Crank Oil Slinger

Post by: **AlfaLofa** » Tue Nov 26, 2013 3:55 pm

I've got a pair of new front and rear crank oil seals.

The rear seal is a good tight fit on the crank whereas the front seal (in the timing case cover) is much larger than the crank diameter where it passes through the cover.

It got me thinking - what's the point of this seal, or more precisely how does it work.

My manuals, parts lists, books etc. don't really show how the front seal works.

I presume that the slinger locates onto the crank via the woodruff key and then the seal in the front cover pushes against the slinger to prevent it migrating up and down the shaft.

Is this correct? Is the slinger simply held in position by the seal - or am I missing something

I did a search and found this concerning the slinger:

"Anyway, it does not have any washer between itself and the sprocket and the dished profile faces away from the sprocket and effectively covers the oil seal, presumably to reduce the chance of leakage".

Post by: **types26/36** » Tue Nov 26, 2013 4:13 pm

The front seal lip runs on the crank pully and seals against it, the slinger which is on the crank is trapped against the crank sprocket and held tight when the pulley bolt is tightened.