gearbox oil SAE 80; MIL L-2105; API GL-4.

Frequency of checking the oil level: every 15,000 km (the oil should be at the level of the lower edge of the filler hole).

Oil change interval: every 30,000 km (immediately after the trip).

Tightening torques of main threaded connections, kgf·m

• Gearbox housing to engine block mounting bolt: M8: 2.2-2.4; M10: 4.7-5.1; M12: 8.0-8.8.
• Nut for fastening the silent block to the crossmember: 4.3-4.8.
• Gearbox secondary shaft rear end nut: 10.0.
• Nut for bolt securing rear cover to gearbox housing: 2.5.
• Nut of the bolt securing the suspension bracket support to the gearbox housing: 2.0-2.5.
• Drain plug: 5.0±1.0.
• reverse intermediate gear axle mounting bolt (for cars with 6-cylinder engines): 4,0—5,0.