Terrible oil leak

[Tonyyy]

Hello,

I'm having a real fast oil leak coming from the back of the motor on my e30 318is. Ive searched, and I'm guessing it the rear main seal that's worn or bad. It's right under where the transmission meets the engine. I know my tranny mounts are shot as well, could that have aided the leak?
Also, how difficult is it to replace the rear main seal, or is it something I should take into a shop?

Any help or advice would be much appreciated!

Thanks,
-Tony.

[DesktopDave]

It's not difficult to replace the seal at all.  It is hard to take out the transmission & clutch though.  If you're going to do that I'd consider doing the clutch at the same time too.

How bad is the leak?  How often do you top it off?

Bad transmission mounts can wear out the guibo, output shaft seal or center support bearing after months of thrashing the car.  If you take it easy it's not that bad.  The cars are pretty well put together.

[Tonyyy]

I just replaced my CSB and Guibo a week or so ago, my tranny mounts were next on my list. But, this leak sprung and I'm pretty concerned now. The leak is pretty bad, I'm adding a quart every week or so.

Looking deeper into the engine bay, I noticed that one of the male torx bolts connecting the tranny to the motor appeared to be missing towards the top of the junction. Maybe it could have vibrated loose and fell out?

[DesktopDave]

Those bolts should be pretty tight, I wonder if the PO or mech got lazy on the lat clutch?  Yeah, it's a great idea to fix that.  Due to the seal's design it's unlikely, but you never know if it will totally fail.  At high RPM it'd drain your oil pretty quickly, by the time you see the pressure warning light it'd likely be too late.

It'll also create a hazard for other drivers, particularly motorcyclists.  I low-sided on some oil a while back in the middle of a tight curve...