I had changed the transmission oil a while ago (about 1.5years), and as time flew by and life slowed down recently I've had more time to devote to doing a full round of fluid changes again (with the exception of the oil, I kept that around the 5k mark). In that time I've put on over 50k miles. So I checked the transmission oil and it was dark.

question is, since I've started changing out the fluid the shifting seems a lot more "firm" or "stiff" or possibly another description is "harder shifts". Is this normal? I don't remember this happening the last time around.

When changing the fluid, the shifts SHOULD get more crisp. What fluid are you putting in there?

There have been cases where metal shaving come out with the fluid and thus the tranny doesn't feel the same as it did when the shavings were floating around in there.

I'm putting in Mobile 1 full syn ATF. The oil that came out didn't feel gritty or have noticeable shavings in it...just very dark in color. Close to the color of engine oil with a hint of red/pink...almost like the color of dried blood come to think of it

I have found the old Mobil1 ATF was not speced to JASO friction modifier levels. The new Mobil1 is formulated for JASO spec, it should be definetly better.

I would do frequent and drain changes to be sure there is nothing happening down there. I would drop the pan and see what is collected in the magnets as your description of color is quite scary. If you do intend to drop the pan get new magnets from stealership.

ATF discoloring to black is something I would definetly worry about and based on ur description of notchy shifting, I would even suspect something blocking in the valve body. Drop the pan, my friend....

it's definately the new Mobile1 formula.

As for dropping the "pan"... I certainly don't mind doing that...but I'm not quite sure where the pan is on my transmission. I know where the drain bolt is, and there is something that looks like a "pan" that is above the drain plug and toward the front. It's black, has... I dunno...10 or so bolts on it. I've taken that off last time and there were no shavings in it.

I picked up a gasket from Autozone...and it looks NOTHING like the black pan I mention above. The gasket is in fact huge...to the point that it actually looks like you have to take the entire side of the transmission off.

I ran across a picture of that black pan I'm speaking of, but for the life of me I can't find it again

- also...I didn't see a transmission fluid cooler on my car...I'm sure adding one wouldn't hurt, is there any particular one to get or does it really matter?

-edit- looking at the AT FSM, page 639, part # 49 is what I removed (Side cover). I assume the cover I need to remove is the Transaxle Case cover - Part # 1. Is this correct?

The transmission drain bolt is on the pan. The pan itself should have 20 odd 10mm bolts, be nice to them when u take then off and putting them back in.

Return the Autozone gasket (cork crap****tt) and get the OEM one. I did that mistake and resulted in leaks.

I recently had some of these same questions and have done some research.

The guy at autozone more than likely gave you the transmission pan gasket for the 4 spd and from the description it sounds like you have the 5 spd. Correct? Both transmissions were used that year, but the 4 spd is what comes up in Autozone's system.

If you have the 5 spd then the transmission oil cooler won't do any good because in this setup the coolant goes to the transmissiion (heat sink type setup) instead of the transmission fluid going to the radiator. There isn't a transmission line for you to hijack and run through the cooler.

If you have the 5 spd then you need Nissan-matic K or equivalent ATF. I'm not sure if what you're using is equivalent or not, but I advise you double check. It could explain the quick darkening of your transmission fluid. I'm going with Amsoil ATF this week. Pricey, but it's only every 30K so <shrug>.

I'll be under the car tomorrow so I'll verify some things and maybe take some pics to show what I was talking about.

As for the gasket, what AZ gave me looks like the shape of the pan that gets dropped and it's not made of cork, but a tough but plyable rubber (about 1/8" thick). Could a hi-temp silicone RTV type gasket be used in place when replacing the pan (like the FSM states to do with the timing cover)

I do have the 5speed AT. The Mobile1 full syn ATF is listed as being Matic-K equivalent as well.

As for the darkening...it could be that I'm around 10-20k miles over the 30k mark (long story with some very tough times).

ok, took some pictures of the area... and I swear I'm either crazy, blind, or something...because it looks nothing like any of the pans I've seen anyone talking about.



Someone please help clear my idiocracy

I guess that is NOT a bolt. I think you are better off putting this thread in the 6th gen forums.

If you don't have a bolt on the pan, then this might else be the drain bolt. Loosen it and see what exactly comes off it.

It's a drain plug. They recommend replacing a washer too. And I don't think it is very wise using anything but Nissan Matic-K ATF for 04 5AT Maxima SE.
I did my drain last month. It took exactly 5 quarts. And shifts seem to be softer.

After driving it a bit over the weekend the shifts have smoothed out a bit. They're not as "hard" as they were initially, but they're still fast and firm.

I plan on doing another fluid exchange today or tomorrow so I can get as much fresh ATF fluid as possible. The last change turned it from ugly to not so bad, the next change should get it to mostly the nice pink it's supposed to be.

As for the fluid, the Mobile1 full syn ATF as well as Amsoil fluid is listed as Matic-K equivalent or better and should be perfectly fine. Lots of people are putting Amsoil synthetic fluid in their AT and have no problems at all.

That is 100% sure the drain bolt. I have confirmed it in the Service Manual. I don't think you'll buy yourself anything by removing the pan off the side.

ok. The last time I did a fluid change I did remove that pan and there was hardly anything to be found there. Hardly any grit or shavings to speak of. Thanks

how do you know for certain those fluids are equivalents? From what i have seen nothing has matched Matic-K for the 5sp auto.

Amsoil ATF, Mobil1 MV ATF are a few that match Matic-K spec. There must be more, but then these are ATF's that are readily available OTC.

Read the owners manual. It says for the 5 speed to only use Nissan Matic K fluid. Anything else can cause transmission damage down the road. For the 4 speed the manual says you can use an equivelant. That is the transmission fluid drain plug. I've drained my fluid twice already with Nissan K fluid.

Amsoil/Mobil etc. make ATF that you can substitute for Nissan's crappy Matic K.

So are Amsoil & Mobil full synthetic or synthetic blends?

What's Matic K, full ATF no synthetic? Or is it a blend also?

Personally I prefer synthetic oil over regular oil, but I don't know much about transmissions, I'm starting to learn.

I wish you could leave posts like these on the 6th Generation threads, but the Admins see anything that look like fluids and drop it in here immediately. Each generation has its own issues (specially the 6th...), if we could leave threads like these there, that would be ideal to resolve these types of issues. Unfortunately the 'Fluids and Lubricants' threads get a whole less traffic than the generation threads.

Sorry Admins, I understand you guys do a lot of work behind the scenes, this is not the users against you, just constructive criticism.

I just posted a discussion about draining versus flushing an auto trannie on this thread on this site (post # 391):

http://forums.maxima.org/fluids-lubr...ml#post7777822

{This post tag now works properly. Sorry for the wrong link before.}

This post tells why doing a drain only changes about half of the fluid.
If you need the Nissan fluid, that would probably mean you need to find a stealership that has the flush equipment to end up with the proper fluid and a complete flush of the system.

Hey Silver, this may be the wrong link, it takes you to an engine oil discussion and post #391 is definitely not your post. Please re-link (did I just make up a new word...sad)

With the exception of one of the many diesel oils AMSOIL offers, all of AMSOIL's oils are full synthetics.

Matic K is a spec...either a petroleum or a synthetic based ATF can be formulated to meet it. My guess is that the Nissan-branded fluid you would buy from the dealership is petroleum based. AMSOIL (and others) offers a synthetic-based ATF that meets Nissan D, J and K specifications. I use AMSOL ATF myself and I sell a ton of it to our members.

Concerning partial drain versus a total flush, while doing a drain/refill only replaces a portion of the fluid, that is the process outlined in the various FSMs from Nissan and other OEMs. There have been some reports of people having transmission problems after they had their transmissions commercially flushed, specifically with one of the machines that reverse flushes the system and where the filter is not serviced. If you are set on flushing your system, the do it at home version is very well documented in one of the stickies.

A lot of info, but good!

Just for comparison, how much would it cost for Amsoil and Mobil1 for a full transmission change?
I'm not sure, but I believe is 11 qts or 15 qts can't remember right now.

Sent you a PM.

Got it, thanks.

Has anybody used Amalie Synthetic ATF? Any reviews?