Oil Filter Gasket on Transfer Case (2003 Pathfinder)

[maltice]

Hi, I noticed a leak coming from my transfer case where the Oil filter screws onto the transfer case. I wasn't aware this was an oil filter until I read the repair manual but I was hoping this fourm could help point me in the right direction to figure out what part to buy in order to pull the filter cap off and replace the gasket.

Here is a couple links of the part I am referring to. You can see where it is leaking. Anyone ever pull this off to replace the gasket (or even the filter cap itself?

https://drive.google.com/file/d/1kaHCuL ... sp=sharing
https://drive.google.com/file/d/1HktCui ... sp=sharing

[mdmellott]

I could be mistaken, but I'm not aware of oil or ATF filters on any R50 Pathfinder transfer case. I think what you're looking at is the transfer motor on a All-Mode 4WD transfer case, not an oil filter.

[mdmellott]

Yep. My mistake. I do see an oil filter on page TF-49 https://www.nicoclub.com/service-manual ... 3%2Ftf.pdf This is an All-Mode 4WD transfer case, like I thought, but I wasn't aware of the filter. Page TF-155 has the removal and installation info. There is a o-ring that needs to be replaced to stop that leak. It's Nissan part number 33157-0W415. Get it from a dealership for $7.48 to save time and money compared to other sources that would charge that much just for shipping. Do not damage the filter in the process of installation and removal. This does not appear to be the type of filter that needs to be replaced like disposable motor oil filters or transmission filters.

[mdmellott]

I was wrong, again. (regarding the o-ring part number) There are actually two o-rings in this oil filter assembly. The complete assembly (15208-0W42B) costs more than $200 from a dealership, so again, be careful removing and reinstalling it. The two o-rings are part numbers 15226-0W420 and 15226-0W421 which cost $9.47 and $7.72 from Nissan. It looks like there are three small bolts holding the filter assembly onto the transfer case, as you can see in the image I pulled up at Nissan Parts Deal. https://www.nissanpartsdeal.com/parts-l ... m=333_B001

[maltice]

Holy cow, thank you so much! I was resigned to thinking I would end up having to replace the entire transfer case for some reason.

Again, much appreciated but I do have a couple more questions! Would you think if I removed this oil filter that I would only lose minimal transfer case oil? I am thinking that oil is only pushed through this filter via pressure when the car is running but then again, I'm afraid if i remove the filter, fluid is just gonna start dumping out.

Lastly, is it possible to check the level of the fluid in the case? I found a video of someone changing this fluid (https://www.youtube.com/watch?v=tyjWzSyWUF0) but it doesn't look like my exact case and tbh, I've never messed with a transfer case before and it scares the hell out of me.

Thanks in advance.
-m

[mdmellott]

You should drain the transfer case before removing the oil filter. Judging from the images in the service manual I linked to above, it looks like the ATF is going to dump out of the filter mount opening if you do not drain it first. It's likely past due for a change anyways. The video you linked to is close enough to show you what you need to do to drain and fill your transfer case. The only detail I could point out is that the fill and drain plugs take a 13mm square drive to remove them. You might get by using a 1/2" square drive as shown in the video you linked to but if the plugs are stuck in their threads so tightly that you need a breaker bar to remove them, you could end up wrecking the plug by rounding out the square in the plugs with the undersized 1/2" (12.7mm) square drive. I recommend getting the proper tool for the job. https://subimods.com/universal/tools/co ... ocket.html The plugs on the rear differential are the same so this tool will be useful for that as well. Try a 1/2" square drive first but if it feels like the plug square is starting to round out while you are trying to wrench it out, stop before you wreck it and then get the proper tool.

[mdmellott]

Don't be scared. You can do this.

[maltice]

Well, I guess this is next weekend's project. Thanks a ton for the help and suggestions (I'll def pick up the 13mm square drive since I don't have a 1/2" anyway). This should be a hoot and I'll report back for anyone interested in this thread in the future. Hopefully I got what I need to pull this off... just gotta figure out best way to fill up with the new transfer case oil!

[maltice]

Well, quick update here.. Managed to get these O-Rings and was about to do the job this past weekend and the square drain plug is smaller than 13mm and 1/2" is too big as well! I think it may be 10mm as 11mm is too big and 3/8" is too small. I don't have an 10mm square socket though and I can't seem to find in the manual where it specifies the exact size.

Anyone know what size these plugs would be if there aren't 13mm and or confirm it is a 10mm?

[VStar650CL]

If they're 11's then a 7/16" SAE will be a good fit, it's only about 0.004" larger.

[maltice]

Just updated my post.. I am pretty sure its a 10mm actually (my memory was off in terms of which sockets I had and tried)!

[xeoto]

Well, I guess this is next weekend's project. Thanks a ton for the help and suggestions (I'll def pick up the 13mm square drive since I don't have a 1/2" anyway). This should be a hoot and I'll report back for anyone interested in this thread in the future. Hopefully I got what I need to pull this off... just gotta figure out best way to fill up with the new transfer case oil!

[mdmellott]

Well, I guess this is next weekend's project. Thanks a ton for the help and suggestions (I'll def pick up the 13mm square drive since I don't have a 1/2" anyway). This should be a hoot and I'll report back for anyone interested in this thread in the future. Hopefully I got what I need to pull this off... just gotta figure out best way to fill up with the new transfer case oil!

Third post today of a copied previous post, and an added link to a site in Viet Nam on two of them.

[Rogue One]

Well, I guess this is next weekend's project. Thanks a ton for the help and suggestions (I'll def pick up the 13mm square drive since I don't have a 1/2" anyway). This should be a hoot and I'll report back for anyone interested in this thread in the future. Hopefully I got what I need to pull this off... just gotta figure out best way to fill up with the new transfer case oil!

Third post today of a copied previous post, and an added link to a site in Viet Nam on two of them.

Thanks for the heads up. He's been tossed out the airlock.

[mdmellott]

Thanks for the heads up. He's been tossed out the airlock.