Calling the Toyota transmission "sealed" is a bit of an overstatement. It's no more "sealed" than your differential or your transfer case. It has a drain plug, a fill plug, a check plug, and a breather to equalize pressure to keep from blowing out the seals. It just doesn't have a dipstick or a convenient way to fill it from the top through a funnel. Basically Toyota reconfigured it so that servicing it is much like servicing your diff or tcase, although because of the torque converter it's harder to drain out all the fluid. But that applies to the older auto transmissions with dipsticks as well.

I agree that it is in some ways symbolic, but the pr on it has developed into a different narrative. Certainly a trans has nearly always been less maintenance and monitoring, and more sealed than an engine itself, but it still requires changing at some point.

I think people on forums like this have a skewed way of looking at maintenance, because they are generally far more atuned to it than most people. I think if you did a poll of 4th gen 4Runners, or many other vehicles, who have had their vehicles for several years and are approaching high miles, very few would have had the gear oil changed in their diffs or would not know if it had been done by a mechanic along the way. My thought is few think about it much and either follow the recs of a mechanic, or simply never address the maintenance at all.

Engine oil and trans oil is pretty much all that has ever been asked of me when taking it to a shop. The first thing I did when I bought my 4Runner was to change out the drive line gear oils, because I didn't know if it had ever been done. I had records on the engine oil changes.

Let’s call the following items “gearboxes” in the 4th gen Toyota 4Runner:
- automatic transmission
- transfer case
- rear axle, colloquially referred to as “diff”
- front axle, also affectionately referred to as “diff”

Each of these gearboxes have drain plugs and fill plugs. Each have sliding and rolling elements, otherwise known as gears and bearings, bathed in liquid lubricant. These items transmit power, and by their nature wear over time. They do not last forever. A notion arises that these gearboxes are candidates for consideration of being the limiting factors in terms of maximum useable mileage of a vehicle. In other words, theconstraint to very high mileage.

Lubricant in gearboxes needs to replaced at some time. The confusion starts to enter the picture when the car company does not clearly address this. Automotive gearboxes are some of the longest lived factory original components on a vehicle, compared to, say, windshield wipers.

There is a question of whether it is in the interest of the car company, for them to provide drivetrain maintenance instructions so that vehicles last 300,000 miles and longer. It can be argued that it is not in the car companies’ interest for vehicles to stay on the road that long, rather it can be argued it is preferred by the car companies to sell new vehicles after, say, 125,000 miles or less. Hence the lack of clear cut maintenance documentation from car companies, and obfuscating statements by dealers and repair shops with language such as “sealed for life”.

That’s a fair point. If anyone has a better term for a no-dipstick design, fire away.

Interestingly, that oracle of knowledge called the owner’s manual doesn’t say not to change the fluid:

==
AUTOMATIC TRANSMISSION
Fluid capacity (drain and refill), L (qt., Imp. qt.):
Up to 3.0 (3.2, 2.6)

Fluid type:
Toyota Genuine ATF WS

Change automatic transmission fluid only as necessary.

Generally, it is necessary to change automatic transmission fluid only if your vehicle is driven under one of the Special Operating Conditions listed in your “Scheduled Maintenance Guide” or “Owner’s Manual Supplement”. When changing the automatic transmission fluid, use only “Toyota Genuine ATF WS” (ATF JWS3324 or NWS9638) to aid in assuring optimum transmission performance.

Notice: Using automatic transmission fluid other than “Toyota Genuine ATF WS” may cause deterioration in shift quality, locking up of your transmission accompanied by vibration, and ultimate- ly damage the automatic transmission of your vehicle.

Please contact your Toyota dealer for further details.
==

When was the last time you had the transfer case and diff's fluid changed?
If you wheel a lot and haven't changed them in over 30k miles, id say change the fluid.

Changed the Transmission fluid on my 03, 4 speed at 130k and 230k miles at the dealership. I'm at 236K now. Never had any issues with my transmission and I never towed anything.

You should have the transmission fluid changed at the Dealer and just confirm if its a flush or drain/refill and confirm the quarts needed for the work. I would guess they would do a flush, since its quick and easy.

FYI... My co-worker had a 2008 RAVE 4 and he never changed the transmission fluid on it and the tyranny died on him at 250k miles on the OD. It was his commuter vehicle and he also thought the transmission fluid was "Lifetime".

just got the tranny fluid exchange done at toyota. $230 (minus $30 coupon).

worst part was waiting over 2 hours. why i try to do my own work at home.

drive back was smooth. haven't added any shudder juice yet.

2005, 4.0, 298k.

Just did my in drain and fill and then I exchanged all the fluid using the cooler line up front, but I filled at the drain plug with a funnel and a long clear tube, looking down on the passenger side along the exhaust into the fill plug, plastic spring clipped the tube to the exhaust shied near the fill hole to secure it.

Fitting at top of radiator for transmission cooler is 3/8. Here was what I used, probably in plumbing supply at most retailers that sell plumbing supplies(Menard's here);

Here's my connection, black rubber tube going into the radiator will be the fluid that is pumped from the transmission;
3/8 inner diameter clear tubing, 3 feet
3/8 to 3/8 connector
Drain jug with 2qt and 4 qt levels marked
plastic spring clip (tube at jug)

Funnel set-up to fill from above (I've never used a pump);
Flo tool flex funnel(Walmart) + Less that 3 feet of 1/2 inch inner diameter clear tubing(Menard's)
plastic spring clip (tube by fill hole)
Fill plug is 24mm, (if possible use breaker bar to loosen, or long wrench(knuckle buster...))

3 gallons Valvoline Maxlife (bought 4, one for stock being I didn't use it)

My method, learned from Sienna guy, add 1 extra quart, run the motor, drain 2 quarts, add 2, till the last time then just add 1 qt.
Time at 5:40 for fluid exchange, (ignore his jug on the topside, it's where you'd fill at, but he has a dipstick tube)
2009 Toyota Sienna Transmission Fluid Flush and Filter Change
YouTube


more details (I was going to keep this short...);

I must have started with the flex funnel somehow connected to 3/8 tubing going into the radiator, you should do this at first to clear the fluid out of the cooler if you use the top line in. Use any small funnel that connects to 3/8 tubing. The filling at the top cooler line (driver side) of the radiator goes so slow, you'll want to fill through the fill hole at the transmission, first I wanted to use the lower radiator line out, but it added difficulty and I wanted simple.

Initially, I left the drain plug off and just let 1/3 qt clean fluid chase down through the cooler (radiator) and drip out the pan to clear that part. I took the funnel off the clear tube and blew into the tube it was going so slow, that's when I opened the fill plug. To summarize, ran 1/3 qt through cooler, installed drain plug after it started to drip real slow.

Preferably get a new drain plug and gasket, and if the old plug is good keep it for a spare, mine is not perfect (next drain and fill will be replaced).

I used 11 and 3/4 quarts Valvoline Maxlife ATF. I open the transmission cooler line at the radiator I think I got maybe 7/10 of a quart out through the transmission cooler, measured after I drained the pan. I'm not sure of the total capacity, I thought 11 qts, somewhere in this thread I read 13 qts. Mine was noticeably red, as I saved before/after samples to show my buddies.

Change your fluid, I'd say at 30k to 40k it's gonna be dirty. Even if you're beyond whatever miles, because of the clutch plates and the friction material that wears off and you don't want that running through your solenoids clogging them up. It's basically a hydraulic machine, and Toyota transmissions are resilient from my experience.

Just adding dropped the pan and changed the filter last year, that's why I didn't get into that here.

If I haven't convinced you, try this;
Bob Is The Oil Guy
ATF, Differential, Trans, Brakes, P/S
ATF, Differential, Trans, Brakes, P/S - Bob Is The Oil Guy

Technically, that's a true statement given the cost of a transmission rebuild versus the value of the vehicle at 250K miles.

btw, i did have a sample of the old fluid saved. any use in getting it tested?

That would be up to you and if you want to known what the results would be.

So, here's my dilemma. Leaving on the 13th for a 1300+ mile road trip. Should I leave my trans alone (no known issues, shifts fine), do a fluid exchange or, drain and fill? AFAIK it is still on og fluid.

*Edit to add.
203k+ miles. Getting oil changed (it's due anyway) and getting radiator replaced (had for a while and just been putting of since it is a minor leak).

The dealer shafts you for real they charge you $200 to exchange what is in the transmission only so like 3 quarts worst rip-off in the world I would not worry about it if you want to change it do it I changed my car Lexus ES330 with 200,000 miles original transmission oil no issues at all and I did my 3rd gen 4Runner with 450,000 miles (unknown if it had been done before but it was very dark) with no issues at all so I think you'll be fine I would much rather have clean fluid in there then Super all black nasty stuff that's been in there from the factory.....

I'm sorry guy I don't mean to thread hijack but does anyone know the transmission pan gasket part number? I got one from RockAuto part number TOS 18736. It says Toyota truck 4 Speed 98 through 03. I assume it is not the correct one but maybe they didn't change them....

According to a quick search "Exact Fit for your 2005 Toyota 4Runner SR5
20-bolt holes; Aisin 70-50LE; 5 Speed; Aisin 70-50LF" it will fit my '05 v6.

THANKS FOR RESPONDING SO QUICKLY MAN!! that's what the RockAuto part I ordered was but the one I actually got says 98 to 03 4 speed but it is 20 holes so I'm just going to assume that they didn't change them between the four and five speed.... and thanks for allowing me to thread hijack I figured I didn't want to post a new thread for this one single question and you were talking about transmission anyway so it felt like it fit....