Manual gearbox

Removing and refitting the gearbox

27steps
~162min
4/5difficulty
Done 0 of 27

REMOVAL

  • Disconnect the battery.
  • Remove the driveshaft bolts.
  • Remove the subframe (see relevant operation in chapter 'SUSPENSION-AXLES-GEOMETRY').
  • Remove the catalytic converter clamp (1) and its rubber mount (Fig.2).
  • Remove the gear shift and selector cables.
  • Disconnect the reverse light switch.
  • Lower the engine on the left side until the bolts (2) of the engine mount (3) are accessible (Fig.3).
  • Remove the bolts (4), then the link rods (5) (Fig.2).
  • Remove the bolts (2), then the engine mount (3) (Fig.3).
  • Remove the driveshafts (see relevant operation in chapter 'TRANSMISSIONS').
  • Position a hydraulic support jack with a suitable block of wood under the engine oil sump.
  • Remove the gearbox mount.
  • Disconnect the hose (6) from the breather (7), then remove the clip (8) (Fig.2).

Dépose-repose de la boîte de vitesses
Fig. 2

Dépose-repose de la boîte de vitesses
Fig. 3

  • Remove the starter motor (9) (arrows).
  • Support the gearbox.
  • Remove the gearbox-to-engine mounting bolts (10).
  • Separate the gearbox from the engine and lower it out of the vehicle, taking care with the various harnesses and lines.

INSTALLATION

To refit, reverse the removal procedure, observing the following points:

  • check that the clutch disc is correctly centred,
  • always replace all self-locking nuts or bolts,
  • lightly grease the input shaft splines all around with high-temperature grease,
  • observe the specified tightening torques,
  • check that the gearbox locating sleeves are in place on the engine,
  • check the gearbox oil level,
  • fill and bleed the clutch control,
  • check for leaks with the engine running,
  • if necessary, adjust the gear shift control.

Carters de boîte de vitesses
Gearbox housings

  1. Clutch housing
  2. Gear train housing
  3. Locating sleeve
  4. Seal
  5. Bolt (replace): 2.3 dan.M
  6. Bearings
  7. Oil shields
  8. Bolt: 2 dan.M
  9. Drain plug (replace): 3.5 dan.M
  10. Filler plug (replace): 3.5 dan.M.

Pignonnerie
Gear train

  1. Cylindrical bearing
  2. Input shaft
  3. 6th idler gear
  4. 3rd idler gear
  5. 4th/5th idler gear
  6. Circlips
  7. Output shaft 1st to 4th
  8. Needle bearings
  9. Driven gears
  10. Sliding sleeves
  11. Synchroniser hubs
  12. Synchroniser locking mechanisms
  13. Synchronisers
  14. Synchroniser ring
  15. Washers
  16. Output shaft 5th and 6th
  17. Reverse intermediate shaft.

Test yourself

A quick Mercedes-Benz B-Class quiz: every answer comes with an explanation and a link to the manual page.