Engine - Crankshaft Pulley, Mod. Shock Absorber Install: Overview

85mercedes03 No. 174a
Date: December 1985 (Supersedes W.I.174, June 1985) Grp. 13

Subject: INSTALLATION OF THE BOLTED-ON CRANKSHAFT PULLEY MODIFIED SHOCK ABSORBER FOR BELT TENSIONER AND MODIFIED HYDRAULIC ENGINE MOUNTS MODEL 201.024

NOTE: These parts can also be installed in cars prior to:


Model Transmission Chassis End Number Engine End Number


201.024 Automatic F 068273 007858
Manual F 068346 000905

Figure 1 - Belt Tensioner Modification:

1. Remove fan and fan shroud.

2.. Loosen bolt (827) by approximately 1/2 turn, unscrew tensioning nut (829), remove belt (451), unscrew bolt (827) and remove belt tensioner (803) (Figure 1).

Figure 2 - Belt Tensioner Modification:

NOTE: The following parts must be used from the old tensioner to complete the modified tensioner (Figure 2):

- Dished centering washer (826)
- Tensioning nut (829)
- Shim (828)
- Bolt (827)

3. Engage pull rod (819) to lever (820) as shown in Figure 2.

4. Install the modified belt tensioner by guiding the pull rod (819) through the hole in the top of the front cover (between distributor and P/S pump). Coat the bolt (827) lightly with oil and fasten the tensioner hand tight (Figure 2).

Slide the dished centering washer (826) on the pull rod (819), and install the tensioning nut (829) (Figure 2).

Figure 5 - Modified Assembly:

IMPORTANT: Prior to performing steps 5 thru 9, determine if the modified crankshaft pulley is already installed (Figure 5).

If so, continue with step number 10.

Figure 3 - Crankshaft Lock:

5. Install crankshaft lock, tool number 601 589 02 40 00 (arrow, Figure 3).

Figure 4 - Previous Assembly:

Figure 5 - Modified Assembly:

6. Unscrew bolt (226a) and remove pulley (231) with pulley coupling (263-266) and vibration damper (229) (Figure 4).

NOTE: Transfer the removed washers (228). Replace stretch bolt M 18 x 1, 5 x 75 (226a, Figure 4) with hex. head bolt (226, Figure 5) having the same dimensions (Figure 4).

7. Install new vibration damper. Tighten hex. head bolt (226, Figure 5) to 300 N-m.


8. Install new pulley (231). Tighten Allen screws (234 to 20 N-m (Figure 5).

9. Remove crankshaft lock.

Figure 6 - Second Version Shock Absorber:

10. Install shorter bracket (36, Figure 6).

Tightening torques:

Screw (37) 20 N-m Screws (33a) 8 N-m

11. Attach bracket (33) to oil pan, using M6 x 25 screws (33b). Tighten to 8 N-m (Figure 6).

12. Attach bracket (32) to timing chain cover, using M8 x 70 screws (48). Tighten to 20 N-m (Figure 6).