Work Procedure

FIGURE I:

The operating instructions for the hardness tester are included with each instrument, however, below is a simplified version of these instructions:

- Remove both rear wheels
- Clean measuring area on spring plate (figure 1)

FIGUREII:

Install measuring instrument on spring plate with clamping bolt. Tighten bolt slightly, approximately 10 N-m or 7 ft. lbs. (figure 2). Make sure that lever is in the vertical position, pointing upwards.

NOTE: Always operate lever slowly!

- Turn lever in direction of dial gauge to the horizontal position.
- Turn knurling ring on dial gauge until black value 100 (arrow) is lined up with the pointer. The small pointer must be pointing to pointion "A". If this is not the case, loosen locking ring under the dial gauge and correct accordingly, then position large pointer back to 100.
- Turn lever downwards 90~ (figure 2) (deflection of pointer is not important!)
- Leave lever in this position for approximately 10 seconds. Move lever back 90~ - lever is now in the horizontal position.
- Read off measured value on black scale.
- Replace spring plate only if measured value is less than 15 scale units.
Before removing the hardness, tester, the lever must be put back to the upper vertical position, so that the diamond is not damaged.

NOTE: If an error occurs during measuring procedure, the tester must be installed on a different spot and the complete procedure repeated.

- Repeat the same procedure on the other side spring plate.

- Mark area inspected with a red paint dot or mark with the marker included in the hardness tester kit to indicate inspection.

- Reinstall rear wheel and torque lug nuts to:

Steel lug bolts, M14 x 1.5 mm with 24 mm shoulder = 110 N-m or 80 ft. lbs.

All other steel lug bolts or aluminum lug nuts to: 130 N-m or 94 ft. lbs.

- In case of spring plate replacement, proceed in accordance witht he workshop manual for Model 924, Volume III, pages 42-21 to 42-24 and 42-8 to 42-8c.

NOTES:

. . . In case of the Model 924 Turbo, the gearbox must be supported as shown in the illustration at the top of page 42-21 of the workshop manual.

. . . The spring plate adjustment values have changed from those outlined in the workshop manual. The current values are:

Inclination of spring plate - 19~ 924
- 24~ 30' 924 Turbo, 944

. . . The correct torsion bar diameter for all cars is 23.5 mm.

. . . We recommend that the position of the old spring plate be marked before removal. Install new spring plate in that position as our experience has shown that the vehicles have settled in the meantime.

. . . The function and calibration of the measuring instrument can be checked using the enclosed test plate. The same procedures should be used as for the vehicles. The indicator must read between 26-31 scale units.