Determining total shim thickness "Stotal" for shims "S3" plus "S4"

WARNING: This page is about a different car, the 2008 Audi A4, 2007 Audi A4, 2006 Audi A4, and 2005 Audi A4. However, it is still accessible from the selected car via links, so may be relevant.

(Adjustment of pre-load of tapered roller bearings for pinion shaft with hollow shaft)

Differential removed.

Fig 1: Double Tapered Roller Bearing Inner Race, Large Needle Bearing, Hollow Shaft And Small Needle Bearing

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Press double tapered roller bearing inner race - 1 - onto pinion shaft and secure Pressing on double tapered roller bearing inner race .
Install large needle bearing - 2 -.
Install pinion shaft in hollow shaft - 3 -.

Reassemble hollow shaft with selector gears and tapered roller bearing inner race.

Install small needle bearing - 4 -.

Fig 2: Pressing Tapered Roller Bearing Outer Race For Pinion Shaft Into Transmission Housing Without Shims

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Press double tapered roller bearing outer race for pinion shaft into transmission housing without shims.

Fig 3: Pressing In Tapered Roller Bearing Outer Race For Pinion Shaft With Shim Into Bearing Housing

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Press in tapered roller bearing outer race for pinion shaft/hollow 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".

Fig 4: Securing Transmission Housing Onto Transmission Support VW 353 With Bolts

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Secure transmission housing onto transmission support VW 353 with bolts - arrows -.
Install fully assembled pinion shaft with hollow shaft into transmission housing.
Install bearing housing and transmission cover and tighten bolts to 35Nm.
Turn transmission so that the transmission cover points downward.

Fig 5: Pressing Down On Drive Pinion Head Using Removal Tool VW 296

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Press down on face of pinion shaft with removal tool VW 296 until tapered bearing outer race contacts bearing housing.
While still maintaining pressure, rotate pinion shaft 5turns in each direction in relation to the hollow shaft to settle the double tapered roller bearing.
Rotate pinion shaft together with the hollow shaft 5turns in each direction to settle the hollow shaft tapered roller bearing.
Turn transmission so that the transmission cover points upward.

Turn pinion shaft with hollow shaft five turns in both directions so that the double tapered roller bearing settles. Otherwise the result of the measurement will be incorrect.

Fig 6: Pinion Shaft Clamped Onto Hollow Shaft With A Hose Clip

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Set up measuring tool.
Clamp pinion shaft onto hollow shaft with a hose clip - arrow -.
Set dial gauge (3 mm measuring range) to "0" with 1 mm preload.

Fig 7: Moving Pinion Shaft With Hollow Shaft Up And Down

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Then move pinion shaft - A - with hollow shaft up and down in direction of - arrow -.
Read off play on dial gauge and note reading.

Measurement in example: 0.46 mm

NOTE:

If the measurement has to be repeated, pinion shaft with hollow shaft must first be rotated another 5turns in each direction to settle the double tapered roller bearing. Preload dial gauge to 1 mm and set to "0" again.

Formula: "S_total " = "S₄ *" + measured value + bearing preload

Example:
	Inserted shim "S₄ *"	1.01 mm
+	Measured value (example)	0.46 mm
+	Bearing preload (constant value)	0.15 mm
=	Total shim thickness "S_total " for "S₃ " plus "S₄ "	1.62 mm

Determining thickness of shim "S₃ *"

Formula: "S₃ *" = "S_total " - "S₄ *"

Example:
	Total shim thickness "S_total " for "S₃ " plus "S₄ "	1.62 mm
-	Inserted shim "S₄ *"	1.01 mm
=	Thickness of shim "S₃ *"	0.61 mm

Remove double tapered roller bearing outer race, install shim "S₃ *" in transmission housing and install outer race again.
Re-install fully assembled pinion shaft with hollow shaft into transmission housing.
Install bearing housing and transmission cover and tighten bolts to 35Nm.
To settle the tapered roller bearings: rotate pinion shaft together with hollow shaft 5turns in each direction, then rotate pinion shaft separately in relation to hollow shaft 5turns in each direction.

Fig 8: Determining Thickness Of Shim S3

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Set up measuring tools using dial gauge extension 30 mm - A - ; place nut M12 between VW 792 and transmission housing when securing bolt - arrow - to transmission housing.

NOTE:

Place dial gauge extension - A - onto web in transmission cover.

Set dial gauge (3 mm measuring range) to "0" with 1 mm preload.
Loosen transmission cover bolts and turn pinion shaft several times.
If correct shims have been selected the dial gauge will now indicate the following value:

0.09 to 0.18 mm

Tighten transmission cover bolts again to 35 Nm.
Take down measuring tools.
To settle tapered roller bearings: rotate pinion shaft together with hollow shaft 5turns in each direction, then rotate pinion shaft separately in relation to hollow shaft 5turns in each direction.

Determining dimension "e"

NOTE:

Measurement "e" is required to determine the final shim thickness of "S₃ " and "S₄ ".

Fig 9: Setting Adjusting Rings Of Measuring Bar VW 385/1

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Set adjustment rings of measuring bar VW385/1 to the following values:

Dimension - a - = 45 mm
Dimension - b - = 75 mm

Fig 10: Universal Measuring Tool VW385/1

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Assemble universal measuring tool VW385/1 as illustrated:

Dial gauge extension - VW 385/15 - , 6.5 mm long
Master gauge-adjustable VW385/30

Set master gauge-adjustable VW385/30 to Ro = 59.65 mm and install onto measuring tool.
Set dial gauge (3 mm measuring range) to "0" with 2 mm preload.

Fig 11: Measuring Plate End Placed On Face Of Pinion Shaft

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Place end measuring plate on face of pinion shaft.

NOTE:

Make sure plate contact surface fits exactly and is free of oil.

Fig 12: Identifying Gauge Extension Installed

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Remove master gauge and insert measuring tool into housing.

Install gauge extension - A - (length = 6.5mm).
The dial gauge faces toward final drive cover

Install cover for final drive and tighten 4 bolts to 20 Nm.
Using adjustable ring, pull 2nd centering pad VW385/36 out as far as possible so that the measuring tool can still just be turned by hand.

Fig 13: Turning Measuring Mandrel Until Dial Gauge Plunger Tip Touches End Gauge On Pinion Shaft Head And Measure Maximum Runout

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Turn measuring tool until dial gauge point touches the end measuring plate on pinion shaft head, then measure maximum deflection (return point).

Measurement in following example: "e" = 0.26 mm (in red scale)

NOTE:

Then (after removing universal measuring tool), check once again that the dial gauge indicates "0" with 2mm preload when master gauge VW385/30 is in place.