How to Drain/Refill Automatic Transmission

There is a trans temp indicator even if you have a 2WD. The indicator will not self check with initial key switch check. It will illuminate when you put trans into the OBDII(pin 4 to 13 jumper) diagnostic mode per manufacture tech instructions.(FYI, manufacture has a description error in info. It states the D shift indicator will flash(incorrect), It will be the RED A/Trans indicator if diagnostic tech instructions are followed exactly. This is only for the 750E & 750F transmissions.

 

thx

 

Has anyone actual talked to a Toyota tech to see if this trans temp light deal is really necessary? I have worked for Acura/Honda for 6 years and have seen transmissions come in way overfilled or way underfilled all the time. Rarely do the overfills cause a problem besides leaking axle seals (FWD) from time to time. Even the underfilled ones are usually fine unless they have been driving like that for more than 15k. With this knowledge I am assuming from my experience that draining and filling to the overflow would be more than adequate and less time consuming. Thoughts on this?

 

The whole thread pertains to the automatic transmission. The procedure and video in the initial post should answer all your questions.

 

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video for reference to where bolts are and how to fill, does not talk about getting to temp.

 

The procedure in that video is incorrect for several reasons and should not even be referenced other than to find the bolt holes. If you read the comments below, the dude doesn't even get the capacity of the transmission correct.

 

Has anybody used a Scangauge II to get the Transmission to temperature?

 

Nope, but have thought about it, just haven't tried to put it into diag mode, then watch the SG at the same time,,, yet.

 

great write up!! I'm steadily approaching the 60k mile mark.

 

I have a double cab 4x4 Offroad with the towing package.

I did mine at 86k.

This sealed transmission operating temperature BS has got everyone scared of nothing. This is an easy straightforward process.

I used the Scangauge II to change transmission fluid using the MountainLion method and pulled the pan for inspection. I learned some things in the process.

First of all it would be hard to screw up the fluid level. Someone on here asked why couldn't you just drive it until you reach operating temperature and then open the overflow plug.

I believe this would work just fine provided you feel confident that you have close to the right fluid level, because the transmission seems to stay between in the temperature range for the most part under normal driving and idling conditions.

All that you are doing it getting the fluid to operating temperature and letting it overflow over a standpipe. It really isn't any harder than using a dipstick.

As for pulling the pan to inspect the strainer and magnets, this is a very easy job. True you need to be a little knowledgeable so you don't over tighten those tiny bolts, bend the pan and cause leaks , but a reasonably intelligent guy should be able to handle this.

The gasket is rubber, requires no sealer, and is easy to line up, beacause you can see al the way around it.

I did not pull the strainer to inspect it because my transmission was very clean. I was satisfied by just looking at th screen and pan.

I am told that it can be cleaned using carburetor cleaner or parts washer if needed.

I had some very minor sludge on the magnets probably no more than from break in and the fluid looked great after 86k.

I think this is worth doing, as long as you use the MountainLion method and actually change a decent amount of fluid and I would recommend pulling the pan to see how things are going.

Just use a star pattern and extreme caution not to over tighten the pan bolts.

Thanks to everyone for providing so much useful,information!

 

Yes I just quoted myself for an answer to this.

 

Just did this today. When I pulled the check plug in the beginning (to make sure it could be removed) a bunch of fluid came out. Almost the same amount that came out later when I pulled the drain plug. If it's gone 70k miles being that overfilled from the factory, I doubt the fluid level needs to be that accurate.

 

Was the engine idling when you pulled the plug? Even when at the correct level, fluid will drain if the engine isn't idling circulating the fluid.

The majority of vehicles on the road with an ATF dipstick (if not all) requires the fluid be checked with the engine idling - just like Toyota specs for our AT with the overflow plug.

Not stating this is the case in your experience, just saying...

 

Good point. That would explain some of it. It was still a lot more than I was expecting. If my graduated bucket is accurate, the amount that came out was around 4 quarts.

BTW, thanks for the writeup.

 

Just my two cents. I have heard of alot of people with non-tacomas getting trans fluid changes done and their trans f'ed up afterwards. Mind you, some had it done at Mr.Lube. Alot of old timers say don't even bother changing auto fluid as you will always get problems afterwards. Just thinking how this could have some truth after hearing bad stories from co-workers. In any case, if you are going to do it i would go to a dealer, pay the extra, and make sure they can warranty their work. Just my opinion though, stay away from quick lube places and if you are not sure you can do it properly and refill properly don't risk it.

 

One of the theories is that by changing only a small amount at a time, it's less likely to "dislodge particles" or whatever the fear is with flushing with all new fluid.

 

Time Sert. I lie em better than a helicoil. But a helicoil will work. Just make sure to put a lot of sealant around the coil before you install it.

 

Just changed the fluid this past week using this DIY write up, well done Fortech, thanks!

 

How common is it for the factory to overfill? I just drained about 2.8 qts and it took just slightly less to fill.

 

I think it's been more common to find the At underfilled on the earlier models - but I guess anything is possible?

Did you have the truck idling when you pulled the overflow plug? I've performed this 5-6 times now and have always used around 3.1 quarts. I wouldn't worry about it too much as long as you did the procedure correctly.

My work truck leaks off about a quart of ATF every three weeks or so. If a quart low doesn't bother a chipped and exhausted Dodge Cummins, I don't think the Tacoma will mind 0.1 quart or so.