SEAT Workshop Service and Repair Manuals

Main shaft: dismounting and assembling

t	If it is necessary, assemble new pinions, consult section for Identification initials, assignation of groups, reductions, amounts for filling Group → Chapter.

t	The main shaft must be adjusted whenever parts have been replaced that may affect the position of the tapered roller bearings. Consult the Adjustment Chart → Chapter.

Assembly Chart

1 -	Clutch casing

2 -	Outer track, tapered roller bearings

q	Dismounting → Fig.

q	Assembling → Fig.

3 -	Tapered roller bearing

q	Dismounting → Fig.

q	Assembling → Fig.

4 -	Main shaft

q	Adjusting the main shaft → Chapter

5 -	3rd gear pinion

q	Dismounting → Fig.

q	Assembling → Fig.

q	Position for assembly: the collar must remain facing towards the 4th gear pinion.

6 -	Safety ring

q	Use tool -A-81124- for extracting the safety ring.

q	Always replace

7 -	4th gear pinion

q	Dismount it together with the tapered roller bearing → Item, the stop washer → Item and the sleeve for the needle bearing → Item, → Fig.

q	Assembling → Fig.

q	Position for assembly: the collar must remain facing towards the 3rd gear pinion.

8 -	Tapered roller bearing

q	Dismount it together with the 4th gear pinion → Item, the stop washer → Item and the sleeve for the needle bearing → Item, → Fig.

q	Assembling → Fig.

9 -	Stop washer

10 -	Outer track, tapered roller bearing

q	Dismounting → Fig.

q	Assembling → Fig.

11 -	Adjustment washer

q	For the main shaft

q	Finding the thickness → Chapter

12 -	Gearbox casing

13 -	Sleeve for needle bearing

q	Dismount together with the 4th gear pinion → Item, the tapered roller bearing → Item and the stop washer → Item, → Fig.

q	Before assembling it, put the stop washer into place → Item

q	Assembling → Fig.

14 -	Needle bearing

15 -	5th gear pinion

q	Dismount it together with the 5th gear synchroniser unit → Chapter

16 -	5th gear synchroniser ring

q	Check the wear → Chapter

17 -

Spring

q	Position for assembly → Fig.

18 -	Blocking pins

q	Assembling → Fig.

19 -	Synchronised boss

q	Assembling → Fig.

20 -	Movable sleeve for 5th gear

q	Assembling → Fig.

21 -	Plate spring

q	Position for assembly: the concave side must remain facing towards the 5th gear pinion → Chapter

22 -	Bolt for attaching the 5th gear pinion. 80 Nm

q	The head of the bolt has a slot for housing the plate spring → Item

q	Assembly → Chapter

Special tools and workshop equipment required

t	Case for extractors for gearboxes -U-40100-

t	Gearbox repair case -U-40200-

t	Pliers for opening elastic rings -A-81124-

Dismounting the outer track of the tapered roller bearing –  Dismounting the outer track of the tapered roller bearing from the main shaft in the clutch casing using tool -U-40200/20-.

Assembling the outer track of the tapered roller bearing –  Assemble the outer track of the tapered roller bearing for the main shaft in the clutch casing, using tool -U-40200/10- and tool -U-40200/11-.

Dismounting the tapered roller bearing –  Place the tool -U-40100/4- between the bearing and the main shaft pinion. –  Place the main shaft on tool -U-40100/4-, as shown on the drawing. Work the press in order to extract the bearing.

Assembling the tapered roller bearing –  Assemble the bearing over the main axle using tool -U-40100/3- with the help of a press. –  Place the main shaft with the tapered bearing over the base of the tool -U-40100/3-, as shown in the drawing. Operate the press until the bearing is mounted in its position.

Dismounting the 4th gear pinion, the tapered roller bearing, the stop washer and the sleeve for the needle bearing The 4th gear pinion is dismounted together with the tapered roller bearing, the stop washer and the sleeve for the needle bearing. –  Assemble the tool -U-40100/3- in the main shaft, underneath the 4th gear pinion. –  Put the main shaft and the tool -U-40100/3- over the press as shown in the drawing. –  Work the press until the tapered roller bearing and the 4th gear pinion and the stop washer remain outside of the coupling.

Dismounting the 3rd gear pinion –  Assemble the tool -U-40100/3- in the main shaft, underneath the 3rd gear pinion. –  Put the main shaft and the tool -U-40100/3- over the press as shown in the drawing. –  Work the press until the 3rd gear pinion is removed from the main shaft.

Assembling the 3rd gear pinion –  Assemble the tool -U-40100/3- underneath the 3rd gear pinion. –  Place the tool -U-40100/3- with the pinion in a press, as shown in the drawing. Assemble the main shaft inside the pinion. The cogs of the pinion and the main shaft should match. Position for assembly: The collar of the pinion should remain facing towards the 4th gear pinion. –  Work the press until the pinion remains assembled in its position.

Assembling the 4th gear pinion –  Assemble the tool-U-40100/3- underneath the 4th gear pinion. –  Place the tool -U-40100/3- with the 4th gear pinion in a press, as shown in the drawing . Assemble the main shaft inside the pinion. The cogs of the pinion and the main shaft should match. Position for assembly: The collar of the pinion should remain facing towards the 3rd gear pinion. –  Work the press until the pinion remains assembled in its position.

Assembling the tapered roller bearing –  Assemble the tool -U-40100/3- over the base of the 2nd gear pinion and the main axle. –  Put the stop washer into place before placing the sleeve for the needle bearing. –  Put the tool -U-40100/3- on the press as is shown in the drawing. –  Fit in the tapered roller bearing, using tool -U-40200/19-. Work the press until the bearing is assembled in its position.

Assembling the sleeve for the needle bearing –  Assemble the tool-U-40100/3- over the base of the 2nd gear pinion and the main axle. –  Place the shaft of the main axle with the 2nd gear pinion and tools -U-40100/3- and -U-40300/8- on a press as is shown in the drawing. –  Work the press until the sleeve is mounted in its position.

Dismounting the outer track of the tapered roller bearing –  Extract the outer track of the tapered roller bearing of the main shaft in the gearbox casing using tool -U-40200/10-.

Assembling the outer track of the tapered roller bearing –  Assemble the outer track of the tapered roller bearing for the main shaft in the gearbox casing using tool -U-40200/10- and tool -U-40200/11-.   Note! If the main shaft has been adjusted, the stop washer must be assembled before assembling the outer track for the tapered roller bearing.

Assembling the 5th gear synchroniser unit –  Assemble the 5th gear synchroniser unit by carrying out the following steps: –  Place the movable sleeve -2- over the synchroniser sleeve -3- in such a way that the trimmings coincide -Afor housing the block pins -4- for both components and that the pointed cogs of the movable sleeve are situated in the same direction as the most pronounced edge -B-of the bushing. –  Assemble the blocking pins -4- and fix them in place with the springs -1- spreading them out 120º away from each other and under the projections of the blocking pins.

Assemble the springs in the 5th gear synchroniser unit –  Check that the pointed cogs -A- of the movable sleeve are facing in the same direction as the most pronounced boss -B- of the bushing. –  Check that the blocking pins are assembled correctly → Fig.. –  Place the springs spread out 120º from each other, underneath the projections -C- of the blocking pins. The bent ends of the springs -arrows- must be located outside of the pins for blocking.