Lexus Gs430 Atf Change?

[lovelexus]

Hi all newbie here. I've recently bought a 2004 GS430 SE. The car has just turned 100k and has a full Lexus dealer history.The car drives perfectly but I am wondering about doing an automatic transmission fluid change. The gearbox is smooth as butter but I cant see anything in the history to say it has been changed. Am I best to change it or leave it as is? Any replies would be greatly appreciated. I want the car to be spot on as I'm disabled and its my only way of getting around. Its just had a full service, ngk plugs, fuel filter, engine oil changed, k&n panel filter, new timing belt and water pump, new discs and pads all round, new tyres, cat back performance stainless steel exhaust and some paintwork rectification to get the car looking spot on and the alloys refurbed. As you can see I want the car to be perfect so I'm hoping for some advice from those more informed on the GS430 than myself.

[steve2006]

Hello and welcome to the LOC.

The general concensus of opinion for the Aisin transmissions seems to be a fluid change every 60,000 miles and the fluid and filter at double this.

I would have a look at the colour of the fluid which should be a dark cherry red colour, a brown colour would indicate a change is required.

For a full flush/replacement it takes around 20 litres of Toyota Type IV fluid.

It may be best to let Lexus do the job although it is DIYable.

[Steve]

local company will simply suck it out from the dip stick and replace it in 10 mins

[TigerFish]

local company will simply suck it out from the dip stick and replace it in 10 mins

The problem with that is it doesn't flush the fluid in the torque converter etc, only in the sump of the gearbox.

Much more efficient to drain the sump, refill and then flush out the internals by draining a litre out of the fluid cooler return pipe, refill a litre, run engine for a short period, and repeat until it flushes out clean from the pipe. Especially considering the Toyota type IV is not cheap, and you would want to keep wastage to a minimum.