Mercedes-Benz E-Class Owner's Bible (1986-1995), Update

Abstract: How to replace polyribbed belt on Mercedes-Benz E-class (W124) with M103 and M104 engines


Applies to: Mercedes-Benz E-Class (W124) 1986 - 1995 with M103 and M104 gasoline engines


This article is supplemental information to the Bentley Mercedes-Benz E-Class Owner's Bible , Chapter 3 Maintenance  pages 97 - 101 regarding conflicting belt routing diagrams.Changes are marked in red.

Chapter 3 - Maintenance

Polyribbed belt replacing, pages 97-102

M103 engine

  • Loosen fan shroud from its mounting points and place it back up on fan.
  • Lock main fan pulley by inserting special tool 103 589 00 40 00 into hole in hub (arrow).

  • Using special tools 103 589 01 09 00 and 001 589 72 21 00, remove hex socket screw in center of fan hub and remove viscous fan / clutch assembly along with shroud.
  • Loosen clamping bolt (arrow) at least ½ turn.

Engine without air conditioning shown.

- Using tension adjusting screw (arrow), release tension on belt tensioning device. This will free up belt.

  • Remove belt.
  • Check all pulleys for damage. Check belt tensioning device for play. Replace if required.
  • Using tension adjusting screw, move belt tensioner indicator (A) to left-most mark (as viewed from driver seat). B is clamping bolt.

  • Install new belt as shown in diagram.

Engine with air conditioning shown.

- Using tension adjusting screw, adjust tension pointer so it is at 7th mark on indexed tensioner (arrow) or left-most mark on non-indexed tensioner. Tighten clamping bolt.


Tightening torque
Belt tensioner clamping bolt.........75 Nm (55 ft-lb)


  • Check belt routing to make sure it is correct.
  • Reinstall viscous fan clutch and fan shroud.
  • Using counterholding tool 103 589 00 40 00, tighten viscous fan to fan hub.

Tightening torque
Viscous fan to fan hub.........45 Nm (33 ft-lb)


M104 engine

  • Fan shroud for M104 engine is two-piece unit. To remove rear portion for belt changing, remove pin (A) and rotate rear section (B) to left to remove.

  • Loosen clamping screw (A) ½ turn.

  • Loosen tension adjuster (arrow) until belt can be removed.

  • Check all pulleys for damage. Check belt tensioning device for play and replace if required.
  • Install new belt as shown in diagram.

  • Using tensioning adjustment screw, move pointer on belt tensioner to left-most position (A) as viewed from driver's seat. Turning tensioner clockwise, tighten until pointer aligns with right most-mark (B).

  • Check seating of belt in all pulleys.
  • Tighten clamping bolt.

Tightening torque
Belt tensioner clamping bolt..........75 Nm (55 ft-lb


  • Install fan shroud in reverse order of removal.

M119 engine

  • 400E and 500E fan shroud is a two piece unit consisting of upper and lower shrouds. Remove upper shroud.
  • Loosen clamping bolt (A) and loosen tensioning screw (B) in a counterclockwise direction until tensioner is loose enough to remove belt.
  • Check all pulleys for damage. Check belt tensioning device for play and replace if required.
  • Install new belt as shown in diagram.

  • Using tensioning screw, adjust belt tensioner pointer so it is pointing to right-most mark (top in picture, side view of belt tensioner).

  • Turn tensioning screw clockwise until pointer is in center position.

  • Check seating of belt in all pulleys.
  • Tighten clamping bolt.

Tightening torque
Belt tensioner clamping bolt..........100 Nm (74 ft-lb)


  • Install fan shroud in reverse order of removal.
Mercedes-Benz E-Class (W124) Owner's Bibleâ„¢: 1986-1995

 

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