Replace rear main seal while doing clutch?

[NickD]

I'm getting ready to do the clutch on my N55 6MT. I've read that the N55 doesn't really have issues with the rear main seal. There's 112k on the engine right now and I'm debating on passing on the rear main. I was wondering what other folks have experienced.

[cerealwars]

Looked into this a bit when I did my clutch last May on my n52 at ~130k. Bought all the tools and such to be prepared. Got all the way in there and it was bone dry, so I left it alone. Not worth worrying about IMO.

[tracer bullet]

I'd agree. If they were known to go out, it might be a different story. Those (unlike so many other potential BMW leak sources) seem to be OK.

Keep in mind there's a chance you'll take a good seal out, and put a bad one in / do it incorrectly / not prep the crank correctly and they won't work together, etc. and create a problem that didn't previously exist.

Good thinking on "while you are there", it does often apply. Not sure about this one though.

[kashikoi]

Yup left my RMS alone when replacing my clutch about couple months ago. It was bone dry. Input transmission seal also bone dry so left it alone. Shift shaft seal was leaking like a mofo so replaced that while I had the tranny out. It looked like my output shaft seal was also leaking but upon closer inspection it looked like it was just wetness from the shift shaft seal coming down. Couple months later my guess was correct; everything all nice and dry now. In fact having done the valve cover gasket, oil filter housing gasket, oil pan gasket, and oil level sensor gasket, not a single drip anywhere now. Is this even a bimmer anymore?

[NickD]

Thanks for the feedback. If it's dry and clean in there when I pull the trans I'll leave it alone. As far the input shaft seal, I think my input shaft bearing is shot so I'll likely be replacing the seal when I do that.

[ShocknAwe]

New one you put in could fail early ...

Let sleeping dogs lay.