Replacing front crank seal...question and tip

[1999750il]

Hi all,
After removing the old seal with the proper tool and cleaning off the area...I am getting ready to replace with a new BMW seal for my 750il. Many have suggested lubricating both the outer and inner seal with motor oil while others claim the outer edge already has a red lubricant film from the factory and should be installed dry...while others say to put a film of rtv gasket.... what is the best way to prevent future leaks?
if both should get lubricated should I use motor oil or some sort of grease...I should be able to start the engine by next week

tip or others ...buy the bmw seal. I had purchased the timken part and both the inner and outer seals were narrower than the bmw part....which would give less of a sealing area
thanks for the advice

[motion]

As always do as you feel is best. Use a OEM seal, Inspect the hub for fretting and polish thoroughly. I prefer a thin film of grease on the inside lip, a little between the two lips and either oil or grease on the hub. Take care to install the seal squarely. Is the lower case on or off the engine?

[1999750il]

Hi Motion,

I am definitely using the BMW OEM seal...it just looks like it would prevent leaks better than the Timken. As for the hub...on my 750 the hub of the balancer does not ride on the deal. Its the snout of the crankshaft itself that rides on the inner rubber seal. The crank pulley hub simply slips on. The lower case is still on..I simply used the proper tool to properly remove the old seal and will use another to properly seat the new seal. I think I will oil the outer rim of the new seal...even though it seems to have a red coating on it already and apply some grease on the rubber lip seal. What kind of grease is recommended for this...the white lithium grease or the typically bearing grease?

Thanks for all the pointers

[motion]

I'm not that familiar with the 750's, but generally the rotating (static) part is readily changeable. Is your hub keyed, if so be careful with the seal while passing over that area. In either case insure that the seal sealing area is super clean, I polish mine with crocus cloth. If there's fretting you may need to decide to move the seal further in or out. I usually use a good bearing grease.

[CPHES]

Once you have it apart - it sounds like you do. Press the new one in, I used a little motor oil on the inner seal lip.