REAR MAIN SEAL LIPS

[swolsky]

Hey Everyone,

I have this rear main seal that is leaking. We have noticed on the OEM sample that there is a fat lip at the end that seals on the crank shaft and we believe this is what prevents the oil leaking past.

The production seal we recieved does NOT have this lip and it looks like the seal was cut at an angle making a "thread" like feature that helps work the oil through the sealing lip and spitting it back into the bellhousing as it started leaking very quickly.

Please see the photos below depicting what we are noticing. Does anyone have an experience with Radial seals that could educate me on the design.

 

[mfgenggear]

OP
Contact the OEM or an after market supplier
To get the correct seal.

 

[dtimberlake]

" the seal was cut at an angle making a "thread" like feature that helps work the oil through the sealing lip and spitting it back into the bellhousing "

What direction does the crankshaft rotate relative to the seal "thread" ?

Is country of origin molded on the seal? Does that match what the box/package said?

Was the engine leaking oil before the seal replacement ?
Clogged PCV etc can cause excessive crankcase pressure that will overcome 'most any seal.

 

[mfgenggear]

Generally seals leak because of bearing wear causing out balance. Or improper instalation of the seal. As stated excessive worn rings will Cause internal crank pressure.

 

[TugboatEng]

The wide rim at the end is likely where the seal is worn.

 

[3DDave]

I do have a vague memory of seals made with a spiral groove intended to act as a weak pump to push oil back against exiting the device, but that would only work if the spiral had the correct handedness; if it didn't it would tend to force oil out, something not desirable.

The original looks to have some simple grooves to maintain an oil reservoir to keep the lip seal lubricated.