Rear main seal replacement?

[rabley]

Is anyone able to offer advice/ opinions on whether my rear main seal needs replacement? (T6 CAAC engine, 6 speed box, mileage 75k) And if I need to replace it, do I need to drop the sump and use the special tool T10134 or is there a work around? I have just dropped the box and removed the clutch and dual mass flywheel and found oil around the seal (see attached) but I can't work out whether the oil is coming from the bolt holes or from the seal. I included a picture of the back of the dual mass flywheel where it appears to have a fine oil misting. There doesn't appear to be any leakage at the 6 o'clock position directly below the seal so that's what's confusing me.

Reason for doing the clutch was because the slave cylinder bearing (CSC) started failing. The clutch was also getting juddery so I assumed brake fluid had got in the clutch. However, it now seems it may be oil and not brake fluid.

Any advice and shared experience appreciated.

Thanks

 

[catfood12]

I'd agree, there doesn't look like there's any oil around the seal. My 2017 CXEB DSG had oil leak fixed under warranty back in the day that was leaking through the bolts. It was quite a leak leaving a small pool when stopped each time. That was fixed with new bolts/sealer and has been fine ever since.

 

[Dellmassive]

This looks like engine oil?

If it is, then it shouldn't be outside the engine.

So it must be coming from somewhere.

 

[rabley]

Yes it's definitely engine oil. The bolt holes for the flywheel go through to the engine. So what you can see through the bolt hole is the inside of the engine. When the flywheel comes off, surplus oil leaks through the bolt hole and onto the seal area so you have no way of knowing whether the oil came from the seal or the bolt hole. Also, I now think that if the seal was leaking you wouldn't necessarily see oil at 6 o'clock position on the seal. Instead, the oil would track to the flywheel side and centrifuge outwards when the engine is running. Looking at the flywheel picture you can see fine radial oil marks. So I'm 99% sure there is an oil leak and I suspect it's from the bolt sealing. I think I have just caught it early. I have ordered the special RMS tool now for £30 and a new seal assembly off Autodoc for another £30 (VW wanted £174 for the seal!!!)

 

[rabley]

To finish off this thread for anyone interested in the future, I have attached some pictures of the rear main seal replacement which turned out to be quite a simple procedure. All that was needed was a new RMS (£27 from Autodoc) and RMS installation tool (£32 from eBay) and a crank pulley TDC locking tool (£9 on eBay). Remove auxiliary belt and pulley. Rotate crank to TDC and install locking tool. (Timing belt covers don't need to be removed.) Disconnect Hall Sensor (one screw). Remove 8 bolts from RMS and extract it using 3 M6 bolts. Clean and prep mating surfaces and put a small amount of silicon gasket sealant on sump sealing surface. (I didn't remove sump). Install new rear main seal using special tool and torque to achieve correct installation depth. 35Nm gave me exactly 0.5mm sub-flush to the ring so was perfect. Fit and re-torque RMS bolts (15Nm) and hall sensor (5Nm). Unlock crank and re-assemble auxiliary belt and pulley. Job done! Is was fairly easy.