SEAT Workshop Service and Repair Manuals

Total disc thickness „Stotal“ („S1“ + „S2“): determine (Setting preload of tapered roller bearings for differential) l  Pinion shaft removed –  Remove flange shaft oil seals –  Remove tapered roller bearing outer races for differential and take out shims → Chapter.

–  Drive outer race for tapered roller bearing (right-side) with shim „S2“ into gearbox housing. For measurement purposes use a 1.30 mm thick „S2*“ shim (or 2 shims of 0.65 mm).   Note For measurement purposes a 1.30 mm thick shim „S2“ is inserted provisionally. This is referred to in the following as „S2*“. „S2*“ is exchanged with the final shim „S2“ after determining backlash.

–  Press outer race for tapered roller bearing (left-side) without shim „S1“ into cover for final drive. –  Insert differential in gearbox housing. The crown wheel is positioned on the left-hand side (same side as cover for final drive). –  Fit cover for final drive with 4 bolts (20 Nm). –  Turn gearbox so that cover for final drive points upwards. –  Turn differential five turns in both directions so that the tapered roller bearings settle. –  Place measuring plate -VW 385/17- on differential.

–  Set up measuring tool using 30 mm extension. –  Set dial gauge (3 mm measuring range) -A- to „0“ with 2 mm preload.   Note Tip of dial gauge must be located at centre of differential. –  Raise differential without turning, read clearance off dial gauge and note down. l  Measurement value in the following example: 0.62 mm   Note

t  Secure special tools -VW 521/4- and -VW 521/12- on right of differential (gearbox side) to lift differential. t  If the measurement has to be repeated, the differential must again first be turned 5 turns in each direction to settle the tapered roller bearings. Formula: Formula: „Stotal“ = „S2*“ + measured value + bearing preload

Example:
	Inserted shim(s) „S2*“	1.30 mm
+	Average value	0.62 mm
+	Bearing preload (constant value)	0.25 mm
=	Total shim thickness „Stot“ for „S1“ plus „S2“	2.17 mm

Determining thickness of shim „S1*“   Note t  Provisional shim „S1*“ is replaced with final shim „S1“ after determining backlash. t  Total shim thickness „Stotal“ remains unchanged. Formula: „S1*“ = „Stotal“ – „S2*“

Example:
	Total shim thickness „Stot“ for „S1“ plus „S2“	2.17 mm
-	Inserted shim(s) „S2*“	1.30 mm
=	Thickness of shim „S1*“	0.87 mm

Refer to → Spare parts catalogue for required shims.