SEAT Workshop Service and Repair Manuals

Total disc thickness „Stotal“ („S3“ + „S4“): determine (Setting preload of tapered roller bearings for pinion shaft) l  Differential removed → Chapter l  Outer ring of the double conical roller bearing for the removed crown wheel → Fig.

–  Press tapered roller bearing outer race for pinion shaft into gearbox housing without shims.

–  Press in tapered roller bearing outer race for pinion shaft with shim „S4*“ (thickness 1.01 mm) into bearing housing.   Note For measurement purposes a shim „S4“ with a thickness of 1.01 mm is inserted provisionally. This is referred to in the following as „S4*“. „S4*“ is exchanged with the final shim „S4“ after determining measured value „e“.

–  Secure gearbox housing onto gearbox support -VW 353- with bolts -arrows-.

–  Press tapered roller bearing inner race -1- onto pinion shaft and secure → Fig.. –  Fit selector gears and locking collar for 1st and 2nd gears -2- → Chapter. –  Press tapered roller bearing inner race -3- onto pinion shaft → Fig.. –  Insert completely assembled pinion shaft in gearbox housing. –  Fit bearing housing and gearbox cover with the 4 dowel sleeves and tighten bolts to 35 Nm. –  Turn gearbox so that the gearbox cover points downwards.

–  Press down on face of pinion shaft with transmission removal lever -VW 296- until the tapered bearing outer race contacts the bearing housing. –  Maintain pressure and rotate pinion shaft 5 turns in both directions to seat tapered roller bearing.

–  Fit dial gauge (3 mm measuring range) with 30 mm dial gauge extension to gearbox housing. –  Adjust the dial gauge to „0“ with a pre-tension of 1 mm. The dial gauge extension must contact the machined surface on the face of the pinion.

–  Turn gearbox so that the gearbox cover points upwards. –  Rotate pinion shaft 5 turns in each direction so that the tapered roller bearing seats properly. Otherwise the result of the measurement will be incorrect. –  Read the play measured on the gauge and take note. t  Measurement in example: 0.46 mm.   Note If the measuring procedure needs to be repeated, the pinion shaft must first be rotated 5 turns in each direction again so that the tapered roller bearing seats properly. Preload dial gauge to 1 mm and set to „0“ again. Formula: Formula: „Stotal“ = „S4*“ + measured value + bearing preload

Example:
	Inserted shim „S4*“	1.01 mm
+	Measured value (example)	0.46 mm
+	Bearing preload (constant value)	0.12 mm
=	Total shim thickness „Stot“ for „S3“ plus „S4“	1.59 mm

Determining thickness of shim „S3*“ Formula: „S3*“ = „Stotal“ – „S4*“

Example:
	Total shim thickness „Stot“ for „S3“ plus „S4“	1.59 mm
-	Inserted shim „S4*“	1.01 mm
=	Thickness of shim „S3*“	0.58 mm

–  Pull tapered roller bearing outer race out of gearbox housing → Fig. –  Fit shim „S3*“ in gearbox housing and install outer race again → Item. –  Insert completely assembled pinion shaft into gearbox housing again. –  Fit bearing housing and gearbox cover with the 4 dowel sleeves and tighten bolts to 35 Nm. –  Turn pinion shaft five turns in both directions so that the tapered roller bearings settle.

–  Attach assembly device -VW 792- to gearbox housing; when doing so, insert an M12 nut -A- between assembly device -VW 792- and gearbox housing. –  Fit universal dial gauge bracket -VW 387- with dial gauge and 30 mm dial gauge extension. –  Apply dial gauge extension exactly at centre of intersection of ribs on gearbox cover -arrow-. –  Put the dial gauge (3 mm range) to „0“ with a pretension of 1 mm. –  Loosen gearbox cover bolts and turn pinion shaft several times. –  If the correct shims have been selected the dial gauge will now indicate the following value: t  0.06 ... 0.12 mm –  Tighten gearbox cover bolts again to 35 Nm. –  Detach measuring equipment. –  Turn pinion shaft five turns in both directions so that the tapered roller bearings settle. Determining dimension „e“   Note Measurement „e“ is required to determine the final shim thickness of „S3“ and „S4“.

–  Set adjustment rings of universal measuring tool -VW 385/1- to the following values: t  Dimension -a- = 45 mm t  Dimension -b- = 75 mm

–  Assemble universal measuring tool -VW 385/1- as illustrated: t  Dial gauge extension -VW 385/15-, 6.5 mm long t  Master gauge -VW 385/30- –  Set master gauge -VW 385/30- to Ro = 59.65 mm and fit onto measuring tool. –  Put the dial gauge (3 mm range) to „0“ with a pretension of 2 mm.

–  Place end measuring plate on face of pinion shaft.   Note Ensure plate contact surface fits exactly and is free of oil.

–  Remove master gauge and insert measuring tool into housing. t  The dial gauge faces towards the final drive cover –  Fit cover for final drive and tighten 4 bolts to 20 Nm. –  Using the adjustable ring, pull the second centring disc -VW 385/36- out as far as possible so that the measuring tool can still just be turned by hand.

–  Turn measuring tool until tip of dial gauge touches end measuring plate on face of pinion gear, and measure maximum deflection (return point). t  Measurement value in the following example: „e“ = 0.17 mm (red number band)   Note Then (after removing universal measuring tool), check once again that the dial gauge indicates „0“ with 2 mm pre-tension when master gauge -VW 385/30- is in place.