Time to change the fluids on my is300h - I have questions

NW_is300h · April 17, 2023

Hi everyone

Just signed up, i'm hoping you can all help me 🙂 I have a 2015 Lexus is300h that i've had a local back street garage have change the oil every 10k miles. The rest of my fluids.....well I've pretty much ignored them. The car has a 120k miles on it and nothing apart from oil has ever been changed so the plan is to either do it myself or get my backstreet garage to change the transmission, differential and brake fluid. Here goes:

1. Can the transmission fluid just be put in until it overflows? i've seen a couple of threads on here where people have measured the amount taken out and then put the exact same amount back in. In another thread the instructions (from a lexus workshop manual?) show you just fill it until it starts to flow out.

2. Differential oil is as simple as filling it until it overflows. Anything i should take into consideration or be aware of?

3. Are the gaskets/washers for transmission/differential and oil all one size?

4. Finally does anyone know the cheapest place I can get the genuine toyota transmission, differential oil and sump gaskets from?

I've had no issues with the car in my 4 years of ownership and i've put 90k miles on it.

Thanks for your help

Inazone · April 17, 2023

Following

J Henderson · April 17, 2023

You might consider also changing the coolant in the radiator and inverter.

Coolant Replacement

The differential crush washers are the same for both drain and fill plugs, so you need 2 of them - 12157-10010

Make sure you can crack the fill plug loose, before you attempt to drain the diff...

IS300FSPORT · April 17, 2023

For info I asked a similar question not too long ago user 'Notamech' replied with the following

All of these are from the official workshop manual and are for 2013-15

- Coolant - 8.2 litres of Toyota SLLC

- Engine oil drain and refill with oil filter 4.5 litres

- Brake fluid - Capacity not specified just says to fill to the max mark and use

SAE J1703 or FMVSS No. 116 DOT3

- Differential oil - 1.3-1.4 litres

- CVT transmission (L210 Hybrid transaxle) - 3.8 litres of Toyota ATF - WS

Since yours has passed the 100k mark 1st thing I would recommend doing is the coolant for the radiator & Inverter. Followed by differential fluid, brake fluid, CVT.

Also consider cleaning the main Hybrid Battery filter mesh & fan situated in the boot to prolong the Battery main traction Battery life. If its blocked up with dust you willl see better MPG & performance after a good clean up.

Check & replace the stretch belt since its past the 100k mark & if you see pink residue coolant near the waterpump (quite a few reports of early water pump failures) from owners on this forum. Its false economy to just replace the coolant if you have a failing water pump. Replace the waterpump at the same time replace the coolant recommended to only use Genuine Pink super long life coolant.

Look on Lexuspartsdirect website their prices are very good.

Order a 'complete service kit' & add diff fluid, CVT fluid, brake fluid etc

These cars are super easy to work on I recommend DIY if your out of warranty period & have safe access/tools to do the work.

NW_is300h · April 18, 2023

Thanks for the advice guys. I will put coolant on my list.

I'm still hoping i can get specific answers to my first and third questions in particular 🙂

IS300FSPORT · April 18, 2023

1 hour ago, NW_is300h said:

Thanks for the advice guys. I will put coolant on my list.

I'm still hoping i can get specific answers to my first and third questions in particular 🙂

Your probably going to struggle getting an answer alot of owners dont tend to DIY they go to the dealer for servicing to retain the manufacturer warranty.

Its safe to say if the transmissiin fluid has never been drained Lexus claims its a for life fluid never needs changing put in what comes out. Although there is a procedure to do it refer to the service manual, its as simple drain & refilll it put the plug back in, put the car in 'Maintenance mode' go through the gears to circulate the fluid & check the fluid & refill as necessary. I havent attempted a DIY yet so unable to guide you. There is a youtube video you can watch for reference.

& in regards to the gaskets/washers user J Henderson already answered if your looking for further clarity get in touch with Lexuspartsdirect via the contact form.