mdrx350md

I realize that our transmission has a "lifetime" transmission oil but much like the other members of various toyota/lexus forums... I plan on doing a drain and fill every 30K for cheap insurance.

I was wondering if there is a DIY anyone has saved or a simple list of instructions I could follow. Actually, at a minimum a picture of the drain plug would help tremendously. It seems there is a drain plug that requires an allen wrench to loosen and then I could fill through the dipstick under the hood. I'm a weekend grease monkey and I've changed fluids on 02 Odyssey, 04 Accord cpe and 05 G35 cpe. But I've never worked on a Lexus/Toyota and would appreciate any guidance.

Thanks in advance,
Alex

joandjo

I'm also very interested to learn how to change the ATF on RX350.

I know there is a drain plug at the bottom of trans pan. It's 10mm hex bit - the usual Toyota trans style.

But to my understanding, there is no dipstick. Then, how do you refill the ATF?

mdrx350md

Thank you for the reply. I've posted on a few forums and you're the only person that has replied. The only "DIY" I've found was for a RX330 which did use an allen wrench to remove the drain plug.

I'm sure the drain and fill procedure is the same as the other manufacturers. I've done them on a 02 Odyssey, 04 Accord V6 and 05 G35 all in the past month and a few times previous to that.... no problems after 50K miles. Leave the car overnight. I do not do transmission oil changes when it's hot like you're suppose to because a tech told me that it can expand up to 20% when it's hot and I want to only put in the exact amount that came out. I unbolt the drain plug (much like your engine oil), let it come to a slow drip into a dry and sectioned 5 quart motor oil container jug, put on the plug with a new washer, measure the exact amount of transmission oil removed, place 3/8 plastic vinyl tubing (from home depot) fitted to a funnel connected to the quart transmission bottle into the transmission dipstick hole and let it drain into the transmission. It takes a while, as the fluid goes in at a very slow rate...3 minutes a quart.

Perhaps, no one responded because it's such an obvious question but I just wanted to make sure before I started the project. It's like an oil change but you fill through the dipstick hole. If you do it properly, the car is suppose to be warm and you have to measure the trans fluid around a certain temp (120? 149? degrees) and check the overfill... too much work, imo. I'll do it cold and put in the exact amount that came out. People at toyotanation said their Highlanders and other cars with the same engine and tranny combo came from the factory with 1/2 quart tranny fluid underfilled. I'm still going to put in the same amount. Hope this helps. Perhaps and expert or someone who's done it will chime in.

BTW, my 08 RX350 came with the dipstick.

Stormforge

no one has responded because you are the first person to ask this question (i think), and the fact the 3rd gen RX is so new. i can't help you as i'm no grease monkey. your best bet would be to ask your lexus mechanic for some tips. good luck

DNC

I completely agree with you on the insurance aspect. I would go a little further and say pay your dealership to do it as these transmissions are very susceptible to contamination that can often come by a DIY process; which can be worse than just leaving it sealed.

mdrx350md

It has 62k on it right now. I plan on using a new strip of plastic tubing every time so contamination is not an issue. It goes straight from the bottle into the inner side of the dipstick hole. I had some reservations about doing tranny drain and fills but it's basically the same thing as an oil change. I talked with a Honda Tech today (he happened to be in my office) and he said doing it cold should not be an issue but check it anyway while the car is running and after the engine has been running for a few minutes.

mdrx350md

BTW...the DIY I found was for a 300 not 300.

https://www.clublexus.com/forums/rx-...er-change.html

DNC

This is why I don't often reply to such postings. Most people have their minds made up no matter what you tell them. Yes, contamination is still an issue.
My dealership only has to hook up a machine and does not expose the sealed unit to the open air. Lexus tells you not to change it at all. Now you are talking to a Honda tech. Have at it. Be sure to change the air in your tires too.

LeoDLion

I have a 2010 RX 350. I look and look but I can not find the tranny dipstick. I believe it does not have any. I have a car without the tranny dipstick and to change the tranny oil, this is what I do.

First drain the tranny oil by removing the drain plug. Around the top but on the side of the transmission housing is a fill plug. Its usually a hex bolt. Sometimes this bolt is hard to remove. You may have to use a breaker bar or a torque wrench. This is the hole to use to put the tranny oil. The problem is you can not just pour it from the car because the hole is too small, its on the side and there is no space for the can.

To fill, get a 3-ft long plastic tubing that will fit the fill hole. At the other end, tape a funnel. I use duct tape. Starting from the engine compartment, snake the plastic tubing down into the fill hole and insert it in. Now you are ready to fill. Fill it until the transmission oil just comes out of the plug hole. When it does, you are done. Clean up the mess and bolt everything back. Save the tubing for next time.

Stormforge

if asking your lexus mechanic for tips is too difficult, just go buy the repair manual for your RX. it will tell you how to repair almost everything (including the proper way to replace the transmission oil).

mdrx350md

I had a patient that happened to be a Honda mechanic at the office and decided to ask him. He gave me some insight into performing maintenance on the "newer" Toyota vehicles. I'll call and ask a Toyota tech sometime before I do the tranny fluid unless someone else posts who've already done the procedure on the same engine/tranny combo.

A friend of the family is a Nissan Master Tech...you'd be surprised as to how much "contamination" leeway you have when you work on cars... even tranny flushes on the GTR. But are you stating that having open air contact can affect the performance of the transmission? I'm no MechE but doesn't that happen when you check your fluid level, even if you wipe off the excess? So unless you some insight in performing routine maintenance, don't compare what the service managers has said...they have to justify why you are charging 4 figure numbers on your credit card.

tromly

+1, can't believe how many people I talk to balk at spending $50 for a repair manual , yet spend 50k for their automobiles

LeoDLion

I make it a point to buy a service manual everytime I buy a new car. Sometimes I buy more than one. For my MX-5, I have three manuals.

DNC

I'm sorry but you are all over the lot on this subject. You start out admitting it's a sealed system and then ask for DIY instructions on changing the fluid, next you have come up with instructions for an RX330, then you say you don't follow manufacturer's instructions by changing it hot, and then you had a conversation with a Honda tech. You list in your posting you have a 2008 RX. If you don't have a 2010 RX you are even on the wrong forum.
Just go ahead and change your car's transmission fluid. That's what you want to do. You don't want our advice; you want a debate. I'm sure that Honda "tech", who you probably talked to for 5 minutes, knows more than any of us about a Lexus transmissions.

Stormforge

for my GS450h, i have 5 manuals!