General Repair Instructions
General repair instructions
The maximum possible care and cleanliness and proper tools are essential to ensure satisfactory and successful transmission repairs. The usual basic safety precautions also naturally apply when carrying out vehicle repairs.
A number of generally valid instructions applicable for the various repair procedures which were previously repeated a number of times at numerous places in this Repair information are summarized here.
Special tools
For a complete list of special tools used in this Repair information
Refer to Special Tools Supplier
Transmission
^ When installing ensure that the dowel sleeves between the engine and transmission are correctly located.
^ When assembling mounting brackets as well as other waxed components the contacts surfaces must be cleaned. Contact surfaces must be free of grease and wax.
^ When changing a transmission or bevel box fill with gear oil.
O-rings, seals, gaskets
^ Always replace O-rings, seals and gaskets.
^ After removing gaskets and seals, always inspect the contact surface on the housing or shaft for burrs resulting from removal or for other signs of damage.
^ Thoroughly clean joint surfaces and apply sealant AMV 188 200 03.
^ Apply sealant uniformly but not too thick.
Before installation:
^ Lightly lubricate radial shaft oil seals at circumference and fill gap between sealing lips (arrow) with a thin layer of sealant G 052 128 A1 before installation.
^ The open side of the oil seals faces toward the side with fluid filling.
After installation:
^ When replacing oil seals, always vary the point at which the sealing lips make contact (use insertion depth tolerances).
^ Checking oil level in manual transmission with bevel box.
Locking devices
^ Do not overstretch circlips.
^ Always replace circlips which have been damaged or over-tensioned.
^ Circlips must locate properly in the groove.
^ Replace roll pins. Position: slit -A- should be in line with the line of force -arrow-.
Bolts and nuts
^ Tighten and loosen bolts and nuts for securing covers and housings in a diagonal sequence.
^ Especially delicate parts, such as clutch pressure plates, must not be distorted.
^ Loosen and tighten nuts and bolts in stages in a diagonal sequence.
^ Tightening torques as specified are for unoiled bolts and nuts.
^ Replace self-locking bolts and nuts.
^ Ensure with screwed connections that the areas of the contact surfaces as well as the visible surfaces of nuts and bolts are rewaxed after assembly, if necessary.
Bearings
^ Install new tapered roller bearings as supplied, do not oil additionally.
^ Install transmission bearings with transmission oil (except for tapered roller bearings).
^ Taper roller bearings fitted to one shaft must be replaced as a set. Use same make of bearings.
^ Heat inner races of taper roller bearings to approximately 100°C before installing. Press in onto stop when installing so there is no axial clearance.
^ Do not interchange outer or inner races of bearings of the same size. The bearings are matched in pairs.
^ Set needle bearings in place with labeled side (thicker metal) toward mandrel.
Shims
^ Measure shims at several points with a micrometer. Tolerance variations make it possible to find the exact shim thickness required.
^ Check for burrs and damage.
^ Only install perfect shims.
Synchronizer rings
^ Do not interchange. When reusing always fit to the same gear.
^ Check for wear and replace if necessary.
^ Coat with gear oil before installing.
Gear wheels
^ Before installing clean and heat on a hot plate to approximately 100°C.
^ Temperature can be checked with temperature tester V.A.G 1558. Sliding gears
^ After installing, check axial clearance of 1st to 5th speed sliding gears. The gears should have a small amount of axial clearance and should rotate freely.
Clutch mechanism
^ Do not cant clutch pressure plate, loosen and tighten diagonally in small steps.
^ To reduce odor caused by a burned clutch, thoroughly clean the clutch bellhousing, the flywheel and the parts of the engine facing the transmission.