High Mileage Transmission Flush

I'm 17 and have a 2007 Tacoma with nearly 270k miles on the original engine and transmission. I was given the truck from my dad and the transmission has never been serviced or flushed. I've been reading around and talked to my automotive teacher, and I've gotten a lot of mixed viewpoints and opinions as to if I should flush, drain and refill, or leave it alone. I've read that if the fluid is sludgy new fluid may cause it to slip, and I've also read that I should change it, but I'm 17 and don't want to have to buy a new or rebuilt transmission because I don't have tons of money yet and want to put it into mods. If I could get some opinions from some people with experience or have dealt/done this, that would be greatly appreciated.

Edit: I just realized I forgot to mention it's an automatic transmission

 

Drain and fill, I would leave it if its been that long though.

 

If you’re going to drain and fill, might as well do it 4 to 5 times, maybe more. Maybe someone can chime in for how many drain and fills gets close to recycling the old fluid out, and new in. Just a thought.

 

If it's made it this long, I'd probably leave it alone. It would be one thing if you were at 100k, then I'd say just drain and fill once to see how it goes but at nearly 300kmi, I wouldn't touch it. Just drive it and save your money. Treat that old lady good and don't beat on her too hard and it'll keep going.

Theres a guy on YouTube who went over 1 million miles in his 2nd generation Tacoma. He says in an interview he never changed the transmission fluid.

Send it!

 

Nothing to do with the transmission (well there is some helpful info on that here as well) but this will help you out in other ventures OP.

 

I don't know the validity to this, but I've been told that if you make it to 150k and haven't done it, don't, that it will make it worse. That fluids part of the transmission now, changing it makes things worse.

I guess.

I don't know if that's true or not, but at 275k if that's true, I wouldn't touch it.

 

There are no upsides to changing it, and maybe a lot of downsides. Drive it till the transmission dies and have it rebuilt by a shop that knows what they are doing. Chances are VERY good you're good for at least another 100,000 miles.

If the clutches inside the transmission are in good shape changing it won't hurt a thing. But if they are worn past a certain point new fluid is TOO slippery and the clutches will start slipping and you'll have a dead transmission within days of changing it. Keeping the old fluid buys you time, maybe a lot of time.

Since you have no way of knowing how worn the clutches are until you tear the transmission down it isn't worth the risk. Remember, you never get all of the old fluid out anyway. Roughly 1/2 of it. The new fluid mixed with 275,000 mile fluid will be just as dirty in no time. Like taking a bath in dirty bath water that 10 other guys used before you by only draining out 1/2 the water and replacing it.

I've never changed it on any vehicle I've ever owned, and I started driving 50 years ago. With a life expectancy of around 400,000 miles for most transmissions I'd literally spend just as much on transmission changes to get me to 400,000 miles as it will cost to have it rebuilt at 400,000. And I've never seen any evidence that changing it prolongs transmission life. Even if I did change it every 30,000 miles, I'd still be rebuilding at about the same time. Better to just save your money.

 

Changing the fluid “correctly” doesn’t cause any problems. The only thing the fluid will do is bring the problem to your attention.

I also understand that you are 17.
I know you would rather spend the money on mods. But those mods won’t get you down the road. I’d recommend spending money on maintenance first.

 

Being it's nearing 270k miles, I would at least check to see if it's at the correct level.
If it's low add the Toyota OEM fluid. Don't mix. And if you decide to do a drain and fill use the Toyota OEM fluid. With that many miles, I don't think I'd do a complete fluid change, maybe just some drain and fills over time.
You'll find many opinions on here.
I did a complete fluid change using the return line method on the forum at about 55k miles, but I used Valvoline Max Life.

 

Just do a pan drain. That’s about 25% on what the tranny holds. Next yr.you can do it again. This is the safest method. Just use toyota original fluid. Probably what’s in there now. Spend some time reading the correct procedure and you will be fine.

 

Transmission fluid change questions you will never get a straight answer. Your just going to have to do it or not and find out for yourself.

 

Yea I think I'm going to drive it for a year or so since I'm still learning how the truck drives and handles and see how it holds up throughout that time and not mod it for that time period and if the transmission goes out hopefully I'll have enough money saved up to buy a new one or rebuild it.

 

How long do you plan on keeping the truck for?

 

If it were mine I'd at least drop the pan, clean out the sludge, replace the pan gasket and filter, fill with fresh fluid and 3.5 ounces of LubeGuard Red. If it operates good then do a drain and fill 3 more times over a few months and use 3.5 ounces of LubeGuard Red each time. With proper maintenance and driving I believe these transmissions will last over 500K miles.
Hopefully your dad drove it like an old man and it lasts a few more years.

 

I'm not planning on getting rid of it for a while. I'm a junior in high school right now and I'm going to try and keep it through college and hopefully longer. It's been great to my dad and I and it's been a great first vehicle. I'm a very large Toyota fan and my dad just purchased a 2022 Tacoma TRD Sport 4WD.

 

If it shifts fine a drain and refill won’t hurt anything . Do that a few times and most tif the fluid will be cleaner. Just use Toyota fluid

 

@mtbmatthew8 I struggled with this too recently. I bought my 2010 with 289K on it (now at 305K) from the 2nd owner who had it since 40K. He never changed any fluid other than oil. After all the reading I did, I decided the best thing was to make sure it has the proper level of Toyota fluid in it and just drive it. Honestly I was on the fence about it until I watched the below video.

https://youtu.be/jJr30r6RRgw

 

If you plan on keeping it and its currently functioning proper, if i were you id: Drain the pan, drop the pan, clean the magnets, replace the filter screen. Button it back up. Fill with toyota WS and do the proper procedure to swap out all 11ish quarts of fluid.

There is a DIY on here on how to do a proper full fluid swap (not a powered flush).

 

Ok thank you so much. That's a great resource and it's nice getting an opinion from someone who's had the same dilemma as me. I greatly appreciate it.

 

I would replace the ATF filter and evaluate the contaminate makeup on the magnets and pan. Gooey black material is normal and you can feel confident doing a drain/refill. Visible metal flakes or pieces of clutch material is bad.