Autobox oil change

[is200 Newbie]

Had a partial gearbox oil change today.

Cant be done in a one step process so its being done over 3 months or when I can fit the time in to get it done.

Asked for a sample of oil from the box to compare to the new oil.

Car is almost on 101,000 miles and I have no idea if this change has been made at any point in the past (no history either). Sample used oil was in a small jar initially but I put them both into plastic bags to compare better and to see if I could feel any contamination which I couldn't.

The smell on the old oil was bad - smelt like old engine oil (a bit burnt). The oil in the picture (coloured red) is the new - the black oil is out of the box. This may very well be a lifetime oil in the box but I would really like to question what the expected lifetime of the car is from the manufacturer as this used oil is very bad and needs changing and at a sooner interval than 100k although this must depend on use

The gearbox operation has noticeably changed - smoother gear changes in auto mode but stll a bit noticeable between changes but I expect that to get better over time when the further oil changes have been completed. Will update when the 3rd change has been done. Picture below

[Linas.P]

That is an impressive visual comparison. 

In terms of expected lifetime - I doubt Lexus expects you to drive over 200k and mainstream support is planned for ~ 60-100k. If you choose to change the oil I am sure this box can last even longer probably 300k is not an issue. As well that is good point - there is no such thing as auto-box oil change, but rather as you have described "top-up" or "refresh", where they add like 0.5-1l of oil at the same time draining the same amount of old one.

[ColinBarber]

1 hour ago, Linas.P said:

there is no such thing as auto-box oil change, but rather as you have described "top-up" or "refresh", where they add like 0.5-1l of oil at the same time draining the same amount of old one.

Flushing machines exist although reports suggest these can cause problems by stirring up debris on older vehicles which can clog the valve chamber. Or you can do it manually, drain the pan and refill, pull a line off the cooler, pump out 0.5 l then turn off the engine, add in 0.5l fresh into the box, repeat pump out/replace until the fluid coming out turns from dark to light red.

Best not to let it get in too bad a state in the first place, do a pan drill/refill every couple of years once past 60k miles.

[Linas.P]

I was referring to mainstream support manual.... obviously oil can be changed, but as you pointed out yourself it might not be a good thing.

[Verbout]

Interesting "How to" here:

 

[is200 Newbie]

46 minutes ago, Verbout said:

Interesting "How to" here:

Makes sense and looks like a very easy process (just like bleeding your brakes !!)

I never understood why it was claimed that oil changes could not be done on this box - glad I have had it done though but may be of use if the process in the vid can be done on these cars as it could be easier than people think and its definitely a job that needs to be done on a regular interval (100k is too long..)

The auto boxes on ours are cooled and the temp is regulated through a sensor mounted on the box itself - the change needs to be done at temp which is one point that was not mentioned in the vid

 

[johnatg]

The job is rather easier on the IS250 than on that pickup because we have a drain plug. You can only drain a litre or so through it though - the whole tranny takes 7.2 litres. If you want to drain more you need to go further and remove the oil pan and valve body, but even then you only get 2.2 litres out. Next stage is remove the torque converter - then you get 3.7 litres out - still not much more then half, and do you really want to go there?

The final adjustment of the oil level needs to be done with the oil between 30 and 49 deg C.

The main problem is access - you need to be able to get the car high enough to do the job and it needs to be level. So a whole lot of jacking and 4 axle stands required. Or a lot easier with a lift.

[messi]

I remember I wanted to get the gearbox oil changed at Lexus dealers and they said it would be like a top up as you should never drain the whole lot at is can cause damage to the torque converter if that makes any sense.

[shanra]

I think this explains a lot.