2004 430 with 88,000 miles. I bought it 2 years ago with 80,000 miles and don’t know the history of maintenance. Should I change the transmission fluid or not? I hear conflicting opinions. Not sure what to do??
Thanks for any guidance here.

 

What does the ATF on the dipstick look like?

 

Change it

 

When in doubt just do it, you will not be sorry,

 

Welcome to CL and Congrats on your first post!!

As already mentioned, and without knowing the history, I would change it as well.

If you don't want to pay for a CarFax -- You can always check the history on Lexus.com to see if it's been done by Lexus dealership. Put the VIN in your garage and make it your primary vehicle, then you can look up the maintenance history. It might not show, but at least you'd know the history up until the last entry. Sometimes Toyota entries show up on there as well.

I've heard you can't do this on your phone anymore, has to be on a pc or iPad, etc.

 

Remember, that fully 'changing' the ATF requires you to either mechanically flush it out of the entire system or do multiple drain-and-fill cycles to dilute the old into the new. What you get from the pan is only a fraction of what's in the system.

 

There's various schools of thought for transmission fluid. The LS430 forum is probably a better place to look at if you want more detail. Upper left search bar, go to advanced search, then select the LS430 and/or the SC430 sub-forums specifically (if you don't it'll search the whole Club Lexus forum). Particularly for the LS430 2001 - 03 model years as it's the same transmission in the 2001-05 SC430's. My summation of what I read is that for older transmissions DO NOT do a 100% fluid exchange as it will "shock" the system and possibly cause damage. General rule is to do a drain & fill. That would just be taking the ~4-5 quarts out of the transmission pan and then refilling it. It's generally always advised to drop the transmission pan and change the transmission filter and also a great time to clean off the transmission pan magnets.

If you are moderatly handy the overall process is more complicated than changing your engine oil. If you take the pan off (which I'd recommend) it can get messy. And transmissions are generally more particular about their fluid level. Idk what the process is for the 01-05 model years but I know for the 2006+ w/ the 6-speed you need to have the car running in Park at a specific fluid temperature then you let a level-drain plug open to set the fluid to the right level. If that sounds too difficult I would find a independent shop that specializes in Japanese vehicles, or better yet, Toyota + Lexus vehicles. I'd strongly suggest NOT to take this old of a car to the Lexus dealer. They'd probably do a fine job, but the master technicians that used to work on your 2004 SC430, when it was new, are no longer at the dealers and probably best found at indy shops instead. Just my 2 cents.

Generally we're all going to want you to maintain your vehicle so we have more pretty SC430's to look at on the road, so yes transmission fluid is a good fluid to service. As well as brake fluid, differential fluid, greasing door/convertible top seals, greasing the top mechanisms, and of course engine oil/ engine oil filter. But hey, if it drives great now why spend the $$$, just get in it a drive it!

 

OP: I went through the whole tranny fluid level setting thing when I owned my 2005Sc430 - 5 speed trans taking Toyota T IV fluid like yours. Everyone encouraging you to change the fluid seems to be right. A few things I learned in some cases the hard way.
1) Going for multiple drain refills is the conservative way to do it and avoids some of the force of compressed air etc flushing the old fluid out. Takes longer over several cycles but is gentler on the trans itself.
2) Don't use Toyota WS Fluid in the 2004 trans - has to be Toyota T IV fluid or equivalent. I used the Idemitsu equivalent and it was absolutely fine. Some have used the Aisin equivalent and that should be good too.
3) Level setting : Toyota wants you to have the car driven gently for about 5 mins. Then park on a level surface and then check the fluid level. That will tell you the most accurate reading. Cold readings right after you pour the fluid in may lead you to overfill - ask me how I know ...

 

Does this still work? I tried to create an account, but it wouldn't let me

 

Here is a super easy way to do it all at once
https://www.clublexus.com/forums/sc4...rain-plug.html

 

It wouldn't let you create an account? Hmmm, sometimes I get a weird error message, but just get out and go back in and it's fine -- sometimes it takes a few tries.

Last time I tried to look up a VIN, it did let me look up the maintenance, but I've heard you can't do it on your phone anymore. I never try on my phone. It's usually on my iPad. I will try again to see if it works when I get a chance at home and will update / Edit this post.

 

I just decided to make a new post. I saw a random SC for sale and just used that VIN and NOT mine.

It worked for me on my iPad, but it can be confusing. After adding the VIN in My Garage and making it the Primary Vehicle you want to:

1) Select Service Appointments & History — Then select PAST next to UPCOMING

and it will say THERE ARE NO PAST APPOINTMENTS TO DISPLAY below that





2) But if you keep scrolling down you’ll see SERVICE HISTORY and below that you’ll see the service date MM/DD/YYYY and (mileage) with + sign to the right





3) Click on the + sign and it will reveal the SERVICE DESCRIPTION and what was written.

This particular VIN had the first date out of order — never seen that before. So I clicked on the latest service date shown instead of the older one above it.





I hope this helps you @DshngDaryl


* EDIT: Just noticed the mileage discrepancy with the 2016 mileage entry being considerably higher than the 2020 mileage. Weird. They must've got the year wrong or somethin' fishy's goin' on... Oh well. I deleted it out of my garage already.

 

Just do the drain and fill with Toyota transmission fluid IV. It is the safest way for the trans and as easy as an oil change.

 

These assumptions need context. 1) 100% new ATF will not 'shock' the system, but the removal of sludge in an unmaintained transmission may reveal leaks or issues that were gummed up and invisible. 2) it would take 8-13 successive dilution drain and fills to equal one flush. That's a lot of waste and mess.

I don't power-flush my transmissions - I use a method like this one. I remove the output hose from the transmission cooler (in the radiator) and point it down into a graduated bucket. With the engine running, I fill fresh ATF into the fill tube as the car's own pump dumps the old fluid into the bucket (about 1qt every 20 seconds). When the amount in the bucket, the system capacity, and the new ATF are all equal amounts, the transmission is fully and gently flushed. That's admittedly not a method for everyone's skill level, but it works like a charm. Next best is the dilution drain and fill, but it will take up to 30qts to come close to fully flushed.

A single drain-and-fill renews only about 20% of the fluid. Practically useless.

 

@super77 -- We, admittedly, do NOT have that skill level, so if we schedule a drain and fill, how can we ask them to renew more than 20%?

Would it be better to go thru the dealership's service dept, or a Japanese Specialty Mechanic that's done our OCI and recommended ATF be changed?

We can provide the Toyota ATF Type T-IV for them to use and just charge us labor -- so roughly how many quarts should we buy?

Thanks much for your help.