Rear Main Seal

[B5AudiGuy]

I am in the process of replacing my clutch and after reading on here, I saw that it was probably a good idea to replace the rear main seal. My A4 has roughly 95k miles and figured, it wouldn't hurt. I noticed on ECStuning, that there is a significant jump in price, between the Genuine VW/Audi vs. the SABO and Elring. Is there really that big of a difference between the parts to justify that large of a price gap? Is the Genuine VW/Audi part better? Worse? Would it hurt to go with one of the other brands? Any insight is much appreciated.

Cheers,
Aaron R

[foley803]

I am wondering the same thing, I've ordered all my parts besides this because I couldn't decide.

[Audiguy1234]

I have the victor reinz and have no leaks. I have heard Elrings are good too.

[MikTip]

Victor reinz and or elring makem for Audi....the OOOO rings on a part drive up the price.

[foley803]

Great! I had never heard of Sabo or Elring, but if Elring is an OE supplier that's good as gold. I just didn't want to skimp on such a pain in the ass part.

[DiertyEuroSpec]

I was thinking the same thing but when I took the clutch off it wasn't leaking in the slightest!!! I guess it's like the cam seals when doing the timing belt if they're leaking get em done!! If not say thanks and keep on Oh btw I have 130k on the clock and on third clutch. Just replaced the Southbend SS OFE with the ECS RA4 kit. I am loving it so far too!

[MikTip]

The rear main seal is like a double edged sword....always good to replace while the flywheels off.

Better to do so by choice and not be forced to do so!

[Elliott]

It's one of those items that might be better to leave alone unless it's leaking IMO. You have to get it on perfectly straight and won't be certain it's installed correctly until you get it all back together and heat cycled a few times. I learned the hard way.

[MikTip]

The secret to the rear main seal is lube its internal surface which rides on fhe crankshaft with the same synthetic
oil you run in the engine. Then use the plastic tool which is suppose to come with the seal to install it.
No fear the rear main seal!

[MikTip]

The secret to the rear main seal is lube its internal surface which rides on fhe crankshaft with the same synthetic
oil you run in the engine. Then use the plastic tool which is suppose to come with the seal to install it.
No fear the rear main seal!

[Casius]

I'd leave it alone unless there's something wrong. Even if it were to start leaking, barring some epic fail it's not like all of a sudden you're going to be gushing oil by the gallon out of that thing. If it starts to leak a bit you probably have lots of time before actually needing to replace it.

[B5AudiGuy]

Thanks for all of the input. I am going to opt out of it for now. I was finally able to speak with my mechanic, and he advised me that its very rare that it does leak and it all depends on who last serviced/touched the part. He also told me, that it looks fine and noticed zero signs of dripping/leaking.

Cheers,
Aaron R

[Charles.waite]

Just noticed oil seeping out from the bell housing today when re-bleeding my clutch. Petty sure its my rear main seal but not positive. Can anyone advise yea or nay? There was oil seeping out of the holes on he bottom of the bell housing. Could very well be why my clutch has fairly suddenly given up the ghost on me.

[diagnosticator]

This is one main reason why maintaining the functional integrity of the crankcase ventilation system is so important. As designed, and when functioning correctly, the crankcase ventilation system maintains a negative pressure of about -3 to -5 inches water column in the crankcase. As long as the negative pressure exists during the average time for operating hours, it is almost impossible for seals to leak, since the outside air pressure is trying to get into the crankcase and prevents oil from being able to get out. The seal lip is also designed to cause the oil film in the seal to wipe toward the inside, also helping prevent the seal from seeping. If the crankcase pressure/ventilation function is compromised, and or the seal is completely worn out will the seal start to leak. The crankshaft seals used these days should last the life of the engine.

[walky_talky20]

Charles, it can also be your transmission input shaft seal. My brother had that start leaking on his his A4 at around 130k. Clutch was slipping like crazy...which sucked because he had *just* replaced the clutch and everything looked fine. When he took it apart the input shaft seal was leaking a bit and the rear main was even leaking just slightly. He was not a happy camper having to do the job twice.

[coowhip]

I have a rear seal I didn't use. Ordered it from MJM and I believe its victor reinz. Let me know if anyone needs its. I also have a pilot bearing. Mine wasn't leaking so they didn't replace it.

[A4orce84]

Bumping this thread back up. Getting ready to do my clutch in a month or 2, wanted to get some fresh input.

Thanks,
Asif

[SJorge3442]

Bumping this thread back up. Getting ready to do my clutch in a month or 2, wanted to get some fresh input.

Thanks,
Asif

Some change it out, some dont. I didnt. Then again, I was pinched for cash and time so I couldnt be waiting around for a rear main seal to show up. Looking back, I wish I swapped it for piece of mind. oh well. Hopefully I wont be the one with the car when it goes.

[redline380]

I wouldn't. Better not to do it because you could fail at installing it like I did. In these pictures, the dust seal is ripped off. Most of it came out of the hole in the bell housing. Look close, you'll see the error and the SOB leaked from day 1.

[DiertyEuroSpec]

I wouldn't. Better not to do it because you could fail at installing it

Very very true when working on these finicky biachtes!!

[Charles.waite]

I would get it.

I replaced mine when I did my clutch. I had reason to believe it had failed and when I pulled the flywheel, it has definitely failed. Its something like $25 online, I just ordered it up as I wanted to be prepared and I didn't want my car to be down even longer than it was going to be. I'm glad I did. And frankly its really not that hard to install. Just leave the install flange on, line it up, and slide it off the plastic install flange and onto the rear crank flange. Just be careful, and exacting with lining it up and don't force it.

Either way, I'd rather spend $25 extra and not get stuck halfway through the job because of a failed seal. If you get that far and notice its failed, and ignore it and continue reassembly, you're an idiot....

[MikTip]

IMO, The rear main seal is like a double edged sword....

Always good to replace while the flywheels off.

Better to do so by choice and not be forced to do so!

[CyberPMG]

IMO, The rear main seal is like a double edged sword....

Always good to replace while the flywheels off.

Better to do so by choice and not be forced to do so!

^^This. Also, since A4orce84 had also performed a Seafoam treatment to clean out the engine, it's likely the chemicals have weakened the seal and can lead to leaks. Since it's more accessible with the flywheel off, this would be the perfect opportunity to get it done. If you're hesitant on doing this yourself, then take it to a shop that can get it done for you and know it's done right. Money well spent.

[redline380]

If you are going to do it yourself, I highly recommend taking a 90 degree or curvy pick and lifting the dust seal up enough to ensure the lip has seated properly. my photos above are a perfect example of the lip not seating properly. the lip needs to be seated facing in all the way around.

[MikTip]

There are types of main seals out there...

The Old style, regular seal and the new PTFE version...

I prefer the older version.