Assemble Countershaft

In order to distinguish between these gear wheels, those for diesel vehicles (with the exception of the gear wheels for 1st gear and reverse gear) have a groove (arrow) in the teeth.

Fig 1: Identifying Groove In Gear Wheel For Diesel Powered Vehicles

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

1. 1 -  Clamp the countershaft in a vise with jaw protectors.
   NOTE: Input end uppermost.
2. 2 -  Install 4th gear needle roller bearing (22).
3. 
   
Fig 2: Assembling Countershaft (1 Of 9)
Courtesy of MERCEDES-BENZ OF NORTH AMERICA.
4. 3 -  Install 4th gearwheel (21).
   NOTE: The straight cut teeth must be pointed up.
   NOTE: Risk of mixing up parts:

   The clutch bodies for the 3rd and 4th gears differ in the direction of the tooth tips (arrows):

   • 4th gearclutch body (20): The long side of the point is to the left.
   • 3rd gearclutch body (6): The long side of the point is to the right.

Fig 3: Assembling Countershaft (2 Of 9)
Courtesy of MERCEDES-BENZ OF NORTH AMERICA.
5. 4 -  Install 4th gear clutch body (20).
   NOTE: The outer teeth must point downwards (towards the output end).
6. 5 -  Install the friction ring (19).
   NOTE: The lobes must face upward (towards the input end).
Fig 4: Assembling Countershaft (3 Of 9)
Courtesy of MERCEDES-BENZ OF NORTH AMERICA.
7. 6 -  Install the synchronizer cone ring (18).
   NOTE: The lobes must engage with the recesses (arrow) in the clutch body.
8. 7 -  Install synchronizer ring (17).
   NOTE: The teeth must point downwards (towards the output end).
   NOTE: The lobes in the friction ring must engage in the recesses in the synchronizer ring (17).
   NOTE: Only when required (new synchronizer assembly is supplied as a single unit).
9. 8 -  Assemble new synchronizer assembly:
10. 8.1 -  Lubricate with grease and install 3 blocking pieces (10) in the slider sleeve (11).
    NOTE: The grooves in the blocking piece must face inwards.

    Use appropriate Sleeve. See Figure or Fig 11 .

Fig 5: Assembling Countershaft (4 Of 9)
Courtesy of MERCEDES-BENZ OF NORTH AMERICA.
11. 8.2 -  Push sliding sleeve (11) onto 3rd/4th gear synchronizer body (16).
    NOTE: When pushing on the slider sleeve (11), align it to ensure that the balls (15) will subsequently mesh with the center groove in the slider sleeve teeth (arrow).
12. 8.3 -  Install wide sliders (14), thrust springs (13) and balls (15) in the 3rd/4th gear synchronizer body (16).
    NOTE: The widths of the sliders used for the individual synchronizer bodies vary:

    Slider widths:

    • 1st/2nd gear synchronizer body - Wide sliders (15 mm).
    • 3rd/4th gear synchronizer body - Wide sliders (15 mm).
    • 5th/6th gear synchronizer body - Narrow sliders (9 mm).
    • Reverse gear synchronizer body - Narrow sliders (9 mm).

13. 9 -  Install new 3rd/4th gear synchronizer unit (30) and press on using sleeve.
    NOTE: The orientation groove (top arrow) on the slider sleeve must face upward.
    NOTE: The 3 long lobes (arrow) in the synchronizer ring must engage with the recesses in the synchronizer body.
    NOTE: When pressing on the new synchronizer body, swarf may be produced and this must be removed. Use compressed air to blow off the countershaft.

    Use appropriate Sleeve. See Figure and Fig 11 .

Fig 6: Assembling Countershaft (5 Of 9)
Courtesy of MERCEDES-BENZ OF NORTH AMERICA.
14. 10 -  Determine thickness of circlip (12):
    • Insert test circlip (thickness: 1.5 mm) with insert pliers and push fully downwards (towards the output).
    • Use feeler gauge to measure clearance between test circlip and top edge of groove in the countershaft.
    • Thickness of circlip = Measured value + 1.5 mm (test circlip).
    • Remove test clip using pliers.

    Use Pliers. See Figure.

Fig 7: Assembling Countershaft (6 Of 9)
Courtesy of MERCEDES-BENZ OF NORTH AMERICA.
15. 11 -  Use pliers to install new circlip (12) of the calculated thickness (Graduation: 0.05 mm)
    NOTE: Ensure that the circlip is properly seated.
16. 12 -  Install synchronizer ring (9).
    NOTE: The teeth must point upward (towards the input end). The 3 long lobes in the synchronizer ring (9) must engage with the recesses in the synchronizer body.
17. 13 -  Install synchronizer cone ring (8).
    NOTE: The lobes must face upward (towards the input end).
18. 14 -  Install the friction ring (7).
    NOTE: The lobes in the friction ring must engage in the recesses in the synchronizer ring.
Fig 8: Assembling Countershaft (7 Of 9)
Courtesy of MERCEDES-BENZ OF NORTH AMERICA.
19. 15 -  Install clutch body (6).
    NOTE: The lobes in the synchronizer ring must engage in the recesses in the clutch body (6).
20. 16 -  Install 3rd gear needle bearing (5).
Fig 9: Assembling Countershaft (8 Of 9)
Courtesy of MERCEDES-BENZ OF NORTH AMERICA.
21. 17 -  Install 3rd gear wheel (4).
    NOTE: The straight teeth must face downwards (towards the output end).
22. 18 -  Heat 6th gear fixed gear (3) to approximately 120 °C and press on with sleeve.
    NOTE: The collar must face upward (toward the input end). During the pressing operation hold the 3rd gear wheel in place to prevent the 3rd gear clutch body from jumping out of the synchronizer ring lobe.

    Use appropriate Sleeve. See Figure and Fig 11 .

    Fig 10: Assembling Countershaft (9 Of 9)

    Courtesy of MERCEDES-BENZ OF NORTH AMERICA.
23. 19 -  Heat constant-mesh gear (2) to approximately 120 °C and press on with sleeve.
    NOTE: The collar must face downwards (towards the output end).

    Use appropriate Sleeve. See Figure and Fig 11 .

24. 20 -  Install new circlip (1).
25. 21 -  Release the countershaft from vise.

Fig 11: Sleeve (716 589 02 33 00)

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.