928 S V8-4957cc 5.0L (1985)
9. Press down tester on housing (arrow 1) slowly until gauge tip resting on air pump bracket (arrow 2) engages.
Read test value without tension in tester, i.e. tester must be kept horizontal to the toothed belt. Tester must not rest on the plastic cover.
Sliding shoes must rest on belt with their entire surface. Special tool must not be turned or moved on the belt during the entire checking
procedures.
Note: The drag needle must always be placed on the gauge needle after the lock pin has engaged to exclude erroneous gauge readings (turn
anticlockwise).
10. Pull out lock pin to have gauge tip disengage.
Important: Engine must be turned to position described in point 5 for this test. Repeat test one or two for checking! Adjusting value: 5.0 + 0.3.
Correct belt tightness if necessary.
Adjusting
The toothed belt adjusting screw is located on bottom of engine at front righthand side.
Loosen lock nut of adjusting screw and turn adjusting screw until correct toothed belt tightness is reached. Tighten lock nut. Turn engine two more
turns and recheck belt tightness.
Screw tightened - belt tightened.
Screw loosened - belt loosened
Note: Never turn engine anticlockwise, because toothed belt could jump off if tightness were insufficient.