jdanielca

So we constantly hear horror stories about flushing the transmission. Is drain and fill even a good idea? Or should we just leave it alone? I have about 88-89K miles... what you guys think? If a drain and fill is a good idea.. then what procedure should I follow?

rick3242

I have a 2010 Toyota Tundra that I put 100K miles on last year. Had the fluid flushed and shortly thereafter have had very minor trans issues. The symptom is very infrequent and very minimal. None the less I do have issues. The tech told me that when they flush the tranny that sometimes it stirs up minute shavings / metal particles that will intermittently get caught in the fins and eventually should settle down. None the less I will never flush a tranny again. My LS460 has about 60K and I will not touch, flush or drain-refill the tranny unless I have some sort of tranny issue that needs addressing. If it is working fine I am going to leave it alone.

texas008

just fyi, I've done several transmission services on my 2009 LS460:
replace filter, and fill @ 70k miles
and then drain & fill every year.
Transmission feels much smoother, with no more hesitation in acceleration. and gas milage improved a little as well.

mckellyb

See this thread for a complete fluid exchange at one time:

Transmission fluid EXCHANGE, not flush, in your garage

jdanielca

thanks but I am not doing it myself. I do not have anywhere to do this.

writes123

My LS600 got a 12 qt transmission service by independent Lexus mechanics at 98k/5 yrs. Judging by the amount, this was more than a simple drain and fill down multiple times. Most likely a fluid exchange. Granted this is a CVT not the 8 speed one in 460's, I think it's prudent to remember that ATF's worst enemy is temperature and it ought to be replaced periodically as a part of preventive maintenance. No problems from shifting and I did a similar ATF fluid exchange on my 430 at 128k miles and had no issues with the transmission after as well. A simple drain and fill is very safe to perform so long as proper fluid levels are kept.

Nospinzone

JLAWS

I wanted to "treat" my 08 LS460 for being such a well behaved vehicle with a drain and fill from a Lexus Dealership. I may have to think about it more. The service is about $300. It drives very smooth now at 95K miles.

stasek

mckellyb

Transmission oil has a lifespan, just like motor oil and differential oil.

Motor oil we're all familiar with...three months, three thousand miles...yada, yada, yada. That was fine for 1978, but there's been 40 years of petroleum lubricant tech heaped upon motor oils.

I'd say the bare minimum, now, is 12 months/5K miles, and that's if you "Aunt Minne" the car in how you commute. See the attached Popular Mechanics article...then look at the date. Yeah, this has been around a while.

Using Mobil 1, the regular M1, not "high mileage" or "extended interval" stuff, and a Wix filter in my '08 LS 460 L (which holds 9.1 quarts, we'll discuss that, later), I'm at 15K mile changes, now, and going to see if 20K is in the realm of possibility because, according to oil analysis, the 15K mile stuff I removed last time was still good for a few thousand...at least.

I think the key to longer oil change intervals is a large sump capacity. 4.6L engine and 9 quarts of oil. That's double what automakers used to do with sump size.

Mercedes did this decades ago, and not just with the diesels. My '89 4.2L S-class held 8 quarts. Even the I-6 '95 E320 I had also held 8 quarts. This is for a 3.2L, low-stress inline six cylinder engine.

Please note, Mercedes engines tend to last a long, long time. A guy I work with, in fact, has a '96 E320, has 320K miles on it, at least. It's a little beat up, but it runs just fine. No leaks, doesn't burn.

This said, we can check engine oil, regularly, and see it turning color over time as it keeps contaminates in suspension, like it's supposed to. This is why there is a time limit on oil...eventually, the oil can't hold those contaminants, and they tend to be acidic. Once they're free-roaming, then can, in theory, etch the metal in your engine.

Differential oil, everyone ignores. I'm guilty of it. My LS has the OEM oil in it, as does my '98 Grand Cherokee 5.9L (in both diffs and the T-case). However, they won't by the end of the year, as they'll have fresh Mobil 1 axle 'grease' in the pumpkins. Well, the Jeep might get regular stuff, as I need to work on the rear axle and the transfer case, anyway. Once I change the LS, I'm not touching it, again.

Transmission oil, though, is a strange animal, as it is rather heat-sensitive, and most vehicles don't have any indication of transmission temperature. Temps over 220F break down transmission oil in a hurry. Remember, it's only about 2.5-5 weight oil. Once the oil molecules start to break down, the oil can no longer lubricate the way it should, and it snowballs in a hurry. There are no combustion byproducts to hold in suspension, but it 'wears out' or gets 'used up' just like motor oil does.

Just because you've never changed transmission oil and have never had a problem, don't assume you're doing it correctly...you're just lucky. Transmissions wear out, sure, and automatics consume clutch material, just like manuals, but because the clutches in an automatic are oil-bath clutches, having burned oil is very, very bad for the friction material and can cause the clutches to slip. Once this starts, your transmission is doomed.

Kennyr44

rick3242

What do you mean when you say you drained and filled it three times?

texas008

that's why I try diy the services as much as possible..

texas008

perform 3 drain & fill, with certain amount of driving in between.

2013lx570

Did you ask your dealership for a refund since service was not performed? The drain fill 3 times is what honda tsb recommends for fluid changes.