IS350atWOT

iTrader: (1)

I am about to hit 15,000 miles and I want to do the recommended rear-differential oil drain and refill. I want to use a good synthetic gear oil. I was wondering what brand/weight people on here are using on their F.

MINO

iTrader: (4)

Redline GL-5 75w-85.
It's cheaper than the OE oil.

Joe Z

iTrader: (10)

Book/PDF shows 1st scheduled service for IS-F Torsen Differential (2010-2011) at 60,000 miles... See here 2011 Lexus IS-F Service Intervals

- Any sooner is really a waste, in my own honest opinion.

I would say you can easily wait till 30,000 miles..
Back in the day, I used synthetic Royal Purple Max Gear 75w90 on my IS300 w/Torsen LSD, every 30k miles

It was always clean when I drained and refilled...

I have to look at the manual and see what is says for the 2008-2009 IS-F

Joe Z

itsmike177

iTrader: (3)

Changed mine at 30,000 miles with Royal Purple gear oil (2008 MY.) The old fluid still was golden in color, not dark, so I believe it was still good for another 30k. The magnetic drain plug had a very thin layer of metal shavings too, so minimal wear overall.

But the 2008 is an open diff, 2010's+ with Torsen will probably show more "wear" in the rear diff fluid.

IS350atWOT

iTrader: (1)

Oh man, I totally missed that my 2010 F was on a different differential oil change schedule than my previously owned 2009 IS-350. Thanks Joe! And thanks to everyone else too. When I do change it at 60,000, I'll have some good suggestions from you. This forum is great! Thanks!

trackdood

iTrader: (1)

Changed mine with os giken oil and the weight I have to check but changed at 34k with the diff went in.

Joe Z

iTrader: (10)

No problem... The IS350 doesn't even show for service due at any mileage

But, I did my own IS350 at 30k and it was very clean... LoL
(not a true LSD in it anyways)

Dealerships will sell this service interval for every 15k miles...

Joe Z

mdsbrain

iTrader: (9)

2008-09 IS-F says to change the Diff fluid every 30K.

lobuxracer

iTrader: (2)

Please locate where it says this. I was unable to find it. At all - even out to 150k miles.

mdsbrain

iTrader: (9)

Just going by what we were told locally. That what was is in that book is the minimum work to do on the car.
Even though maybe see that policy as a way to get more $ out of us.

Joe Z

iTrader: (10)

^^ Correct... !!!

Yeah unfortunately, the 08-09 falls under the “Inspect Only” criteria
(Just like all other regular 2IS’s that are RWD)…

I wonder if that’s because the Lexus Official recommendation is: it doesn’t need changing because there is no Torsen or true LSD unit in it..?!
or if the oil looks bad, then time to change the oil.

What should be the rule of thumb on this Lance?? Don’t change at all or change every Xx,xxxx miles ?
And I’m not concerned what the dealership service writer’s recommend .. LoL

Plus, I'm not going to inspect the diff oil every year..

But, I don't mine changing it every 30k miles per se.


Joe Z

lobuxracer

iTrader: (2)

The Supra with the Torsen diff had a 20k OCI. An open diff has a lot less wear possibility. BTW, you NEVER put additives in a diff with a Torsen, only on a clutch type LSD. As long as the oil meets GL-5, you're golden, however, it is possible to get oils which reduce gear noise and you'll likely pay more for them. From a wear perspective, the smallest of your worries is the quality of the oil. Under normal street duty, a properly set up differential will last 500k with almost zero maintenance - just be sure to top it off from time to time because there is a breather on the diff and the oil will evaporate over time. The only real concern with any diff is the hypoid gear set and the pinion bearing because they are heavily loaded. Everything else is ball bearing cassettes and relatively lightly loaded.

If it is poorly assembled and the tooth contact pattern is bad, there is no oil made to reduce the pain and suffering this will cause. The factory does a reasonable job of this, so the factory build with the factory oil can last a ridiculously long time for an open diff.

Joe Z

iTrader: (10)

^^ Great Info right there!!!!

So basically, if you never install a true LSD, your going to leave your diff oil alone... ?!

Thank You
Joe Z

lobuxracer

iTrader: (2)

Me? Probably will change at 50k intervals. I drive on the track. It's a bit more arduous than street duty.

Joe Z

iTrader: (10)

Thanks Again!!