2006 Lexus IS 350 121k mi. It's new to me. Previous owner didn't recall any transmission fluid changes. Looking up service records at the Lexus website using the VIN didn't show any either.
According to the manual there's no fluid change required. According to the service advisor at my local dealer, a fluid change "may do more harm than good" at this mileage.
I'd like to inquire what all of your experiences have been in this regard. Any of you have 200k+miles on your car without ever having changed the fluid? Any of you done it and had a problem (or not)? This is my first experience having a vehicle that doesn't call for fluid changes although I've heard of them, particularly with CVT transmissions. Thank you.

 

It won't hurt to change it. But your gonna have to take a close look at the fluid just to make sure your not seeing a lot of metal shaving. Given the mileage you should be ok with drain and fill. I did my wife old is250 it had about 178k before i decided to do it first drain and fill. The new owner running at 200k with no issues. After i changed the fluid didn't really noticed a difference either.

 

Dealer is stuck in the past. This was somewhat true 20+ years ago when fluids turned to varnish. Technology has made that a thing of the past.

Change the fluid ASAP. There is currently a couple active threads on the DIY side of this topic.

 

Done numerous spill and fills on my 12' IS350c which had 121k on it when purchased, with no problems at all.

Also done it on my 03 Camry, 08 Sequoia and Ridgeline, and even in my 1975 Cadillac that probably didn't have the fluid changed in literal decades, and have not had a lick of trouble from any of them, or from any other car I've done it on in the past.

 

Additional transmission fluid service discussion located here;

#2IS Transmission Fluid Change DIY A760E RWD

https://www.clublexus.com/forums/is-...a760e-rwd.html

IS350 Trans Fluid Exchange

https://www.clublexus.com/forums/is-...-exchange.html

 

change the fluid asap, also, change the gasket, and filter while you're at it!

 

A piece of advice, if fluid was never changed, take it easy on the first drain and fill, meaning do not need to change the filter now. After driving around 1k miles, if there is no issues or problems, do another drain and fill and drive for another 1k. If its all good, you can drop the pan, replace the filter and do the drain and fill for the 3rd time. After that, do drain and fill every 15k-20k and your transmission should last a long time.

 

While the consensus is to change the fluid vs leaving the same fluid indefinitely, Jizz and Yamehoo you have opposing perspectives. I'd like to learn more about the rationale behind your recommendations if you don't mind.

 

I was a builder at a transmission shop for 6 years just about the time fluids made a breakthrough in performance.

I'm repeating myself but fluid technology from 70' & 80's would varnish. The varnish is a layer of material on surface that can be measured in depth. Adding new fluid that's high in detergent could devolve that varnish (where a seal or expansion slip ring is) creating both internal and external fluid leaks.

Newer fluids do not varnish and build layers. Thus there is zero reason to hesitate changing the fluid and filter. Period! Well unless it has varnished stinky yellow fluid from another Era, then caution should be used.

 

what i think yamehoo is trying to say is that introducing new fluids in one big wave (e.g. flush) can shock the system, but what 2013FSport clarified is that it's an older mindset and is not applicable for these transmissions.

over in the LS400 forum (older transmissions up to 2000), it is common to do the method outlined by yamehoo - to not do a full flush, but simply a slow progression of drain and fills; different than the IS being that it's newer.

 

Talking about yesterday again. Everything had a dipstick back in the day, and if you pulled the dipstick out and it was yellow (not pink, brown, or black), AND smelled of turpentine, AND had 175+miles, a fluid swap was a death nail.

Teflon hadn't really made its claim to fame in the 60's and 70's so all things prior had gapless metal slip rings to apply hydraulic pressure to other spinning components like clutch drums. When the metal was gone, varnish could fill some voids and a FUBAR trans could soldier on in a neglected state of maintenence.

As Teflon came into replace metal slip rings (reduced friction, wear, and heat) it needed its own expander device aka an oil resistant o-ring that slipped into a groove 1st and the solid Teflon ring went over it to form a slip ring that can withstand hydraulic pressure being applied to that same clutch drum. The rubber o-ring often work hardened/as did the teflon from the oil being used and internal leaks formed allowing clutch packs to slip and the trans would burn up.

Newer oils, with improved temperate ranges, and o-ring compatibility, as well as variants of the Teflon slip ring created durable long living transmission where everything mostly ran a long time (baring mechanical failure) and many applications went from death at 100,ooo to living past 200,000 mile mark or longer. Hint my 95 Camry 1MZ-FE had 350,000 miles on it. Never problem with me doing partial drain and fills from 145k when I grabbed it, gave to my son w/ 250k and was stolen with >350k by crackheads and totaled for having needles in it. I digress....

Hence there being so bloody many variants of transmission fluid as it's more about additive that support brand-x soft materials, so they don't degrade and fail like the first o-rings and Teflon materials of the late 70's, early 80's. By the early 90's, Toyota had it sorted pretty well, but the fluids still weren't up to 150,000 mile intervals like they are towards mid 2000.

If you're still reading, click the like button for the history lesson. Or if you were born in early 2000. 😜

 

Are you experiencing any issues with the trans currently? If not, I'd say you're a good candidate for a drain and fill. Some only pop into the forum and post when experiencing problems; and when it comes to the trans, in most cases it is too late at that point. Hopefully, you're just being proactive. In such case, go for it!