How important are trans fluid changes?

[Mark R]

Just wondering, if these are still a good idea, even if the manufacturer doesn't list it as a service item.
I've got about 150k miles on my lexus IS250; and the trans seems to be working fine. However, there isn't even a dipstick or a fill port on the trans, so Toyota (or AW who is the actual OEM) clearly don't think that fluid changes are needed.

It turns out there a transmission shop down the road who could do a fluid/strainer change, etc. and obviously they recommend it, but they have a slightly different motive to recommend such a service.

I guessing the thing to do is leave it and not touch it; but synthetic or not, I do wonder about whether the fluid degrades with time and mileage.

 

[TridenT]

AW?

I don't know your year but it looks like the transmission is sealed for at least some years... So... don't bother.

 

[Mark R]

AW = Aisin Warner

Hmm. Thanks. Kinda guessed that probably not touching it is the best thing.

 

[mmntech]

I've heard you should do it every 20,000-30,000km. I'd say just check it and see if it's dirty, but you can't really do that. Weird that it doesn't have a dipstick.

What does the owner's manual say?

 

[Jimzz]

I do it every 30-60k. The trans fluid (and filter on some trans) is the life of the trans and keeping to changed can extend the life of a trans greatly.

 

[evident]

If your IS250 is like my RX350, it uses toyota's "world standard" transmission fluid, which on my car has no service interval. the transmission is sealed and not easy to do on your own. they claim the fluid is designed to never be replaced on the car unless driven in "severe" conditions.

we bought the car used around 30000 miles. around the 50K mark i asked the toyota dealer to do a drain and fill on the fluid really just for peace of mind- not sure how it was driven by the previous owner and just like to replace fluids over time anyways. It shifts a little smoother and imo it was worth it. If i were you i'd only get that thing serviced at a toyota/lexus dealership though. I wouldn't put any other type of transmission fluid in there and the toyota/lexus dealer should know what they're doing. fwiw it cost me about $80 at the toyota dealership including the fluid. the fluid itself is not cheap if i recall. I got a ton of other stuff done to the car at the same time though such as a full brake job and they were surprisingly reasonable.

 

[Yuriman]

I assume this is an automatic?

I recently did the MT in my Honda, got the fluids from the dealer for about $15 and it was as simple as changing the engine oil except I needed a hose/funnel to get the fluid to the fill hole.

 

[JCH13]

Sounds as if you have a sealed 'lifetime' trans. You shouldn't need to flush it or change fluid unless you've ever tripped the 'ATF Temp' warning.

 

[rommelrommel]

If your IS250 is like my RX350, it uses toyota's "world standard" transmission fluid, which on my car has no service interval. the transmission is sealed and not easy to do on your own. they claim the fluid is designed to never be replaced on the car unless driven in "severe" conditions.

we bought the car used around 30000 miles. around the 50K mark i asked the toyota dealer to do a drain and fill on the fluid really just for peace of mind- not sure how it was driven by the previous owner and just like to replace fluids over time anyways. It shifts a little smoother and imo it was worth it. If i were you i'd only get that thing serviced at a toyota/lexus dealership though. I wouldn't put any other type of transmission fluid in there and the toyota/lexus dealer should know what they're doing. fwiw it cost me about $80 at the toyota dealership including the fluid. the fluid itself is not cheap if i recall. I got a ton of other stuff done to the car at the same time though such as a full brake job and they were surprisingly reasonable.

x2.

I just had my GX470 done at Toyota. It was reasonably priced for peace of mind, although the fluid is "lifetime" rated.

 

[BlitzPuppet]

I run the general rule of if it hasn't been changed and is over 80K I don't touch it. Had two transmissions act up only after the fluid was changed...and one completely died on me.

 

[BUTCH1]

There's no dipstick on GM either and hasn't been since '98. Manual calls for a fluid change@100K or 50K for "severe service", since FL is hot as hell most of the time I changed it at 40K then again at 85K with a new filter as well, also cleaned up the pan too. Kinda stupid IMO, "hey, here's a $4,000 part that will fry out if it runs low on fluid but we will deprive you of any practical means to check the fluid level". My manual actually states "if you notice any leakage, bring it to a dealer", great, if someone is parking over sand or gravel and a seal starts leaking they are not going to notice any puddle and by the time the tranny starts slipping due to lack of fluid the clutch-pack is probably shot already..

 

[monkeydelmagico]

When the fluid starts to turn from pink to brown I get it changed. At 150k miles how could it hurt to have it changed?

 

[Mide]

I changed the CVT fluid on my Prius after I got it at around 30k. Big difference from the color of the new fluid. My recommendation would be to stick with the Manuf-brand stuff.

 

[Zenmervolt]

Sounds as if you have a sealed 'lifetime' trans. You shouldn't need to flush it or change fluid unless you've ever tripped the 'ATF Temp' warning.

I strongly disagree with this for anyone who intends to keep their car for a long time. "Lifetime" fluids are designed to last for the projected life of the car, which is generally 150,000 to 200,000 miles. I tend not to like anything longer than a 60,000 mile change interval for fluids, even on cars with "lifetime" lube.

ZV

 

[JCH13]

I strongly disagree with this for anyone who intends to keep their car for a long time. "Lifetime" fluids are designed to last for the projected life of the car, which is generally 150,000 to 200,000 miles. I tend not to like anything longer than a 60,000 mile change interval for fluids, even on cars with "lifetime" lube.

ZV

Heh, different perspectives I suppose. I put about 10k/yr on my DD, and 15-20 years of NE winters will rust nearly anything into oblivion, so I don't consider it a bad plan.

 

[JulesMaximus]

For what it's worth we just replaced my wife's IS250 because it needed a new transmission.

 

[Jimzz]

I strongly disagree with this for anyone who intends to keep their car for a long time. "Lifetime" fluids are designed to last for the projected life of the car, which is generally 150,000 to 200,000 miles. I tend not to like anything longer than a 60,000 mile change interval for fluids, even on cars with "lifetime" lube.

ZV

THIS


Mercedes, Volvo, GM, etc... all had their "life of the car..." trans fluid. Problem is many trans starting blowing up before 100k so they have all come back with change at XYZ time frame now even on older cars as well.

I hate that my wifes Cadillac does not have a dipstick. So to change the fluid you have to lift the car up and add fluid under the car while the car is running. Our old Mercedes had a dipstick tube but no dipstick. So you have to buy the dipstick but at least it was easy to change/fill.

But 30k on cars that are hard on their trans and 60k on ones that are easier.
For some reason the latest Toyotas I have worked on, 2010+, have all burned up their fluid much faster than before. Not sure if that's a new trans design or the fluid they use now?

 

[BUTCH1]

I assume this is an automatic?

I recently did the MT in my Honda, got the fluids from the dealer for about $15 and it was as simple as changing the engine oil except I needed a hose/funnel to get the fluid to the fill hole.

Honda is the only one I know of that features a drain plug on their automatic tranny pan's and still has a dipstick. One can buy aftermarket pans with drain plugs or remove the existing pan and a drain plug can be installed, just be careful the hardware won't contact anything inside when it's put back on the car and make ABSOLUTELY sure there are no metal shavings let over from when you drilled the hole to install the plug. I used brake cleaner to clean my pan when it was off then used a lint-free micro-fiber towel to dry it thoroughly when I was done.

 

[BlitzPuppet]

Honda is the only one I know of that features a drain plug on their automatic tranny pan's and still has a dipstick. One can buy aftermarket pans with drain plugs or remove the existing pan and a drain plug can be installed, just be careful the hardware won't contact anything inside when it's put back on the car and make ABSOLUTELY sure there are no metal shavings let over from when you drilled the hole to install the plug. I used brake cleaner to clean my pan when it was off then used a lint-free micro-fiber towel to dry it thoroughly when I was done.

My Altima's CVT has a dipstick tube hole with a cap, but no dipstick. It also has a drain plug, so that part is good at least.

You basically have to measure how much you take out and replace that same amount with new fluid. I'll probably aim at changing or at least checking the "deterioration level" when I hit 30K.

 

[Zargon]

Honda is the only one I know of that features a drain plug on their automatic tranny pan's and still has a dipstick. One can buy aftermarket pans with drain plugs or remove the existing pan and a drain plug can be installed, just be careful the hardware won't contact anything inside when it's put back on the car and make ABSOLUTELY sure there are no metal shavings let over from when you drilled the hole to install the plug. I used brake cleaner to clean my pan when it was off then used a lint-free micro-fiber towel to dry it thoroughly when I was done.

my astra has a drain plug, but the pan will dump ~2.5 qts of the 7 in it

so every other oil change I would just cycle through some atf

 

[Midwayman]

Mercedes, Volvo, GM, etc... all had their "life of the car..." trans fluid. Problem is many trans starting blowing up before 100k so they have all come back with change at XYZ time frame now even on older cars as well.

I know on the w204 MB car, or really anything with the 7G transmission they were having a lot of trouble with the transfer cases on 4matic equiped cars. They were burning up the ATF much quicker than expected and having to warranty a lot of transmission. Word has become to get them changed earlier than recommended. What is worse is that WIS instructs they to drain the TC as part of this and most dealers are lazy and only drain the trans. As a result about 3qt of dirty fluid gets left.

 

[SparkyJJO]

There's no dipstick on GM either and hasn't been since '98.

My old 98 GM had a dipstick, my current 99 and 02 GMs have dipsticks, and I know guys with 07+ GMs with dipsticks.

 

[thomsbrain]

I strongly disagree with this for anyone who intends to keep their car for a long time. "Lifetime" fluids are designed to last for the projected life of the car, which is generally 150,000 to 200,000 miles. I tend not to like anything longer than a 60,000 mile change interval for fluids, even on cars with "lifetime" lube.

ZV

Yeah, the ATF interval on my Accord V6 was 120,000 miles. The transmission died at half that mileage due to degraded fluid. Manufacturers can over-estimate the longevity of fluids and designs. In the case of the Accord, the actual appropriate interval is more like 12,000 miles, not 120,000. I wouldn't trust "lifetime" anything.

By changing ATF frequently, my second transmission has lasted 3X longer than the first, with no signs of any issues developing.

 

[Jimzz]

My old 98 GM had a dipstick, my current 99 and 02 GMs have dipsticks, and I know guys with 07+ GMs with dipsticks.

I know Cadillac has not had them in most of their cars for a while but most other GM cars I think still have dipsticks.
Maybe its a RWD vs FWD thing minus the trucks that need to check their fluid easier and change sooner?

Yeah, the ATF interval on my Accord V6 was 120,000 miles. The transmission died at half that mileage due to degraded fluid. Manufacturers can over-estimate the longevity of fluids and designs. In the case of the Accord, the actual appropriate interval is more like 12,000 miles, not 120,000. I wouldn't trust "lifetime" anything.

By changing ATF frequently, my second transmission has lasted 3X longer than the first, with no signs of any issues developing.

Yea I recommend doing a drain and fill on Hondas every 30k. Valvoline maxlife meets Honda spec and there are other fluids that meet Honda spec now.

 

[BUTCH1]

My old 98 GM had a dipstick, my current 99 and 02 GMs have dipsticks, and I know guys with 07+ GMs with dipsticks.

Are they trucks?. I know that in passenger cars they were gone in 97-98, I've heard that they were brought back in the Malibu in '08 but I'm not positive on that. Google "GM no transmission dipstick" and see for yourself.