Rear torsion bar setting

If torsion bars are replaced or reset, it is strongly recommended that the vehicle balance/weight be checked at all four wheels using suitable wheel-load floor scales. See 440 Wheels, Tires, Alignment for more information.

The initial position of each rear torsion bar is set by measuring torsion plate inclination in its unloaded position.

^ With car close to ground level, use floor jack under trailing arm to relieve suspension load on shock absorber. (Brake backing plate shown removed for clarity.)

• Remove rear shock absorber lower mounting bolt from trailing arm (arrow).

Porsche special tool P 289 a may be used to hold rear suspension in a compressed position while working on the rear shock absorber bolt.

— Lower and remove floor jack.

Porsche P289


Torsion Bar Trailing Arm


^ Mark torsion plate position to trailing arm by scribing outline around torsion plate. Remove torsion plate fasteners (arrows) and detach trailing arm from torsion plate.

The torsion plate fastener holes are elongated. Mark relative positions of torsion plate, trailing arm and eccentric bolts (A) in order to reassemble suspension close to original alignment setting.


Porsche 911 Torsion Bar

With car still close to ground and torsion plate supported from below using floor jack, raise torsion plate just until plate comes off lower stop (arrow) on torsion bar cover.

^ Loosen 3 torsion bar cover bolts (A) and remove stop bolt and sleeve (B).

— Slowly lower and remove floor jack to unload torsion bar tension.

Porsche 911 Threshold Repair

Using spirit level in special protractor tool 261/1 or equivalent, measure inclination of vehicle body at door sill (measurement A).

Measure inclination of torsion plate (measurement B).

— Combine measurements A and B (add or subtract body inclination measurement) to find value of torsion plate inclination in relation to vehicle body. Record measurement.

Example body inclination (A) -2°

measured torsion plate inclination (B) 342 Actual torsion plate inclination 32°

There are unequal numbers of splined teeth on the inner and outer ends of each torsion bar. This allows for small incremental changes to be made to the torsion plate inclination.

Rear Torsion Bar Variants


198 7-1989

Number of splines Inside Outside

40 44


Smallest possible change in torsion plate inclination



Smallest possible change in vehicle height

Approx. 6.5 mm (0.256 in.)

Approx. 1.4 mm (0.055 in.)

Dixon Commercial Mower Drive Belt


Rear Torsion Bar Specifications


Torsion bar diameter

Torsion bar splines inside/ outside

Torsion plate inclination (see text)


Carrera with gas struts Carrera w/out gas struts Turbo look

24.1 mm 24.1 mm 26 mm

40/44 40/44 40/44

34° 35° 36"


26 mm

40/44 40/44

26 mm

46/47 46/47

32° 34°

— If torsion plate inclination is incorrect:

• Remove torsion bar cover fasteners and slide cover with torsion plate off body.

• Reposition torsion bar in torsion plate and reinstall cover using 3 fasteners.

• Recheck inclination and readjust as necessary.

It may be necessary to try several different positions for inner and outer teeth on the torsion bar to achieve the correct setting.

— Once torsion bar inclination is correct, use floor jack to raise trailing arm/torsion plate just enough to install lower stop bolt with spacer.

• Tighten all four torsion bar cover mounting bolts.

Tightening Torque

• Torsion bar cover to body (M10) 47 Nm (34 ft-lb)

— Remainder of installation is reverse of removal.

• Reset rear wheel alignment and check ride height as described in 440 Wheels, Tires, Alignment.

Replacement and/or removal of the torsion plate or torsion bar disturbs the rear wheel alignment settings and also affects vehicle ride height, which directly influences vehicle stability. If ride height is changed, it is strongly recommended that the vehicle balance/weight be checked at all four wheels using suitable wheel-load floor scales. See 440 Wheels, Tires, Alignment for more information.

Tightening torques

• Rear shock to trailing arm (M14) 125 Nm (92 ft-lb)

• Torsion plate to trailing arm (eccentric) . 85 Nm (61 ft-lb)

• Torsion plate to trailing arm (M12 bolt). 120 Nm (87 ft-lb)

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