Rear Main Seal

My girfriend’s 2000 Elantra with 175,000 m leaks oil from it’s rear main seal, which was replaced once before. Her mechanic has told her that it’s not worth replacing again, because the groove it fits in has widened and can never be sealed completely. Does this make sense?

It’s time for a second opinion. I don’t see any reason for “widening of the groove”.

Find a different mechanic, and get a second opinion.
Also, check with a Hyundai dealer, as they might have a redesigned rear main seal that is either wider, or installs deeper, to take care of this issue.

Porsche has several RMS variants for their liquid cooled engines, for just this reason.
Some are wider, some are installed deeper, others are both.

BC.

I have seen a pair of rubber boots hanging upside down in a pickup between the cab and the bed cut such a big groove in the driveshaft, it had to be replaced. So yeah the groove on a Hyundai crank, or for that matter any crank can get quite large to where it wont seal there. I don’t believe I have ever seen a repair sleeve for cranks. Don’t know why, it seems like there are sleeves for just about everything else. Maybe they have a seal that will actually put the lip on a new surface of the crank.

Apparently the mechanic has never heard of a Speedi-Sleeve. These are made for the express purpose of helping to prevent oil leaks in situations like this.

http://www.vsm.skf.com/en-US/HeavyDuty/KitsAndTools/SpeediSleeve.aspx

We had a similar problem with a Nissan some time back. Our mechanic, who builds dragsters as well, machined a new seal and for $550 the car does not leak any oil. Normal dealer shops as well as auto chains have no idea or interest in doing something like that.

The only reason to check with the dealer is to se if a better seal is now available.