Differential Oil Change

[james250]

I am going to attempt a differential oil change. According to the official workshop manual the IS250 takes 1.10 to 1.20 Litres. Everything seems rather straight forward except the car has to be level when filling. But one question, what if the car is not 100% level, then technically i wouldn't be able to get 1.10L in before it starts overflowing through the fill hole right? So technically if I manage to get anywhere between 1.10 to 1.20 Litres into it before it starts to overflow then it should mean it was level enough right?

[jumbojake]

I did mine a while ago . .was strightforward ... I needed to use a length of scafolding pipe as an extension to my socket as both the drain and fillplugs were extreemly tight.  I replaced the washers, couple of quid from lexus birmingham.

I have a slopped driveway, so was ok to get it level.   if isn't level, and  if you are relying on measuring the new oil, be concious you need to fully drain the old.

 

[james250]

1 minute ago, jumbojake said:

I did mine a while ago . .was strightforward ... I needed to use a length of scafolding pipe as an extension to my socket as both the drain and fillplugs were extreemly tight.  I replaces the washers, could of

I have a slopped driveway, so was ok to get it level.   if itn't not level, be concious that if you are relying on measuring the new oil, then you need to fully drain the old.

 

 

Thanks, i've ordered the two new washers for the drain and fill plugs. Which oil did you use?

My driveway is almost 98% level. if i park car on it and leave it on neutral it doesn't roll. That being said i dont think it is 100% level there must be some sort of slope. When I do my oil changes I just usually place concrete slabs under the wheels and that gives me enough clearance to get under the car. So technically if I put the same amount of concrete slabs on all 4 wheels it should be level and I might have enough clearance to do the differential oil change. But my concern was what if it isnt 100% level, As long as I leave the drain plug open and let it all drain out then technically as long as when I am refilling if it takes anywhere between the 1.1 and 1.2L before it starts overflowing then it means I have correct amount in there right? If it starts overflowing before 1.1L then it might mean it isnt full drained or the car isnt level and if it takes more than 1.2L then it might mean its also not level.

Is there a good way to check if the car is level? I could potentially run a long timber across from the slabs that will support back wheels to the slabs that will support the front wheels and then check the timber with a spirit level?

[james250]

Is differential oil same as manual transmission / gear oil? I am looking on Euro Car Parts and a lot of the oils that are 75W85 GL-5 are in the transmission oil category and are referred to as transmission / gear oil. 

[james250]

I've managed to source the correct 75w85 from Lexus they sell them in 1L bottles so had to buy 2 bottles. The second bottle I will use only 0.20L of it so I guess it can be used 5 times with a 1L bottle

[true blue]

Hi James ,I have done this job before ;2 tips I think will help  ,always loosen the fill plug first as if you take the drain plug out and then find you cannot release the fill plug ,you have a problem ! ; you will find the job much easier if you use a large oil syringe fitted with a short length of plastic ( cheap off E bay)

Dave

[james250]

2 hours ago, true blue said:

Hi James ,I have done this job before ;2 tips I think will help  ,always loosen the fill plug first as if you take the drain plug out and then find you cannot release the fill plug ,you have a problem ! ; you will find the job much easier if you use a large oil syringe fitted with a short length of plastic ( cheap off E bay)

Dave

 

Dave, thanks very much for the tips. Few questions for you if you don't mind seeing as you've done it before. I have one of those very large syringes I used for a clutch job on another car. Once i've drained the fluid and installed the new drain plug, do i just aspirate the gear fluid  into the syringe through a short tube and then press it into the fill plug and keep doing it like that bit by bit? What are the risks of getting air bubbles in there and how do you avoid that?

Also, this might seem like a silly question, but exactly where at the back is the differential? Want to see how high i need to lift depending on how deep i need to crawl in. Is it short crawl distance from the rear of the car or from the side?

[jumbojake]

Tho only risk with air bubbles is a (very) slightly error in the level, but 99% sure any small error would be negligible.  As soon as you drive the car, it will of course be churned up. The key thing with the siringe method is to have a wide enough pipe... mine was too thin and made it a very slow process.

 

As for the drain plugs, once you are under there is is obvious... agree with filler plug first ... and don't be alarmed if they are extremely tight ... sadly not enough room for an impact gun.

[true blue]

Hi James , as previously posted ,air bubbles will not be a problem , just suck up the new oil from the container and dispense through the filler hole . The diff casing with the plugs in is easy to see ,what I do to make life easier is jack up as high as I need ,put the approx amount of new oil in and then with a container underneath lower the car until level with the plug still out ,any excess will drain out giving the correct level . jack up again and refit filler plug .Please use axle stands when working under a vehicle NOT a jack on its own

Dave

[james250]

Found this video related to the new GS AWD but i assume the IS250 RWD rear change should be similar: