Trying to install passenger side differential/axle oil seal on 2008 TL Base. Not sure how deep I should push the seal in. Does this photo show the correct depth, with the inner lip sticking out and outer lip flush with the differential case?

Should I put a thin layer of silicone paste on the surface of the seal (outside differential case of course) to protect the rubber seal from oxidation or premature aging?

 

^
The Helms states it should be 'flush to the transmission housing'. Refer to the attachment below.

 

Thank you for sharing the doc, Zeta.

It would be nice if Helms shows a drawing to clarify its instructions. After some trials and errors, I noticed the flat mating surface of the seal is of 5mm wide and the housing of 7mm. So there's some margin of tolerance. I think as long as the seal's flat surface goes in completely and rests within the 7mm housing surface, it should be acceptable. My photo showed about the correct depth when the seal's flat surface just cleared the edge of the housing surface.

 

This is why I take pictures before the seal is removed.