O-Rings, Gaskets, Seals

O-rings, gaskets and seals must be replaced.
After removing gaskets, examine contact surface on housing/shaft for burr resulting from removal or for other signs of damage.
The open side of the seals point toward the fluid to be sealed in.
To install, thinly coat gaskets along outer circumference and on sealing lip with Automatic Transmission Fluid (ATF).
Coat o-rings with transmission fluid or Vaseline before inserting to prevent crushing rings during installation.
Always only use approved Automatic Transmission Fluid (ATF) or Vaseline. Other types of lubrication cause faults to occur in the transmission hydraulics.
When installing the new shaft seals, make sure the sealing lip does not run on the same point as the sealing lip of the old seal (use insertion depth tolerances).
Replace paper gaskets, thoroughly clean sealing surfaces and completely remove old seals.