O-Rings, Gaskets, Seals

O-rings, gaskets and seals must be replaced.
Seals are also called shaft seals.
After removing gaskets, examine contact surface on housing/shaft for burr resulting from removal or for other signs of damage.
Thoroughly clean housing joint surfaces before assembling.
Replace paper gaskets, thoroughly clean sealing surfaces and completely remove old seals.
Lightly coat the seals with ATF along outer circumference and along the sealing lip.
Coat the O-rings with transmission fluid or Vaseline before inserting them so they are not crushed during installation.
Do not use any other lubricants in the gear oil area. Otherwise there is a danger of malfunction of the transmission hydraulics.
The open side of the shaft seals point toward the fluid to be sealed in.
Press in new shaft seal, so that the sealing lip does not run on the same point as the sealing lip of the old shaft seal (use insertion depth tolerances).
Follow the rules for clean working conditions, refer to CLEAN WORKING CONDITIONS .