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View Full Version : Dual mass flywheel / rear main seal question



BimmerWill
06-23-2014, 03:52 AM
So I got the car up on jacks the other day to replace the differential bushings (Hell of a job by itself) and while I was taking the necessary parts loose in order to do so I noticed that the rear main seal appears to be leaving from what I can tell (oil coming out from around tranny bell housing) though not a substantial leak but still one im not particularly happy to live with.

I've decided to go ahead and replace the clutch and other necessary items while I do this but when I searched on ECStunings website all I could find for the "rear main seal" was a gasket when from what I understand there is a bearing that needs to be replaced. Am I missing something here?

For my second question, im going to go with a south bend clutch through ECS as well but I'm not sure if the flywheel should be replaced (car going on 225k at the moment) though I'm thinking it probably does. Im curious if anyone has any suggestions as to if I can determine this without removing the tranny. If it's not to too much of a rattle I was thinking about getting a single mass but from the prices I've seen it isn't really any cheaper to go that route.

In total im going to order
South bend clutch stage 1
Shifter rebuild kit
Driveshaft giubo (stress fractures all over it)
Rear main seal
Flywheel (depending on if it's needed which I'm fearing that it is)

If there's any insight you all can give as to what else I should order or in relation to my questions I would greatly appreciate it.

Sorry for the long post didn't want to blow up the feed with multiple questions.

Thanks fellas


sent from S4

brettbimmer
06-23-2014, 04:09 AM
I have never attached a rear main seal on the M54, but if your flywheel is original, replace it while you are there. My DD needs a new one as it often is difficult to get a smooth start in 1st gear. This has been true for a while now, and the original dual-mass flywheel has 265,000 on it.

Random question- any chance the oil is leaking from elsewhere on the engine, like a valve cover gasket? Would hate to see you tear into everything to find out it wasn't the source.

Sent from my pineapple under the sea.

BimmerWill
06-23-2014, 04:25 AM
It's not the valve cover gasket I replaced it maybe less than 40k ago. It's definitely coming from the bottom half of the motor best I can tell.

sent from S4

Hornung418
06-23-2014, 06:06 AM
Is it dripping from the drain on the bell housing? I have that leak. I will hopefully be replacing my Oil Pun for the Bimmerworld offering and will reseal the pan. Hopefully the majority of my oil loss will be relieved.

I would tighten down on your oil pan bolts and monitor your oil levels.

Sent from my GS3.

BimmerWill
06-23-2014, 06:30 AM
I don't believe it's coming from the oil pan as it does seem to be coming from where the transmission and motor mate not where the oil pan is. Granted I could be wrong and there is no real way to tell until I take the transmission out.

I guess I'll be ordering the flywheel. So much for saving some cash up this summer :/

sent from S4

Vas
06-23-2014, 06:55 AM
Could it be coming from the top of the transmission and leaking down? IIRC there is a seal up there somewhere.

Hornung418
06-23-2014, 10:54 AM
I don't believe it's coming from the oil pan as it does seem to be coming from where the transmission and motor mate not where the oil pan is. Granted I could be wrong and there is no real way to tell until I take the transmission out.

I guess I'll be ordering the flywheel. So much for saving some cash up this summer :/

sent from S4

IDK Will, you should definitely give those bolts a good torque value check. It could just be an issue with the pan gasket.

But don't freak out if it's a slight loss over your regular oil change interval. Its cheaper to deal with the oil loss than change the seal...

Sent from my GS3.

BimmerWill
06-23-2014, 01:37 PM
Well I was going to do the clutch and flywheel, shifter rebuild, and the seal while I had the time and the spare money. Granted I would hate to get all that apart to find out the leak is not coming from the seal but if it isn't I will have fixed something that's been in the back of my mind about the car for a long time.

Im just not exactly sure what it is I need to order.

Is it a gasket or a bearing that is needed to be replaced?

sent from S4

BimmerWill
07-02-2014, 02:29 PM
Took this a while back but figured id post it. Do you guys think the flywheel really isn't needed to be replaced? I honestly know nothing about these dual mass flywheels.

http://img.tapatalk.com/d/14/07/03/yjumymyt.jpg

Avetiso
07-02-2014, 02:35 PM
I would simply because I wouldn't want to take everything apart and not replace it. On the other hand, considering the mileage on the car, if it's still in decent shape, and it could last another 100k, you could just leave it and save the money considering the car has probably served most of its life.

Sent from my SM-G900T using Tapatalk

BimmerWill
07-02-2014, 02:40 PM
The only thing I'm concerned with is that some of the things I've read about the flywheels is that if you don't replace them with a new clutch due to buildup and wear on them they can mess up the new clutch in a rather short period of time and that would completely defeat the purpose of me doing it if its simply going to mess up the new clutch. I don't plan on getting rid of the vehicle even if I were to buy a new one. She's beginning to show just a tad bit of rust in some of the undercarriage but nothing to be alarmed about. Everything seems pretty solid and I feel like if something were to happen to the motor after next year it would give me the opportunity to do something really cool with it. I guess I'll see what things look like when I get in there.

Avetiso
07-02-2014, 02:42 PM
If you have plans to keep it for a long time, replace it, IMO. Others may disagree.

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az3579
07-03-2014, 07:13 PM
The only thing I'm concerned with is that some of the things I've read about the flywheels is that if you don't replace them with a new clutch due to buildup and wear on them they can mess up the new clutch in a rather short period of time and that would completely defeat the purpose of me doing it if its simply going to mess up the new clutch. I don't plan on getting rid of the vehicle even if I were to buy a new one. She's beginning to show just a tad bit of rust in some of the undercarriage but nothing to be alarmed about. Everything seems pretty solid and I feel like if something were to happen to the motor after next year it would give me the opportunity to do something really cool with it. I guess I'll see what things look like when I get in there.


To address this issue, my tech friend runs some kind of brush over the flywheel surface to get that "stuff" off. He has never had an issue doing that.



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