JeffKeryk

I am planning on servicing the differential on our 2013 GS350 F Sport that just hit 60K.
I do not want to use the Toyota factory fluid....

I am considering Mobil1 75w90 Synthetic LS or AMSOIL 75w90 Synthetic.
I believe 2 quarts should do the trick.

Any real world guidance?
Thanks in advance.
FYI, I will service the transmission with Idemitsu ATF; it's good stuff.

AJLex19

My mechanic used 75w-90 Mobil 1 synthetic GL-5 gear oil for the rear. Here's a great DIY from one of our forum members: https://www.clublexus.com/forums/gs-...id-change.html

bclexus

I'm guessing you think the Toyota/Lexus engineers don't know what they're doing...

While your non-Toyota lubrication choices for the differential should be fine, I'd be very wary of using anything other than Toyota WS automatic transmission fluid in the transmission. Transmissions cans be very finicky about even a slight change in the fluid used...and Toyota transmissions are no exception.

er34

I used Shell S6 synthetic 75w90 for both front and rear diff. You'll need about 1.5quarts for the rear and about a quart for the front.

JeffKeryk

You guessed wrong. I have been buying Toyota cars and trucks since the 1980's. All have been great vehicles.

Longevite1

Used Redline 75-85.

bclexus

Of course I was referring to what fluids the Toyota engineers use, particularly for the automatic transmission.

richard203

iTrader: (1)

I used mobile 1 for my diff fluid and Toyota WS for tranny fluid

terrryz

What's wrong with Lexus factory transmission fluid?

JeffKeryk

There is nothing wrong with the factory fluids.
I don't know much about the differential fluid, except it is kinda pricey.
Mobil1 75w90 LS is synthetic and is about $15 a quart. This is what I will probably use.
WS ATF is not synthetic; Idemitsu has a WS replacement that is synthetic.
They worked with Toyota to develop the blend.
https://www.idemitsulubricants.com/i...tf/type-tls-lv

Personally, I do not believe in lifetime fluids, but that's just me.
We also have a 2006 Acura TSX with 185K miles; a wonderful car.
I serviced it regularly with Honda DW-1 (synthetic) since new.
Last time I used the Idemitsu equivalent and the transmission was simply wonderful.
Dang thing pulled better off the line better; was better all around.

Finally, this thread was not about dissing Toyota fluids.
I specifically asked for real world use of differential fluids other than factory 75w85 fluid.
Thanks to all who posted.

So, I do not believe there is anything wrong with the factory fluids.
I do believe there are better fluids out there.

timmy0tool

iTrader: (7)

+1 for factory fluids, they are well designed for their purpose, though gear oil difference will be negligible if you use aftermarket.

i'm also under the opinion to only use Toyota ATF in the transmission, as pointed out they are very sensitive and specific to fluid types.
this has always been the case with older lexus cars and more so with the newer!

terrryz

For me the ATF is definitely one of those things that fall into the ain't-broke-don't-fix category. Chances are the transmission would work just as fine with other fluids, but I don't see the point of taking the risk unless there's a clear upside.

It's just too complicated a matter for most people to understand correctly. Unless I work at Toyota/Lexus as a ATF tester and know for sure there's an better alternative that's not used because of cost, I wouldn't deviate from the factory recommendation. The factory fluid should be the right compromise among performance, longevity, noise, and cost for most people.

Trianon

Today I called Lexus parts in Toronto to find out what gear oil are they using for rear differintial and front transfer case.
The answer was - Mobil 1 is making for us 75W90, despite the owners manual recommends 75W85

charley95

Here we go again.

JeffKeryk

I ended up with Redline 75w85.