G35 Sedan V35 2003-06 Discussion about the 1st Generation V35 G35 Sedan

rear main seal leak

Thread Tools
 
Search this Thread
 
Rate Thread
 
Old Oct 15, 2015 | 11:03 AM
  #1  
rb25s14's Avatar
Thread Starter
|
Registered User
iTrader: (2)
Joined: May 2006
Posts: 43
Likes: 1
rear main seal leak

My g35 seems to be leaking from the rms. The oil cooler seal seems fine.
What's the "easiest" way to fix it? Can it be changed by just removing the transmission or does the upper pan need to come off too? Is the actual rms usually the problem or is it the half moon seal?
Would I be better off just pulling the entire engine out? I have access to an engine hoist but no lift and all work would be done by myself so I'm looking for the easiest way.
Thanks.
 
Reply
Old Oct 15, 2015 | 01:32 PM
  #2  
LoSt180's Avatar
Premier Member
iTrader: (11)
Joined: Mar 2011
Posts: 2,796
Likes: 468
From: Maryland
Premier Member

You can just drop the transmission and remove the flywheel. The seal bolts up to the back of the engine. Looking at pictures online, the seal is part of a retainer, pretty simple IMO.

https://www.z1motorsports.com/piston...de-p-4137.html
https://conceptzperformance.com/Cart...on.php?II=3040

Only other thing I can think of is to possibly replace your clutch, flywheel and throwout bearing while you're in there so that you only have to drop the trans once. It's optional of course. Might even order everything just in case and return it if clutch is fine.
 
Reply
Old Oct 15, 2015 | 01:47 PM
  #3  
rb25s14's Avatar
Thread Starter
|
Registered User
iTrader: (2)
Joined: May 2006
Posts: 43
Likes: 1
The problem is that half moon seal. Can the rms&retainer + half moon be installed without dropping the upper oil pan?

Thanks
 
Reply
Old Oct 15, 2015 | 02:18 PM
  #4  
LoSt180's Avatar
Premier Member
iTrader: (11)
Joined: Mar 2011
Posts: 2,796
Likes: 468
From: Maryland
Premier Member

This "half moon" thing are you referring to the upper oil pan gasket?

Item #1 in this pic?


I don't see how that can be replaced without dropping the upper pan.
 
Reply
Old Oct 15, 2015 | 02:33 PM
  #5  
rb25s14's Avatar
Thread Starter
|
Registered User
iTrader: (2)
Joined: May 2006
Posts: 43
Likes: 1
Yeah the problem is that seal sits inside a groove on the bottom of the rms. It looks like if you remove the rms that seal will also come out.
Looks like fun.
 
Reply
Old Oct 15, 2015 | 08:53 PM
  #6  
saywat?'s Avatar
Registered User
iTrader: (5)
Joined: Apr 2009
Posts: 8,439
Likes: 484
the easiest way to do this is to take it to a shop lol jk i did. i recently had this done at a friends shop. idk the details but they were able to do the rear half moon and rms without removing the entire mid pan jus removed the trans and threw a new clutch in there for me. but i also had a small leak at the front half moon so half pan had to come out as well as most of front suspension.
 
Reply
Old Oct 21, 2015 | 11:48 AM
  #7  
Wrathernaut's Avatar
Gentle Manne of Leisure
15 Year Member
Liked
Community Favorite
iTrader: (5)
Joined: Nov 2008
Posts: 7,994
Likes: 1,050
From: Pennsylvania
Premier Member

I've got a small one from mine. I just decided it wasn't worth the effort to fix it until I need to change the clutch again. I can deal with a few drips a day.
 
Reply
Old Oct 24, 2015 | 02:04 AM
  #8  
rb25s14's Avatar
Thread Starter
|
Registered User
iTrader: (2)
Joined: May 2006
Posts: 43
Likes: 1
Just finished mine by myself. Was a royal PITA and yes the upper pan needs to come off. It just needs to come off just enough so you clean the surfaces and apply rtv & gaskets .
And I found while it was leaking a little the main cause is my left bank valve cover gasket that I just changed a few months ago. I'm not sure why it's leaking again damn it. :0
 
Reply
Old Oct 27, 2015 | 02:15 PM
  #9  
saywat?'s Avatar
Registered User
iTrader: (5)
Joined: Apr 2009
Posts: 8,439
Likes: 484
wat do u mean the valve cover gasket was the main cause?
 
Reply
Old Oct 28, 2015 | 07:23 AM
  #10  
rb25s14's Avatar
Thread Starter
|
Registered User
iTrader: (2)
Joined: May 2006
Posts: 43
Likes: 1
The valve cover is leaking and oil is running down the back of the head but it's very difficult to see and it looks like only the rms was leaking. It's very hard to see back there and I think the cam shafts sensor was leaking too.
 
Reply
Old Oct 28, 2015 | 08:36 AM
  #11  
yosip1115's Avatar
Registered User
iTrader: (2)
Joined: Jun 2011
Posts: 1,089
Likes: 75
From: CT
Seems like you are asking for trouble if you try to seal up the RMS without completely dropping the upper pan. You guys said you need to drop it just enough but that means the RTV seal would be compromised significantly. Wouldn't the only proper way be to drop it clean it and apply a new bead? I read a bunch of horror stories so I decided to not replace my RMS for good measure when putting the new engine in. Others say you can get away without dropping the upper pan but you have to use way more RTV than the FSM recommends or it will leak again.

OP nice job, that is a lot of work but I hope it does not come back to bite you. You should check your PCV system, usually excessive crank case pressure will cause the seals to blow out. If you are still tracking down oil leaks try what I do... Use brake cleaner to clean off the engine from the top down with it idling. The oil will come back immediately on the spots that it is seeping through.
 
Reply
Old Oct 28, 2015 | 11:15 AM
  #12  
rb25s14's Avatar
Thread Starter
|
Registered User
iTrader: (2)
Joined: May 2006
Posts: 43
Likes: 1
Originally Posted by yosip1115
Seems like you are asking for trouble if you try to seal up the RMS without completely dropping the upper pan. You guys said you need to drop it just enough but that means the RTV seal would be compromised significantly. Wouldn't the only proper way be to drop it clean it and apply a new bead? I read a bunch of horror stories so I decided to not replace my RMS for good measure when putting the new engine in. Others say you can get away without dropping the upper pan but you have to use way more RTV than the FSM recommends or it will leak again.

OP nice job, that is a lot of work but I hope it does not come back to bite you. You should check your PCV system, usually excessive crank case pressure will cause the seals to blow out. If you are still tracking down oil leaks try what I do... Use brake cleaner to clean off the engine from the top down with it idling. The oil will come back immediately on the spots that it is seeping through.
I actually had the pan fully off but with just 3" of space between the block and the upper oil pan. It was enough to clean the surfaces, reapply rtv on both the block and oil pan and make sure the two o-rings were set in place . I spent a good 20 minutes cleaning it so I think it's good and as of this morning I haven't seen any leaks from the upper oil pan.
I wish I could have pulled it out completely but the cross member was refusing to drop down fully and at that point I was to tired too fight it anymore...
I also just installed an open catch can- I think I may have finally fixed my oil consumption problem after 9 1/2 years.
 
Reply
Old Oct 28, 2015 | 05:34 PM
  #13  
saywat?'s Avatar
Registered User
iTrader: (5)
Joined: Apr 2009
Posts: 8,439
Likes: 484
Did u do the job on Ur back under the car? If so Ur nuts and I give u hella props for that
 
Reply
Old Oct 28, 2015 | 06:24 PM
  #14  
rb25s14's Avatar
Thread Starter
|
Registered User
iTrader: (2)
Joined: May 2006
Posts: 43
Likes: 1
Originally Posted by saywat?
Did u do the job on Ur back under the car? If so Ur nuts and I give u hella props for that
Yup it wasn't that too bad on my back, I have enough experience with swaps. It's been almost a week since I finished it and my back is not hurting anymore so that's a good sign lol. Putting the transmission back in wasn't that bad too, I just used two jacks to lift in place.
 
Reply
Old Nov 8, 2015 | 05:07 PM
  #15  
rb25s14's Avatar
Thread Starter
|
Registered User
iTrader: (2)
Joined: May 2006
Posts: 43
Likes: 1
Well it's been about 2 1/2 weeks since I finished and not a drop of oil anywhere. I think the pcv bypass has a lot to do with that. Since then I've done the compression rods, ball joints and replaced a sticking rear caliper.
The G is no longer my daily driver but I'm impressed how well it drives for a car with 197k miles on it.
I'm just glad I can finally paint my garage floor
 
Reply


You have already rated this thread Rating: Thread Rating: 0 votes,  average.


All times are GMT -4. The time now is 08:49 AM.