Balance Shaft Belt: Adjustments

CHECKING BALANCE BELT TENSION

NOTE: In order to perform this operation, Porsche special tool P9201 is needed, Tools and Equipment

CAUTION: Do not check or adjust drive-belt tension unless engine is cold (at room temperature).

1. Unbolt and remove engine underguard.
2. Remove Poly-rib belt and servopump belt.

Loosening Linkage:

CAUTION: Always first loosen hex bolts of linkage slightly before unscrewing locknuts.

3. Remove breather hose at top and remove drive-belt cover.

Slackening Pulley:

4. Slacken pulley so that it no longer tensions drive belt.

TDC Mark:

5a. Turn crankshaft clockwise until TDC mark on camshaft sprocket is aligned with mark on drive-belt cover.
b. TDC mark on flywheel must also be aligned.

Aligning Sprockets:

6. Check basic position of balance-shaft sprockets. Marks on sprockets must be aligned with marks on rear drive-belt cover.

7. Prepare Special Tool 9201 for testing. Pull lockpin from Special Tool and push gage pin opposite lockpin out as far as it will go. Align telltale and measuring needles.

Checking Belt Tension:

8. Slide Special Tool on to belt. Press measuring key (arrowed) in slowly until lockpin is heard to engage and read the value from dial gage.
Specified value (new or used belt): 2.7 +/- 0.3 scale gradations. If necessary, correct belt tension.

NOTE: To exclude errors in reading the gage always align telltale needle and measuring needle once the lockpin is engaged (turn anticlockwise).

ADJUSTING BALANCE BELT TENSION

Changing Belt Tension:

9. Turn tensioning roller clockwise to increase tension. Turn anti-clockwise to slacken. Tighten hex nut to 45 Nm (33 ft lb) while countering.

Setting Pulley Pretension:

Balance Shaft Belt:

10. After adjusting drive-belt tension, adjust idler pulley. Using Special Tool 9207 or feeler gage 0.5 mm (0.020 in) set pulley so that there is a clearance of 0.5 mm between belt and pulley at the lower balance shaft when o to 1 mm pretension is applied to upper run of toothed belt. Tighten pulley in this position. If correct clearance cannot be reached, turn pulley through 180°C and repeat adjustment. Tighten hex nut to 45 Nm (33 ft lb)while countering.

11. Install Poly-rib belt, servopump belt and adjust.

CAUTION: Slides must make full-surface with contact belt. While measuring, do not allow the Special Tool to turn or move on the belt.