Hi all. I was planning to flush and change my transmission fluid in my '04 Max, but I have now seen it several times people saying do not flush just change the fluid. Why is this? Is it because the filter is sealed and flushing will simply cut sediments/contaminents loose? I suppose I should talk with my local tranny guy who was going to do the flush and fill to see what his take is on this, but I welcome all feedback from guys here who know. Any explanation will be helpful as I am by no means knowledgeable enough to know the reason on my own.

 

I drove it to 131,000 never having changed it and never had an issue. Its a 'sealed' unit and changing isnt mandatory and after a certain number of miles its actually very bad to do is my understanding.

 

You have a 4at so I would avoid doing any flush at all to it. If its working fine just leave it alone. These transmissions are fussy and fragile as hell.

 

There are 3 kinds of "flushes".


First, is the drain and fill. Drain plug goes out, trans fluid drains, pan drop, clean magnets off and screen or filter clean / change depending on the car, replace gasket, put pan back on and refill to proper level. This gives you about 40 percent new fluid.

FLUID EXCHANGE METHOD... like dialysis for your car. This is adding new fluid while the old drains out. Uses your own tranny pump and not a machine. Gives you about 95 percent new fluid.

Flush machine. THE BAD ONE. DO NOT USE. Shop drains trans fluid and uses pressure and harsh chemicals to clear trans out. This process is the one that will likely eff your trans up by dislodging particles.


I did my 99 at 142k miles, AND my old pontiac with 195k with the fluid exchange method, worked just fine both times.


Changing fluid either with fluid exchange or drain and fill will NOT make a bad tranny good...if your trans is already shot, it's not gonna get cured by a fluid change.

 

I have the 5at.

 

On an 04 SL? Thought they only came with 4 speeds on the SL.

 

No, either the 4 or 5 apparently. Mine is a 5 though

 

Nope you're right only 5 speed AT's on 04's. My friend had an 04 with no auto manual shifter so I thought they were all like that. Maybe his was an early model idk. Weird

 

Yap, the 04 SL come in both 4AT and 5AT. What is the state (colour) of your fluid? Red, Brown, Black. If red, leave it; if brown drain/refill; if black, flush it. So long as the internal components of your tranny (i.e. no slippages) are still intact, it's safe to flush if your fluid's gone black.

 

Thanks Costee. My Max only has 32K miles on it, so i believe my tranny still will have a lot of life left, but i want to be proactive and change out the fluid to try to maintain it carefully since ours are so fragile.

 

And 04 with 32k on ?
What do you daily drive to keep the miles so low?

 

I bought it used in November (one owner) from a local dealership. It appears to have been a long term lease for someone in a Parish near Germantown, PA. I assume it may have been the head priest at the parish who used it only sparingly. The Carfax was clean as a whistle which put my mind at ease. That being said, my wife and I typically only put 8K miles/year on our vehicles. But this one averages out to about 4K a year which is ridiculously low.

 

I wonder whether the ATF has ever been changed. If not, I think you should; it sure needs to be refreshed after 8 years.

 

I had min done at 15K and then at 30K when I had my 04 max and never had an issue and just had it done on my 07 M35x 200$ at the dealer but well worth it

 

Just drain and add the correct amount new fluid. Auto trannies MUST NOT be flushed or do a fluid exchange in it. The gears will be fine but the seals will be damaged. Even the fluid is black, don't do more than the drain-refill method. You just have to do it every couple of miles to GRADUALLY renew the fluid. Auto trannies use hydraulics and sealing is a big part of it. If you would think about it, there are no contaminants inside an auto trans because it's a sealed unit unlike the engine, it takes in air, mix it with fuel, burn it, then contaminants were formed. In an AT, it would just have little friction materials from the clutches and little shavings. You only flush the system and replace the filter if you're doing an overhaul. I would recommend not to drop the oil pan (which is the inspection pan) and then clean it because the next time the tranny malfunctions and when you drop the pan to see what happened, it will be hard to tell what's wrong unless you take the tranny apart.

 

Nissan does not recommend doing trans flushes.

 

Drain and fill. NO FLUSHING. no jiffy lube machines, no quickie oil change places, they prob will use a power exchanger that may blow the seals.
WHAT TO DO IF YOU WANT TO DO IT RIGHT: Use 2 clean identical milk jugs. Drain in first jug. Mark level on a jug with permanent marker. Put 2nd jug right next to 1st on flat surface. Put a mark on 2nd jug right at the same level adn fill witu new fluid/ THIS IS YOUR CORRECT AMOUNT > Fluid out equals fluid in. No messing with dipstick.

 

Flushed my 4sp tranny and replaced tranny filter is running better than ever before so much smother and faster shifts

 

Thank you gentlemen! As always the Maxima men came out in full force to help answer the question of a fellow owner who obviously knows a lot less than you guys. I appreciate all of the feedback!

 

Hey Doc. You hit the nail on the head re: flushing your tranny and dislodging sediment from the inline filter. I have talked to countless people re: this, and in the end, I just drained it, put new stuff in, drove around for 10-15 minutes, and repeated the process. I ended up drainind/driving, draining/driving, and now it is so clear, you have to look closely at the dipstick to see the fluid. Some folks do this more than twice, but I only have 45k miles, so was able to just do it as described. I used roughly 1 gallon. A 2 gallon jug from Amsoil cost me $86, and the shifting really smoothed out. Also was the easiest job I have ever done under a car.

 

Doc, one more thing...Nissan auto transmissions HATE any kind of dirt. Just keep it clean, and try to change it out every 20-30k miles. Since it is such and easy job, it can be done in about an hour in your garage

 

Nice one.

 

If I did it over I would do at least every 30k. did mine twice at 60k, now just shy of 90k and was quite brown. Plus it was way low. Dry dipstick
So please check your level at least 15k, change if needed but certainly change by 30k.

So I am doing every 15k now especially with others' problems arising.

 

Thanks everyone. Change was done. As I am not mechanically inclined and don't have many chunks of time to spend doing even some simple things, my mechanic did it. he drained and filled three times until the fluid was clean and clear. I appreciate everyone's input.

 

I hope he drove it between flushes?

 

Hey Doc, if you ever get out here to Oregon, I'll do it for you for a couple of beers, and you buy the fluid.

 

He did. He drained, filled 3X and drove it in between.

 

Bruiser, if i ever get out to the left coast, i will come with a trunk full of fluid and take you up on that deal! Thanks brother...

 

drain and fill 3x in a row, drive a few minutes in between, and go on reverse.
then once a year.