2001 QX4 Rear main seal replacement

[AU Qx4]

This is my first post on this forum, but I want to thank you all in advance for this valuable resource. I have fixed sooo many common problems with the tips and tricks posted hear.

My next project is to change the rear main seal by dropping the transmission and inspecting the area to determine if it is really the rear main seal or the rear oil pan gasket. I have read other say that if you are leaking when parked then it is the oil pan, however I park on a driveway with an incline and it does leak less when I back it in but it still leaks a lot. If it looks like a flow from the crank seal I can simply remove and press a new seal in without disturbing the pan seal.

My question for any Nissan mechanics or experienced motor heads out there, is: If I do need to pull the seal retainer, is there any way to install the new retainer rms/pan seal combo without dropping the pan?

If not, is it possible to loosen the rear 4 to 6 upper pan bolts and insert a plastic shim to gain clearance for the new seal/sealant?

The FSM has you disconnecting everything from the steering column and motor mounts, to dropping the suspension member and lifting engine from above. (which I might have to do any way to rock the engine back for access to the upper bell housing bolts) All this to drop the oil pan.

[yeldogt]

What oil are you using? I have owned 3 02 LE pathfinders .. they all leaked if I used 5W-30 synthetic oil. They did not leak if I used conventional .. especially the "high mile" oil. Same 5W-30 ........For whatever reason the rear main will allow the thin syn oil to leak when cold -- the high mile has conditioners that swell the seal enough for it to stop.

[AU Qx4]

I bought the Q with 50K on it and used mobil 1 syn for the next 50K. When I switched to 10w 30 the damage was done and has leaked with dino oil and a host of liquid leak stoppers. ie. Lucas leak stopper. I have had a 97 i30t with a rear main seal leak and a trans input shaft leak as well as a slow axel shaft leak (after the third set) (my father in law now drives that car with 230,000 on it and just puts up with the leaks), a 2001 I30 which just started leaking (wifes car) from the rms at 90k, and a 95 D21 v6 pickup with 120K no leaks.... I think Nissan needs to come up with a better design for the RMS!

[AU Qx4]

I think synthetic oil has its advantages, quite simply, it oxidizes at a higher temperature thus providing superior protection under high heat/stress situations. But... oil seals on cars are a PIA to change and I will continue to use it in my motor cycles but I will just use premium dino oil in cars and change between 3k and 5k.

If anyone can shed some light on the oil pan question I would be very grateful!!

[AU Qx4]

Still looking for advice on this oil pan lip seal question. Please chime in if you have done this before.

[PathyPop]

I don't think I can help on this, but if the upper pan gasket leaks does it come out the same weep notch opening that the RMS seal leaks from? I have a leak there but also have receipts from the prior owner that shows the pan and valve cover gaskets were all replaced, so I'm pretty sure it is the RMS. I don't think I've had another vehicle that they would leak through the same place.

[AU Qx4]

Yes, you can't inspect the upper pan seal until the bell housing is removed. The leak can be pan, rms or both.

[macgiver]

mac , before the BIG bucks , I've had surprising results with Valv Hi-mi on reducing "Seapage " to very tolerable levels,Vavoline has been sort of an "early pioneer" in the Hi-mi oil formulation and I'm believer in their "wear additive" for bearings(my #1 intake cam-lobe is MIRROR-LIKE at 260k ,as seen through oil fill ! ) And have witnessed the seapage/sweat reduction - could give it a shot ?

[AU Qx4]

Have tried the Valvoline hi mi and it did not help. I must have a tear or crank groove. I plan on using a speedi sleeve to correct the crank if it is grooved.
OK, after inspecting the new seal retainer more closely, it looks like the seal is pressed in from the back eliminating the possibility of just pulling the seal out without disturbing the pan seal. If this is true then I will def need to drop the upper pan.