Blogs Car Info Our Show Deals Mechanics Files Vehicle Donation

2001 Nissan Pathfinder rear main seal

I have a 2001 Nissan Pathfinder with about 203,000 miles on it. Car is clean, well maintained and runs great. Over the past year or so it developed a rear main seal leak. It’s just a few drops every day. Dealer wants $1700, independent shop wants $1250, another shop says don’t bother, just add oil when it gets a little low…you can’t really fix that leak by putting a new seal on components that are 15 years old with over 200,000 miles on them. Looking for wise, sage advice whether to fix or not. I’d like to keep the car another 100,000 miles is possible. Thanks.

Spending large dollars to fix this leak will most likely cause other leaks to show up. You could go to Autozone or something like it and purchase a stop leak additive and it might help.
The shop that said don’t bother should move to the top of your repair list.

If it’s just a few drops and you check your oil level often…I would forget about it. Just put cardboard under the vehicle when it’s parked and change it out every so often.

$1200 will buy a whole lot of oil.

Make mine another vote to forgetaboutit except to monitor your oil level.

Engines don’t die because they drip a bit of oil. They die because people allow the level to get too low. The lubrication system works by the oil pump drawing oil up from a “pickup tube” (straw) the end of which is immersed in the pool of oil in your oil pan. As long as the end of the straw is immersed, the lubrication system protects the engine properly. It doesn’t even know the seal is weeping. It’s when the oil level drops below the straw that the engine seizes from lack of oil.

If it were in the front of the engine it might jeopardize the timing belt (if your engine has one), but it shouldn’t cause any other problems at the rear of the engine.

Oil leaks are annoying, make the driveway spotted with oil and slippery to walk on when wet. And if you go to visit someone and forget and park in their driveway, you’ll make their driveway spotted with oil too. So I’d want to fix that leak myself. I think $1250 is reasonable. They’ll have to remove the transmission, so if there’s any transmission servicing due, make sure that happens. If you have a manual transmission, now would be a good time for a new clutch install too. There’s a seal on the transmission input shaft that should probably be replaced too. And there’s a bearing/bushing gadget in the center of the flywheel that probably should be replaced, or at least taken a good look at.

I don’t agree w/the advice you got that the leak can’t be stopped with a new seal. A new seal will almost certainly stop the leak. Part of the job of replacing the seal is to clean the surfaces thoroughly, and that’s about all that is needed to guarantee a leak free job. This presumes you have no loud knocking noises coming from the crankshaft.

There’s a very slight chance – admittedly this probably won’t work – but there’s a hair’s width of a chance you can fix this for about $5. New PCV valve. A plugged PCV valve can cause the main crankcase seals to leak. For $5, worth a shot probably.

Start using a high mileage oil such as Valvoline Max Life.

These oils have additives that condition seals to stop leaks.

It costs a little more than conventional oil. But then, you don’t change the oil every day.


There are also sleeves made to install over damaged crankshafts to give new seals a smooth sealing surface . Redi sleeve , Speedi sleeve , etc .
SKF 99331 Speedi-Sleeve