John McM

Getting the pistons off requires removal of a circlip and then driving the wrist pin out. I got there eventually, but did it in the wrong order and took the cylinders off unnecessarily early. That meant protecting the rings while holding the piston and the socket and using the mallet.

I found out after the fact that the easiest way for a left hander is to start at cylinder 3. Rotate the engine until the piston is at TDC. Remove the cylinder far enough to get a good view of the wrist pin. Remove the right hand circlip. A strong pic is the best tool for that. Look for the hole closest to the end of the circlip, hook the end out and use needle nose pliers do gently pull the circlip out. Take a suitable socket (I used a 14mm) and place on the left hand of the wrist pin. Gently tap on the socket with a rubber mallet. The pin should start to move. Push it all the way until the pin falls out. Pull the piston and cylinder out together. You can leave them together until you need to look at them. Move to cylinder 2 and repeat then cylinder 1. Then move to cylinders 4,5 & 6. Place rubber bands on the rod ends to hold them. If you are right handed then move in the other direction. You want your dominant hand tapping the socket.

John McM

When the cylinders are all out, orient the engine with cylinders 1-3 face up. Remove the rubber bands and fit the chain and rod holders.

John McM

Remove the intermediate shaft cover, then all of the bolts holding the case halves together. There are a lot of them. Gently hit the case ears with a rubber mallet and the case should pop. If it doesn't, then check again that all of the bolts are undone. Lift the case half off and gaze at the oily bits that will cost you $$$ if you don't look after them.

John McM

Remove the crank shaft and undo the bolts for the oil pump then lift that and the intermediate shaft out.

John McM

You now have two case halves with just bearings attached. While the sight is impressive the first time, I now understand why mechanics avoid splitting the case. Apart from bearings there isn't much to go wrong in there and the uncertainty of a reseal could make splitting the case a poor risk / reward option

me964

great pics, thanks for sharing them !

"light refurb" ... as the title says

John McM

I enjoy posting and am glad it interests a few people out there.

As for 'light refurb' it's a case of under promising and over delivering

John McM

Now onto the reason for the disassembly, the leaking nose bearing.

As you probably know, all of the crankshaft bearings are solid and pressure fed with lubricating oil. The pressure is ~ 5 bar (72 psi) at full throttle.

The rear main seal and nose bearing are at opposite ends of the crankshaft and are sealed differently. In my car, the leaking bearing area is the nose bearing.

The bearing is fed oil at its side. This lubricates the surface of the bearing in contact with the crankshaft.

Any oil that runs to the end of the crankshaft is caught by a seal and runs back to the case inside via two holes. Any oil that runs outside the bearing inside the case is caught by the o-ring and fed back into the case via the relief channel.

The various methods of stopping a leak around the outside of the bearing look to improve the sealing. As I have a leak when there is no sealant I'm not leaving it without anything. The question is which option to take? I'm leaning towards Threebond 1211 on the outer bearing face and Dow 111 on the o ring

tdiquattro

I am just about to fit the Tom Amon ring today, so understand this. I suppose you can only put sealant on the thin shoulder after the oring as the oil would be passing on its way out?

Otherwise dont you risk blocking the feed hole?

John McM

Your experience may vary but the Tom Amon collar didn't work for me. The JB weld didn't adhere to the case for long then it became a nightmare to remove. I would use an RTV type sealant instead of JB Weld and I would keep the grub screws heads clear and easy to access.

The hole for the oil feed would be very difficult to block with sealant. The suggestion elsewhere is a translucent film. I think I will use 111 on the o-ring and 1211 on the outer edge in touch with the case.

911Jetta

But now you can say, "I split the case"! That's a whole 'nother level!
Keep it up, lots of us lurking and enjoying the show (with clean hands).

C4inLA

+1 what he said... Thanks for sharing great pics and observations during the deep dive... Been Subscribed...

Meatball964

Not sure if I agree re: splitting the case being a "poor risk/reward option". I suppose car mileage would factor into it. I debated whether to split or not, but @ 192k I felt replacing the rod bearings, timing chain & cleaning out the case (oil galleys) the reward out weighed the risks. I'll let you know if I still feel that way once I start next week lol.
As Steve W. said, you don't want a "repeat performance".

John McM

Mileage would be a factor and 192,000 miles is getting up there. As long as the fasteners are all undone the split itself is uneventful. Getting it back together will be more fun. There are a lot of fasteners in a limited time and in a specific sequence.

Meatball964

Why a "limited time" ? Are you referring to sealant drying time ?