Repair of the 5DYG/5DYM26 manual transmission

Dismantling the gearbox 5DYG/5DYM26 (GAZelle NEXT)

Dismantling the gearbox 5DYG/5DYM26 (GAZelle NEXT)

In this article we look at dismantling the 5DYG/5DYM26 gearbox.

General view and components

The gearbox comprises the following main components:

General view of the gearbox with the main components indicated — Main components: 1 — clutch housing; 2 — input shaft; 3 — front cover; 4 — third-fourth gear synchromesh sleeve; 5 — third gear; 6 — second gear; 7 — first-second gear synchromesh sleeve; 8 — first gear; 9 — fifth gear; 10 — gear lever cover; 11 — gear lever; 12 — output shaft; 13 — odometer; 14 — fifth gear synchromesh sleeve; 15 — rear gearbox housing; 16 — fifth gear intermediate gear; 17 — intermediate plate; 18 — reverse intermediate gear; 19 — reverse gear shaft; 20 — gearbox shroud; 21 — layshaft

Dismantling the gearbox

Step-by-step instructions

Removal of the external components:

remove the clutch release bearing;
remove the clutch release fork;
remove the clutch housing;
remove the front cover components;
withdraw the input shaft;
remove the front circlip of the layshaft bearing;
remove the control lever assembly;
remove the gearbox cover with the gearshift mechanism;
remove the positioning mechanism components;
withdraw the rear housing assembly (steel ball, spring and gearshift shaft securing bolt);
remove the gearbox shroud.

Removal of the gearshift mechanism components

unscrew the threaded securing plug of each gearshift fork shaft;

Threaded securing plugs of the gearshift fork shafts — We unscrew the threaded securing plug of each gearshift fork shaft

remove the spring and steel ball;
remove the retaining pin of each gearshift fork;
withdraw the elastic cylindrical pin;

Retaining pins and elastic cylindrical pin of the forks — We remove the retaining pin of each fork and withdraw the elastic cylindrical pin

remove the securing screws and circlip (use a drift less than 5 mm in diameter to remove the pins).

Removal of the gearshift forks

remove the shaft of the fifth gear/reverse gear fork;

Shaft of the fifth gear and reverse gear fork — We remove the shaft of the fifth gear/reverse gear fork

remove the shaft of the fifth gear fork;
remove the fifth gear fork.

Dismantling the fifth gear/reverse gear engagement mechanism

withdraw the steel balls of the detent from the guide block;
remove the fifth gear/reverse gear engagement guide block;

Fifth gear/reverse gear engagement guide block — We remove the fifth gear/reverse gear engagement guide block

remove the reverse gear fork shaft and the reverse gear engagement block;
withdraw the guide rod of the reverse gear engagement lockout mechanism.

Dismantling the lockout mechanisms

withdraw the lockout mechanism pin;
remove the first/second gear fork shaft;

First/second gear fork shaft and lockout pin — We remove the first/second gear fork shaft after withdrawing the lockout pin

withdraw the guide rod of the first/second gear lockout mechanism;
repeat for the third/fourth gear fork shaft and the first/second and third/fourth gear forks.

Removal of the layshaft components

remove the rear circlip of the layshaft;
remove the fifth gear connecting gear;
withdraw the fifth gear;

Fifth gear and layshaft needle bearing — We withdraw the fifth gear and its needle bearing

remove the fifth gear needle bearing;
remove the thrust washer and steel ball (6.35 mm dia.).

Dismantling the odometer and output shaft

remove the circlip of the odometer drive gear;
remove the odometer drive gear;

Odometer drive gear and circlip — We remove the circlip and the odometer drive gear

remove the baffle of the output shaft rear bearing;
remove the circlip of the output shaft rear bearing.

Removal of the reverse gear components

remove the bracket of the reverse gear rocking lever;
remove the plate of the reverse intermediate gear shaft;

Lever bracket and plate of the reverse intermediate gear shaft — We remove the rocking lever bracket and the plate of the reverse intermediate gear shaft

withdraw the reverse intermediate gear and the intermediate gear shaft.

Removal of the layshaft and input shaft

remove the layshaft assembly and its bearing;

Layshaft assembly with its bearing — We remove the layshaft assembly and its bearing

remove the input shaft assembly and the third/fourth gear synchromesh ring (take care not to lose the input shaft needle bearing).

Removal of the output shaft

Output shaft assembly — We remove the output shaft assembly

remove the output shaft assembly.

We will look at assembling the gearbox in the next article.