Hello,
I just finished replacing my transmission, differential, and transfer case fluid based on the information that I found on this forum and some other forums and I wanted to share my experience. These were done on an 08 FX35 AWD with 40,000 mi.
Transmission Fluid
After reading information on many other forums about what is the best way to change the transmission fluid, it seemed that the general consensus was to do 3 drain/fills within 1000 mi of each other. The drain/fill is an easy procedure, just need a 19mm socket to remove the drain plug (keep an extra crush washer around from the oil drain plug to use when you replace it). I captured 3 quarts and 750 ml (almost a 4th quart) from the drain. That was pretty constant over 3 drains. On the 3rd drain/fill the fluid was a nice red instead of the original brown. Have 12 quarts ready to do the job.
Differentials
Front/Rear Diffs were pretty easy to find and drain/fill. I got the fluid from the local nissan dealer (80W-90). Rear fluid was brown (rather than yellow) but not black. Front fluid seemed under-filled from the factory. Was light brown. Probably didn't need to be changed except it seemed low. This makes some sense to me as I don't believe the front diff is actually used unless AWD is engaged, which is a tiny fraction of regular driving. Front diff required socket extensions to get to. Both diffs have female hex bolts that require you to have male hex fittings.
Transfer Case
I did this last because the nissan dealership and infiniti dealership got into an argument over which fluid I should use. The manual says to use Matic-D (as opposed to Matic-S or J for the transmission). I called up infiniti for Matic-D. They said they didn't sell it (I wonder what they'd have put in my transfer case if I'd asked them to do it), and that I should call Nissan. Nissan said they sell matic-D but that I should use 80W-90 for the transfer case. I told them the owners manual said Matic-D. They called a different infiniti dealership and asked and couldn't get a straight answer. The told me to double-check before putting Matic-D in the transfer case because they really really really thought it should be 80W-90. I told them I thought they were wrong about bought the Matic-D fluid. Then I went to a different infiniti dealership (LA has a lot of infiniti dealerships) and asked them what I should put in the transfer case. I waited at least a half hour. When the tech came back he had the owners manual and pointed to the differential oil (80W-90). I directed him one line lower to the transfer case oil (Matic-D) on the sheet he was holding. I said "Matic-D right?" he said... oh, yea.
Matic-D is basically transmission fluid. For the uninitiated that's watery fluid, less viscous than motor oil. 80W-90 is gear oil - it's thick stuff! Way thicker than typical motor oil. I have a horrible feeling that I'd have gotten 80W-90 in my transfer case if I'd asked Nissan to do the service. I think infiniti would have gotten it closer, but I doubt that they'd have had Matic-D to use and would have put Matic-S in it. Either way, across 3 dealerships (two infiniti and one nissan), I suspect I'd have gotten the wrong transfer case fluid!
Once I finally got to changing the transfer case fluid, the service manual said to just do a drain and fill just like the diffs, except that it doesn't show where the fill plug is. Luckily others have addressed this issue online. The manual also says to protect the exhaust from fluid spillage when you open the drain plug. I thought to myself "that's for newbs, I've already done the transmission and differential, how bad could it be?". But I listened to the service manual anyway and wrapped a t-shirt around the exhaust pipe before opening the drain plug.
The drain plug on the transfer case is a little odd. It's a square fitting that you can put the half-inch drive on your ratchet directly into, no need for a socket. This was not great for me since my small torque ratchet was a 3/8" drive, so I needed to put an adapter on it to get it up to 1/2". The adapter barely fit into the space available due to the exhaust pipe being right there. I tested this out before I opened the drain plug with a regular ratchet.
Once the drain plug came off, fluid exploded all over everything (soaking the t-shirt I had wrapped around the exhaust). I was very glad I had put something on the exhaust. The fluid that came out of the transfer case was bright red transmission fluid. So Nissan was totally off-base with 80W-90. The fluid really did not need to be changed, it looked great. Oh well.
One last bit, when replacing the drain plug I had my torque wrench set to 28 ft-lbs. Unfortunately the transfer case (unlike everything else on the car) requires 22 ft-lbs. As I tightened the bolt it just kept getting spinning further and further in. Rubber bits started coming off of the soft fitting around the bolt and I realized I was over torquing it. I checked the specs and sure enough I had over done it. So be careful when you do this one, you can over torque it by a little and it'll just keep spinning.
Final Notes
I did all of this without jacking up my fx. I don't know if the tire diameter is any different, but I have the sport package with 20" wheels that might give me a little more clearance. I apparently don't use AWD enough to warrant changing the front diff or transfer case at a 40k mi interval. I'll probably change it that often anyway just to make sure, but it's overkill. Definitely wrap the exhaust when you drain your transfer case... and you will probably smell burning oil when your exhaust heats up the first time anyway (I did). Triple check what transfer case fluid the dealership is using before you let them do it.
That's it. Thanks for reading.
I just finished replacing my transmission, differential, and transfer case fluid based on the information that I found on this forum and some other forums and I wanted to share my experience. These were done on an 08 FX35 AWD with 40,000 mi.
Transmission Fluid
After reading information on many other forums about what is the best way to change the transmission fluid, it seemed that the general consensus was to do 3 drain/fills within 1000 mi of each other. The drain/fill is an easy procedure, just need a 19mm socket to remove the drain plug (keep an extra crush washer around from the oil drain plug to use when you replace it). I captured 3 quarts and 750 ml (almost a 4th quart) from the drain. That was pretty constant over 3 drains. On the 3rd drain/fill the fluid was a nice red instead of the original brown. Have 12 quarts ready to do the job.
Differentials
Front/Rear Diffs were pretty easy to find and drain/fill. I got the fluid from the local nissan dealer (80W-90). Rear fluid was brown (rather than yellow) but not black. Front fluid seemed under-filled from the factory. Was light brown. Probably didn't need to be changed except it seemed low. This makes some sense to me as I don't believe the front diff is actually used unless AWD is engaged, which is a tiny fraction of regular driving. Front diff required socket extensions to get to. Both diffs have female hex bolts that require you to have male hex fittings.
Transfer Case
I did this last because the nissan dealership and infiniti dealership got into an argument over which fluid I should use. The manual says to use Matic-D (as opposed to Matic-S or J for the transmission). I called up infiniti for Matic-D. They said they didn't sell it (I wonder what they'd have put in my transfer case if I'd asked them to do it), and that I should call Nissan. Nissan said they sell matic-D but that I should use 80W-90 for the transfer case. I told them the owners manual said Matic-D. They called a different infiniti dealership and asked and couldn't get a straight answer. The told me to double-check before putting Matic-D in the transfer case because they really really really thought it should be 80W-90. I told them I thought they were wrong about bought the Matic-D fluid. Then I went to a different infiniti dealership (LA has a lot of infiniti dealerships) and asked them what I should put in the transfer case. I waited at least a half hour. When the tech came back he had the owners manual and pointed to the differential oil (80W-90). I directed him one line lower to the transfer case oil (Matic-D) on the sheet he was holding. I said "Matic-D right?" he said... oh, yea.
Matic-D is basically transmission fluid. For the uninitiated that's watery fluid, less viscous than motor oil. 80W-90 is gear oil - it's thick stuff! Way thicker than typical motor oil. I have a horrible feeling that I'd have gotten 80W-90 in my transfer case if I'd asked Nissan to do the service. I think infiniti would have gotten it closer, but I doubt that they'd have had Matic-D to use and would have put Matic-S in it. Either way, across 3 dealerships (two infiniti and one nissan), I suspect I'd have gotten the wrong transfer case fluid!
Once I finally got to changing the transfer case fluid, the service manual said to just do a drain and fill just like the diffs, except that it doesn't show where the fill plug is. Luckily others have addressed this issue online. The manual also says to protect the exhaust from fluid spillage when you open the drain plug. I thought to myself "that's for newbs, I've already done the transmission and differential, how bad could it be?". But I listened to the service manual anyway and wrapped a t-shirt around the exhaust pipe before opening the drain plug.
The drain plug on the transfer case is a little odd. It's a square fitting that you can put the half-inch drive on your ratchet directly into, no need for a socket. This was not great for me since my small torque ratchet was a 3/8" drive, so I needed to put an adapter on it to get it up to 1/2". The adapter barely fit into the space available due to the exhaust pipe being right there. I tested this out before I opened the drain plug with a regular ratchet.
Once the drain plug came off, fluid exploded all over everything (soaking the t-shirt I had wrapped around the exhaust). I was very glad I had put something on the exhaust. The fluid that came out of the transfer case was bright red transmission fluid. So Nissan was totally off-base with 80W-90. The fluid really did not need to be changed, it looked great. Oh well.
One last bit, when replacing the drain plug I had my torque wrench set to 28 ft-lbs. Unfortunately the transfer case (unlike everything else on the car) requires 22 ft-lbs. As I tightened the bolt it just kept getting spinning further and further in. Rubber bits started coming off of the soft fitting around the bolt and I realized I was over torquing it. I checked the specs and sure enough I had over done it. So be careful when you do this one, you can over torque it by a little and it'll just keep spinning.
Final Notes
I did all of this without jacking up my fx. I don't know if the tire diameter is any different, but I have the sport package with 20" wheels that might give me a little more clearance. I apparently don't use AWD enough to warrant changing the front diff or transfer case at a 40k mi interval. I'll probably change it that often anyway just to make sure, but it's overkill. Definitely wrap the exhaust when you drain your transfer case... and you will probably smell burning oil when your exhaust heats up the first time anyway (I did). Triple check what transfer case fluid the dealership is using before you let them do it.
That's it. Thanks for reading.
