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Rear Engine oil seal leaking badly

3788 Views 3 Replies 2 Participants Last post by  markakeller
My Jetta with an ALH engine was in the shop getting the 5 speed, clutch and rear engine oil seal replaced. When I received the car back within a few days engine oil was leaking out of the rear seal badly (enough to completely wet and create a puddle in the bottom cover and of course large puddles in the driveway). I took it back, they pulled everything back out and this time even pulled the oil pan and resealed everything along with a new seal from VW. It leaks just as badly again. I've read the article on this site about installation of the seal and it seems straight forward. I also see removal of the oil pan is not necessary. I also know they have not used any lubricant on the crankshaft seal and they let it sit before running it. They also kept the plastic guide in place as they slid the seal on. In reviewing all of this with the shop it seems it was all done correctly. I can't imagine what was missed to cause such a bad leak or what special trick there is to get the seal installed correctly. Should a sealent be placed on the flange seal all the way around? It seems very straight forward and not tricky at all. This is reputable local general shop.
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Removing the oil pan isn't "necessary" but it's the correct way to do it according to the factory.

Some have used lube on the seal and it didn't cause leaks so that's not the problem. If the shop went to replace everything a second time I'm sure they checked that it's not the valve cover or turbo oil lines.

It's very straight forward so I don't know what could be going wrong. The only trick is to use the plastic guide to slide it on so that the seal doesn't get folded over. And if you use the plastic guide it's pretty much impossible to damage the lip. Perhaps they are over tightening and cracking the flange? The obvious thing to check is for cracks in the oil pan or flange or that the correct seal is being used.
Possible Solution

Took the car to shop #2 and they checked that the back side of the seal is properly mated to the block, which it was. Then they found that the oil was likely leaking around the flywheel to crankshaft bolts. They sealed the threads on these bolts. I hope this is the solution. I have read no where about sealing these bolts as a potential leak source. I should note that at the beginning of the oil leak problem the stock dual mass flywheel was replaced with a solid flywheel and clutch conversion kit from Valeo. I'll follow back up if this in fact the solution to the problem.
After 200 miles of driving this appears to have stopped the oil leak from the rear main seal. No oil leaking at all.
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