schmoozer

I normally like to change my oil every 6 months, which usually equates to about 5000 miles (Mobil 1). Last time I changed it was in May and I'm up to about 8,000 right now if I remember correctly.

Normally I do a drain and fill of the transmission, and the oil at the same time, but I started thinking that this might be overkill. I know many recommend NOT to do a flush, but rather 3 drain and fills over the course of a few days. Well I don't really have the resources to be persistently changing fluids (apartment complex ) and thus opted to change the tranny fluid along with the oil.

So my question is: am I'm changing the transmission fluid it too frequently, just doing one drain and fill at a time every 5,000 miles, or if this is a good method to keep to?

tomf

A drain and refill every 25K miles is plenty in my opinion. (That's what I do and I use the cheapest Dexron III fluid available.) Especially if you consider that on newer cars, Toyota doesn't even recommend changing the fluid until 100K miles.

Remember, a transmission is basically a closed system, unlike an engine where combustion by-products contaminate the oil. So in theory, no contaminants should be introduced into the transmission and hence, in theory, there is no need to ever change the transmission fluid. Of course, theory and reality are two different things. In real life, transmission fluid does become contaminated but nowhere as fast as engine. 5000 mile drain and refills is way overkill for normal everyday driving.

Our transmission doesn't even have a real filter like you would find for engine oil. (Yes, I know there is something called a filter but it's more of a screen) If you are worried about contaminants you could add a Magnefine filter or if you are really concerned you could add a bypass filter. Neither is necessary.

PFB

Give the money to charity instead of wasting it.

hypervish

Do one drain and fill every 25k miles.

BDSL

Read your owner's manual.
I believe my 97 ES300 owner's manual states every 15k miles.

tomf

Acording to my owner's manual: inspect every 15K.
replace every 15K if you drive under "special operating conditions" see p. 70

So for normal driving there is no transmission fluid change interval. You just inspect it and if found lacking then replace.

speedkar9

5K transmission oil changes? Overkill.

Reminds me... I have yet to change the tranny fluid in my cars, I'm still on the same fluid I bought them with.

Here's a good DIY on how to do a flush (probably not recommended for older vehicles):

http://www.toyotanation.com/forum/10...lush-pics.html

brucelee1

iTrader: (2)

I do it once a year (about 8K miles).

Seems fine.

mitmaks

I changed it once on our 96 ES300 with 186,000 miles. You only change it when it starts getting dark color/smells burnt and/or to top it off. ATF lasts very long time, no need to change it every 5-10K miles.

schmoozer

I think in my mind was going with the replace every 15-25K miles, but remember reading that a drain and fill only replenishes about 1/3rd of the entire system. So I just took the 15-25k and divided it by 3 and it came out to about the same schedule as the oil.