4.0 Automatic Transmission Service Recommendations

Yeah man... breather mod would be a good time to do that. Speaking of... I need to do that myself since it's pretty easy. Rear diff I only change every other oil change. Probably overkill but it isn't going to hurt anything either.

 

Holy shit, how often are you supposed to do it? And I have 2 sets of the parts you need to do the breather mod. The breather and new part that goes on the diff. I will send you a set for free if you would like

 

Honestly I'm not sure but I changed mine the first time at around 1000 miles just because. I would think 20k or so would be just fine. Thanks for the offer but I'm still trying to figure out where I'm going to run my tubing too. Most likely behind the taillight.

 

Sounds good but you still need the two pieces. Let me know I love giving away free extra stuff

 

Cool man thanks I'll let you know.

 

Toyota recommends "inspecting" diff and transfer case oil at 30k intervals, but only changing it at 30k intervals if you tow or drive off road (from the Toyota scheduled maintenance guide). I changed all of mine at 60k.

 

After 30K my rear dif and front dif looked gross but my transfer case looked brand new. Since we haven't had any snow the last two years I haven't used my 4WD as much as I used to. I replaced it with higher quality synthetic gear oil but Ill still probably swap out the rear dif fluid every 15K now.

 

this is why I love my GEN1 auto

 

It sucks because I don't know who to really trust. I wish I could do it myself, but I don't feel comfortable messing with a sealed transmission, so I don't know who to talk to.

 

It's super easy. Honestly, the hardest part will be removing the filler plug if it hasn't been opened before. Oh yeah, don't forget to drop the spare. You can leave it up, but my aftermarket one stuck down too far making it difficult to fill it up.

 

Your transmission is not sealed. If it were there would be none of the write-ups you see here for flushing and setting correct level. You are led to believe by the mfg. that in most cases you'll not need to change it. Depending on it's usage and mileage, that could be true. Not sure where this "sealed" thing got started.

 

Probably because it doesn't have a dipstick it is assumed that it is sealed.

 

I believe you are correct. I should have known better. I think that slipped my mind since all I think about now is jumping DLC3 pins, shifting in between 2 gears 'til I get a specific light blinking sequence, etc. etc. I forgot all about the stick.

OP - you have 2 choices. Read the posts here that cover this and DIY or trust the work to someone who may know little more than you.

 

As long as I don't have transmission fluid leaking under my truck it's sealed good enough for me

 

I am aware, but our transmissions are commonly referred to as sealed, which is why I used quotations when I initially said "sealed." There is no way to check the level or easily fill them if they are drained.

Like I said in the OP, doing it myself is not an option. Looks like I'm going to have to trust my local Toyota techs.

Thanks to everyone who replied!

 

In all honesty, a drain and fill on the transmission is pretty easy stuff.

Just ensure you can get the drain and fill ports loose before draining the fluid.

As for getting it into proper temp mode. Consider that if you did the drain and fill yourself it would save money. Use the saved money to buy a Scangage II. Program the Scangage to indicate transmission pan fluid temp.

Drain the fluid in the pan. Reservice it with about what came out and a little more. Start the truck and set parking brake. Shift through all the gears and hold it in each gear for a minute or so. Do this for about 10 minutes.

Shut it off and drain the fluid a second time. Refill, and again go through all the gears. This time once the Scangage indicates proper temp, remove the overflow, then let it trickle to the proper full amount.

Probably the most difficult part of this is adding fluid. The angle is just wrong to simply pour fluid into the transmission.

With a Scangage, I would rate this as a difficulty of maybe 3 out of 10. No Scangage, probably a 5 or 6.

If you buy the Scangage II, you will now have a nice engine monitor indicator. I use mine 100% of the time. Set for Trans fluid temp, MPG, Water Temp, and Intake Air Temp. The Scangage does a lot more, but I never use those functions.

FWIW, the fundamentals of changing a diff fluid are the same as the transmission fluid. Simply overfill and drain via a known proper level port until filled.

PK

Need to add, I have done my transmission fluid at around 20k, will be doing it again in the near future. I will do the complete drain and fill via the fluid return hose. The WS fluid that came out at 20k was pretty nasty.

 

I have been told that most automatic transmission "damage" occurs during the first 5,000 miles. By damage, I take them to mean filings/shavings produced during the transmission's break in period. Anybody else heard this? If this is correct, would it make any sense to do a transmission flush and fill at around 5000 miles to remove the filings/shavings?

 

I have a bunch of info at this link that can provide you with all the information you need for your A750 series transmission in your 4 litre truck
https://www.tacomaworld.com/threads...th-pics-for-second-gen-4-liter-trucks.289913/

 

Thanks Gearcruncher. I was hoping you were around. Very helpful info.

 

Alright, so after some conversations with service professionals and all of the helpful folks on this thread, I decided to have my local Toyota dealer do a complete flush. The consensus from the couple of mechanics I spoke to was that the filters in modern transmissions help to eliminate the risk of particles becoming lodged later dislodged when flushing, so that eased my mind.

I called my two closest Toyota dealers; one quoted me $260.00 for a full flush with Toyota's World Standard ATF and the other quoted me $210.00 for a full flush with Valvoline MaxLife ATF. After reading @gearcruncher's thread about the WS ATF, I went with the second quote because of the higher quality Valvoline fluid. The price was a bonus.

I picked the truck up last night and so far, the transmission feels great. I'll update this thread if anything explodes. Thanks again!