RMS (rear main seal) -- Question & Advice...

Kevin The Clean 1 · 28th January 2013, 12:12

My RMS has been leaking ever since I bought my M5. I'm finally at the point where I'm deciding to take care of it. While I drop the exhaust & transmission I will be putting in a brand new CNS racing clutch as well. My question is (since I have only seen people work on their M5 rear main seals in videos & in pictures) I'm not sure exactly what it looks like & what the actual part numbers are. THANK YOU in advance for your time & help...

RealOEM.com * BMW E39 M5 Engine Block Mounting Parts

Is it #7 & #8 that I want to replace in this diagram above ^^^... ?

RealOEM.com * BMW E39 M5 LOWER TIMING CASE

Or is it #6 & #7 in this "other" diagram above ^^^... ?

.

M5 Sydney · 28th January 2013, 12:33

It's 6, 7 & 8 in the first link - if you want to change the carrier too. You can change only the actual seal (7) although some people recommend installing the seal pre fitted in the carrier. Others may chime in with advice on this...

The second link is the front seal around the harmonic balancer.

Nick

Jahdave · 29th January 2013, 01:48

When are you doing this? Do you need help, or are you having a shop perform this function for you?

hairball · 29th January 2013, 02:35

Just buy this part number (#6 on your first link) and you will have everything you need for the rear main seal job. Plus, the seal comes already installed. All you have to do is tighten it up. Comes with #11 too (see your first link) which also leak oil.

John

ME_264 · 29th January 2013, 03:13

I've done both the 540i and the M5 RMS. Never bought the carrier as I've got a press and made a drift to press it into the carrier. But, all the other parts are a must have.

My advice on doing it is to a) watch the bolts from the oil pan that hold the carrier down (eg, don't force the carrier off without removing all the bolts!), b) clean all surfaces.

c) You may have scoring on the crank, it's probably fine even if it's noticeable (I've put 60K on one that looked terrible and still no new leakage).

d) When installing the carrier/seal besure to lube up both the crank and the seal. Work hard to press evenly and have the lip seal go over the end of the crank all at once. You can't twist it due to the oil pan but as long as it goes on uniformly it will be fine.

YMMV and Good Luck!

Kevin The Clean 1 · 29th January 2013, 07:36

Quote:

Originally Posted by Jahdave

When are you doing this? Do you need help, or are you having a shop perform this function for you?

IN the next few weeks but there is no way I would be doing this myself. I've done 95% of the work on my M5 but dropping the tranny & putting in a new clutch is way too much work for me. I don't want to mess up the install of my CNS Racing clutch & new RMS. I'm not sure who I will have install it yet but I'm researching right now who I want to have the work done by...

Quote:

Originally Posted by hairball

Just buy this part number (#6 on your first link) and you will have everything you need for the rear main seal job. Plus, the seal comes already installed. All you have to do is tighten it up. Comes with #11 too (see your first link) which also leak oil.

John

That is the part I will order then (#6) which seams to come as a kit... Thanks so much.

To everyone else, thanks for the help as well. I really do appreciate it...

.

mgdmb · 29th January 2013, 07:45

Quote:

Originally Posted by Kevin The Clean 1

IN the next few weeks but there is no way I would be doing this myself. I've done 95% of the work on my M5 but dropping the tranny & putting in a new clutch is way too much work for me. I don't want to mess up the install of my CNS Racing clutch & new RMS. I'm not sure who I will have install it yet but I'm researching right now who I want to have the work done by...

Throwing a recommendation your way for BRRacing in Los Gatos. They did my CNS clutch / RMS last year... can't recall the labor hours off-hand (PM me or swing by if you want me to find the invoice...), but it's been trouble-free for 17K miles.

M
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Standard Disclaimer: Not affiliated with the shop in any way...

Kevin The Clean 1 · 29th January 2013, 07:58

Quote:

Originally Posted by mgdmb

Throwing a recommendation your way for BRRacing in Los Gatos. They did my CNS clutch / RMS last year... can't recall the labor hours off-hand (PM me or swing by if you want me to find the invoice...), but it's been trouble-free for 17K miles.

M
--
Standard Disclaimer: Not affiliated with the shop in any way...

Thanks man & I'm glad you saw this. I've been really busy but I've been meaning to bring my car by & say hi. When I get some free time I will swing by to ask you about it. I would love to hear your thoughts on how you like the clutch thus far. I would also love to hear how loud the single mass unit is. I'm assuming that's the one you got since it was about a year ago. But your M5 makes much more sound then mine does (and a very good sound too) so I'm sure it's not easy to hear the clutch chatter that people say the single mass clutches are know for...

In any case, I'll talk to you soon. Just have some last minute odds & ends to get sorted out.

mgdmb · 29th January 2013, 08:04

I actually have the dual-mass, so I can't comment on chatter or lack thereof. But I will say I love the hook-up of the CNS clutch / flywheel.

PM me when you want to swing by.

timmay77 · 29th January 2013, 10:39

Quote:

Originally Posted by hairball

Just buy this part number (#6 on your first link) and you will have everything you need for the rear main seal job. Plus, the seal comes already installed. All you have to do is tighten it up. Comes with #11 too (see your first link) which also leak oil.

John

This.....

Make sure you put a very thin layer of RTV on the bottom of the flange.

If you are feeling sparky, I would replace all 4 CPS's while you have the transmission out. They are a complete PITA to get to from the top side, but UBER easy to get to with the transmission out.