16. Tip: 240GD: The clutch: BM 46031017

last updated 2010, 04.01. (2005, 27.06.) Copyright Dr. Hans Hehl, translated by Klaus Hold ( www.gwagen.de)

Impressum see TMG Paragraph 5

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All work on the G requires special knowledge, competency, special tools and the strength to not overestimate your own abilities, or better go to the service dealer for repair or maintenance. This I did and used a mechanic service to replace gearbox and clutch. All information here at the best knowledge, but without guarantee! Data is for 240GD My 10/1979, BM 46031017000518


1. test clutch clearance:
2. recieving cylinder overhaul:
3. transmitting cylinder overhaul:
4. clutch replacement:
5. clutch bearing:

The clutch is operated with normal brake fluid DOT4. There is one hydraulic transmitting cylinder and one receiving cylinder. The brake fluid should be replaced every 2-3 years.

1. Checking clutch slack / clearance:

The clutch clearance can not be detected from outside easily. Reason: The contact pressure increases with reduction of the clutch shoe (the clutch will not fade).
For the first G models the worn out status can only be detected indirect at the recieving cylinder with a control gauge (W 115 589 07 23 00 - 4,65 Euro inkl. Tax). The control gauge will be inserted in the slot of the plastic base. If one can't see the cut out at the gauge, the clutch is still OK. If one can see the cut outs, the clutch needs to be replaced.

control gauge plastic base clutch okey
The grid under the gauge is usable for a rebuild. The plastic base is available in two styles: A 4602511580 - 1,80 Euro incl. Tax and Nr. A 1152510080 - 1,11 Euro incl. Tax.
2. Clutch: slave cylinder / recieving cylinder repair: top back to the top

a) Remove: After the fluid level in the reservoir has been reduced more and more the receiving cylinder needed to be repaired. First remove the fluid from the reservoir. Remove the filter by moving the filter to the side and turn it out. Put a hose on the bleeding nipple, open the nipple (7 mm hex tool) and remove the brake fluid. Remove the pipe at the receiving cylinder (12mm). Remove 2 screws that keep the cylinder in place (13mm). Attention: keep an eye on the plastic base between the gearbox and the cylinder.

Remove the lock washer with a screwdriver and remove the stud with the grommet. In the cylinder the piston with the pressure spring is located. It can be removed with some knocking at the cylinder or with some air pressure. The sealing of the old piston was hardened. Remove the grommet from the pressure stud.

b) Assembly: The inside wall of the cylinder must be fully smooth. Eventually remove the light rust with fine sandpaper (grain size 600). If rust rills exist, the cylinder has to be renewed. With some brake piston paste you can grease the cylinder a little bit and ease the assembly. The piston has been redesigned meanwhile.

Insert the spring and then the pressure piston with the tip first into the cylinder. Put in the piston smoothly and constantly to not damage the rubber edge. On the new grommet insert the holding ring and then put it onto the pressure stud (see picture).

Put the receiving cylinder into a bench vice, insert grommet with pressure stud and insert the tool washer (teeth pointing upwards) transversal on one side and insert it with a screw driver on the other side (secure it on all sides). The correct assembly is shown in the pictures below.

Now the receiving cylinder can be mounted. The plastic base need to point toward the bell housing. Attach the pipe and refill the reservoir with new fluid. The bleeding is best with some air pressure (see tip: bleeding.) Step on the clutch pedal to help remove air.
Pressure sleeve FAG H2336, the receiving cylinder has a bore diameter 23,8 mm.
Repair kit receiving cylinder: A 0002901111 - 23,78 Euro inkl. Tax
Receiving cylinder: A 0002957607 - 86,94 Euro inkl. Tax
Teile Nehmerzylinder Druckkolben Teile Nehmerzylinder
3. Overhaul the master cylinder / transmitting cylinder: top back to the top

After the removal of the transmitting cylinder remove the wire bracket in front of the washer (green arrow, picture 2), with a screwdriver. Remove the large washer. Now the 2 parts, which are separated with a brass washer, can be taken out. Best is to use some air pressure (max 1 bar). The inner part consist of a spring with a rubber mushroom. At the other end it has a rubber cap M190 4-18 with a brass washer. The pressure piston uses a normal FAG-sealing H19300. The holes at the pressure pistons must be clear. The grommet has the same FAG-number as the transmitting cylinder H1750.
Geberzylinder Geberzylinder Teile Geberzylinder
The pressure sleeve need to be assembled in position oriented correctly over the piston. Otherwise the pressure can't be generated correct!

transmitting cylinder: A0012958006 - 164,84 Euro incl. Tac
repair kit: A0002901912 - 82,36 Euro inkl.
pressure sleeve: A0002954083 - 5,45 Euro incl. Tax
sealing (reservoir): N007603022102 - 0.73 Euro incl. Tax
Teile Geberzylinder Teile Geberzylinder
4. Replace clutch: top back to the top

This report has been generated regarding a Gearbox change That's because old and new gearboxes are shown.
Gearbox Gearbox Gearbox Gearbox clutch disc pressure plate
Start at DC Driveshaft removed Gearbox removed / clutch Old gearbox Old clutch Old pressure plate
flywheel pressure plate Gearbox Gearbox Gearbox Gearbox
Old bearing in flywheel Old pressure plate Install new clutch install new gearbox bell housing Ready for installation Gearbox installed
5. Release bearing: top back to the top

Also the release bearing will can be changed at the same time (A 000250 51 15 - 39,67 Euro incl. Tax). I have analysed the old release bearing. The bas plate can be removed.
clutch parts release bearing release bearing release bearing release bearing
6. Part list:

clutch disk: A 009 250 23 03 - 161,59 Euro incl. Tax
pressure plate: A 003 250 91 04 80 - 111,36 Euro incl. Tax
release bearing: A 000 250 51 15 - 39,67 Euro incl. Tax
flywheel bearing: A 115 980 01 15 - 22,60 Euro incl. Tax
cover: A 189 031 00 33 - 1,45 Euro incl. Tax
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