Reverse Gear Clutch, Selecting Adjusting Discs
Reverse Gear Clutch, Selecting Adjusting Discs
Special tools, testers and auxiliary items required
• Digital Depth Gauge (VAS 6087)
• Digital Caliper, 150 mm (VAS 6335)
• 2x Ruler (T40100)
• Clean and flat measuring surface, for example, the Pre-Tensioning Tool (T10285)
Removing Reverse Gear Clutch
• Refer to => [ Repair Information ] Repair Information.
• Refer to => [ Clean Working Conditions ] Clean Working Conditions.
• Transmission removed and mounted vertically to the engine/transmission holder. Refer to => [ Transmission, Securing in Engine/Transmission Holder ] Transmission, Securing In Engine/Transmission Holder.
- Remove the input shaft. Refer to => [ Input Shaft ] Input Shaft.
- Remove the reverse gear clutch and corrugated spring washer - 1 through 5 - from the transmission.
- Measure the upper adjustment disc - 4 - and lower adjustment disc - 2 - and make a note of it.
• Making a note of the old upper adjustment disc - 4 - and lower adjustment disc - 2 - will be used later when installing new adjusting discs. The measurement must be repeated if the values between the old and new adjustment discs deviate from each other.
Setting the Reverse Gear Clutch by Determining the Adjustment Disc
• The following measurements serve for the determination of the upper adjustment discs - 4 - and lower - 2 - for the setting of the reverse gear clutch.
• For the following measurements, all tool and component surfaces must be completely clean in order to obtain exact values.
1. Measurement from the Input Shaft Cover Contact Surface to the Corrugated Spring Washer Contact Surface - B -:
- Clean surfaces on the transmission housing, completely remove remaining seals.
- Measure from the input shaft cover contact surface to the corrugated spring washer contact surface inside the transmission housing using (VAS 6087).
- Make a note of dimension "B1".
- Repeat measurement on two different points and note the measured values "B2" and "B3".
- Determine and note the average value - B - from the 3 measured values.
Average: B1 + B2 + B3 /3 = dimension - B -
- Make of note of dimension - B -.
Example:
29.0 mm + 28.9 mm + 29.0 mm /3 = 28.97 mm
In the example, dimension - B - = 28.97 mm.
2. Measurement of the Pre-Tension Clutch Package, Determination of Dimension - A -:
• The corrugated spring washer - 2 - is installed under the disc pack to perform measurements.
• Use a clean and flat measuring surface as a backing - 1 -. In the following description, the (T10285) is used.
- Place the corrugated spring washer - A - on the measuring surface - 1 -.
- Then, alternating with the same direction for each lining disc - C - (7 pieces) and place an outer disc - B - (6 pieces) on the corrugated spring washer.
- Allocated all discs cleanly on top of each other.
- Place both (T40100) measuring straight edges over the disc package.
• Through the weight of the (T40100) measuring straight edge, the air is pressed from the discs and the corrugated spring washer is subject to 2.5 kg (pretension).
- Measure with the (VAS 6087) on the working space - 1 - and note the measurement "a1".
• (VAS 6087) must lie flush on both (T40100) when measuring.
- Repeat measurement on the opposite side of the disc package and note the measured value "a2".
- Move the 2 (T40100) by 90°.
- Repeat the measurements and make a note of the values "a3" and "a4".
- Determine and note the average value - a - from the 4 measured values.
Average: a1 + a2 + a3 + a4 /4 = - a -
Determine dimension - A -
- Measure and note the thickness - b - of the (T40100).
The height of the pre-tension clutch package: - a - - - b - = dimension - A -
- Make a note of dimension - A -.
3. Measurement of the Input Shaft Cover Contact Surface on the Pistons of the Reverse Gear Clutch, Dimension - C -:
- Place a clean outer disc - 1 - on the removed input shaft.
• The externally toothed plate - 1 - is placed on the reverse gear clutch piston so that a correct measurement can be performed on the highest position of the piston. The thickness - d - of the outer disc - 1 - will be subtracted later to determine the amount of the piston.
- Measure from the contact surface - 2 - on the input shaft cover to the externally toothed plate - 1 - laid on it with a digital depth gauge (VAS 6087) and then make a note the measurement "D1".
- Repeat the measuring on different point and make a note of dimension "D2".
- Determine and note the average value - D - from the 2 measured values.
Average: D1 + D2 /2 = - D -
- Remove the externally toothed plate from the input shaft and measure the thickness - d - using (VAS 6335).
Determining dimension - C -:
Calculate the measurement of the input shaft cover contact surface on the pistons of the reverse gear clutch, dimension - C -
- D - + - d - = dimension - C -
- Note measurement - C -.
4. Determining the Thickness of Both Adjustment Discs "Etotal ":
- Determining the thickness of the adjustment discs using the following formula using dimensions "A", "B" and "C" and a constant air gap of 3.0 mm:
"B" + "C" - "A" - 3.0 mm = "Etotal "
- Select the lower adjustment disc "E1 " and the upper adjustment disc "E2 " according to the table.
• Allocate adjustment shims, refer to the electronic parts catalog ETKA.
Example:
The following values are found in the example:
• Dimension "A" = 27.98 mm
• Dimension "B" = 28.97 mm
• Dimension "C" = 6.45 mm
• Constant air gap = 3.0 mm
"B" + "C" - "A" - 3.0 mm = "Etotal "
28.97 mm + 6.45 mm - 27.98 mm - 3.0 mm = 4.44 mm
"Etotal " = 4.44 mm
- Lower adjustment disc "E1 " from the table: 1.90 mm
- Upper adjustment disc "E2 " from the table: 2.65 mm
Installing the Reverse Gear Clutch
• As a check, compare the thickness of the new adjustment disc with the thickness of the old adjustment disc performed at the beginning. The measurement must be repeated if the values between the old and new adjustment discs deviate from each other.
• All components must be cleaned thoroughly before inserting.
- Insert the corrugated spring washer - 6 - into the guides - 1 - (3) inside the transmission.
- Insert the lower adjustment disc "E1 " - 2 - into the guides inside the transmission.
- Alternating with the same direction for each lining disc - 3 - and place an externally toothed plate - 5 - into the guides inside the transmission.
- Insert the upper adjustment disc "E2 " - 4 - into the guides inside the transmission.
- Adjust the clutch discs of the reverse clutch, for example, with a straight-edge.
• The grooves must stand exactly in a row.
- Install input shaft. Refer to => [ Input Shaft ] Input Shaft.