Changing transmission fluid

[psychopathy]

I've got an 03 Pathy SE with 151,000 miles on it...I've owned it since 60,000 miles. I've never changed the transmission fluid. Had no problems whatsoever with the transmission...fluid looks fine...has proper level and all. I've read that if it's went this long...not to change it as it may mess it up. Opinions?

[Towncivilian]

"Changing the transmission fluid in a high mileage transmission will blow it up" is an unfounded myth perpetrated by owners of vehicles with failing transmissions changing the fluid in an attempt to fix things, then the transmission dies on them a week later. They blame the fluid change, not their severe neglect of maintenance. The transmission died because it was already on its way out.

Since your transmission is in good operating condition, go ahead and do a pan drop and strainer change (preferable) and then a few drain and fills with a few weeks of driving in between, or if you do not wish to do a pan drop, four drain and fills should be good. Drain & fills rather than a complete fluid exchange will gently clean things up.

Torque spec for the transmission drain plug is 22 - 29 ft/lbs. Replace the crush washer on the last drain & fill. Use Nissan Matic D fluid preferably; if unavailable, use any fluid that claims to meet Dexron III specifications. I run Castrol Import Multi Vehicle (now renamed to Castrol Transmax Import Multi-Vehicle) and am happy with the shifting. Approximate drain & fill capacity is 4 quarts.

[psychopathy]

Thanks man! I've been pouring over this forum today and you see to be the authority on here...I'll go with the drain and flush method. How many quarts per change?

[Towncivilian]

I revised my post a bit, re-read it. I listed the drain & fill capacity (4 quarts).

If you haven't changed the differentials' fluid or transfer case fluid, now would be a good time to do so as well. Do you want some information regarding those too?

[psychopathy]

I've changed the diffs last spring....I would like the info on the transfer case. Thanks...

[Towncivilian]

Do you have the part-time or auto-mode transfer case? If you have the auto-mode, you'll have a selector knob under the radio area.

If you haven't yet, download a copy of the factory service manual. To save a copy of the FSM, right click -> Save As on every PDF, save them into a single folder, then use fwd.pdf to navigate.

Do you grease the driveshafts regularly? If not, grease them every oil change with an NLGI No. 2 lithium soap base grease.

[psychopathy]

I've got a part-time (shifter beside the gearshift)...
I'll do that with the PDF...I was looking at those earlier. You da man!

[Towncivilian]

Then your transfer case requires 2.32 quarts of fluid. You can use Nissan Matic D or equivalent Dexron III, or API GL-4 fluid (do not use GL-5 or dual GL-4 and GL-5 rated fluid). Don't mix the two. ATF is used in the factory. Torque for the fill and drain plugs is 18 - 25 ft/lbs.

You may want to skim the the general information thread if you haven't done so yet.

[9899pathfinder]

Just seeking a clarification after about an hour of reading here. Never have personally done an ATF drain & fill on my '03 QX4 but the dealer did one (flush, I think) a few years ago (about 30-40K miles.) I have done simple d&f on my Honda Odyssey's notoriously fragile transmission several times so I know the basics. Anyway, here's the question: some posters recommend a simple drain & fill and others recommend two D&F's, the latter being performed a few days or weeks after the first. I guess the advantage of doing two is that two drains will get more old fluid out. But if one is sufficient ( and then perhaps another periodically) then it would easier and cheaper (although the job in any case is not cost prohibitive).

What have you veterans of this site done, 1 or 2?

[Towncivilian]

You can't go wrong either way. Two would evacuate more old fluid as you know, but if the fluid is relatively recent and uncontaminated just a single drain and fill will be fine to replenish additives and get some fresh fluid in the system.

I would suggest installing an in-line filter to help keep the fluid cleaner for longer. The general information thread has information regarding an inline filter.

[9899pathfinder]

Thanks so much, Town. I looked in Gen. Info. and found many mentions about Magnefines but no specific installation instructions or tips. Do you know of link/thread with how-to's?

[Towncivilian]

I don't believe there's a how-to but you can see my trans cooler + Magnefine set up here: http://imgur.com/a/giVyz

The general info thread tells which cooler line is which, so you can just splice into the passenger side (return) line and leave the Magnefine there if you'd like. The Magnefine should be fairly shielded from the elements given the factory splash shield/wind deflector.