To lube or not to lube

[indy4x]

Seem to have differing opinions

Currently have my Jeep GC ZJ gearbox out to replace the clutch and rear oil seal and o rings

New seal and o rings are Viton

Workshop manual doesn't specifically say to use of lube on the seal or o rings but I usually do

Apparently some seals do not need lube before installation

Opinions please

 

[m_c]

Crank seal depends on the type of seal.
If it's the type that's multiple layers of material (I can't remember the correct name!) and has to be installed with an installer to stretch the seal over the crank, then it should go on dry, as they're designed so some of the material is transferred to the shaft. If you lubricate them, then they won't seal as well, and are likely to weep.

Standard single/double lip seals, a little bit oil (or grease if it's a low speed shaft) in the seal itself, and some on the shaft.

 

[indy4x]

@m_c

Yeah, it's a standard viton double lipped seal

Think the ones with the installer are Teflon maybe?

The 2.5TD VM engine fitted in the Jeep (and others), the seal is installed in the rear of the engine but the seal inner lips run on the flywheel

 

[Cobbler]

Some of the lip seals are pre-lubed, they have grease in between the inner & outer lips. If not I always greased or oiled them as if not it could wear or burn the sealing edges off.