OkieLex430

HI all! I recently bought a 2001 LS 430 and want to change the rear diff fluid ( I am a bit of a maintenance junky). The owners manual says to use 90 W GL-5 lube. Apparently from what I have been reading in the forum, I don't need anything with a limited slip or friction modifier additive, since it is a standard non-limited slip rear diff. Is this correct? Just plain old 90 W Gl-5 gear lube? Valvoline makes a 80-90 W that the manual says can be used in cold climates and since they sell that locally that should be a good choice. Am I tracking correctly?

LS430inDE.

What a coincidence! Today I bought some gear oil for my 2005. I purchased WALMART'S house brand 75W-90! It's only $5.17, and I've read it has better cold and warm weather characteristics than some of the big names! (I bought 2 1-quart bottles) Kind of weird they call it 'syn blend' yet the description says 100% synthetic and other parts of the description says conventional oils and synthetic. I honestly don't care, and neither will my LS that has 150k miles.

I will also admit I didn't read my owner's manual to view the proper weight of the oil. I searched here on the forum and nearly everyone talks about 75W-90 in the differential. Here's the link... https://www.walmart.com/ip/Super-Tec...Quart/16795248

Free shipping for $35+ orders too. Guess what else I bought? Several gallons of the Valvoline Asian (pink) coolant that's supposed to be rated for use in Toyota/Lexus. Walmart vs Amazon?......I've used Walmart for my last 2 online purchases. Did I mention free shipping for $35+ orders? No "prime" membership needed!!!!

Jabberwock

I have used Castrol full syn 75w-90 a couple of times with no issues.

05ls430518

iTrader: (1)

My personal preference is mobile1 75w-90 its full synthetic i also use mobile1 in everything though.

Johnhav430

My understanding is the rear diff has a label on it to use synthetic 75w90, so I went with Mobil 1 as it was $1 cheaper at about $11, and more than 1 bottle is needed unfortunately. I gave it to the indie and let him keep what was left in the 2nd bottle (the idea is we're 90k away from needing it). Bought the crush washer as well and he didn't charge me as he was already doing the tranny drain/fill. I know it's not rocket science but again supposed to be level when doing the job (with my Volvo I didn't worry/bother, just jacked it up)....

edit here it is, also I got the wrong pump

https://www.clublexus.com/forums/ls-...ill-ls430.html

Johnhav430

I know that Mobil 1 often gets a bad rap, but even if it's an endorsement, how come when you lift the hood of at least a 2015 911 Turbo S, it has a Mobil 1 sticker on it, and same for Corvette? It can't be that bad of an oil is what I think. And I have no clue why it lost the BMW LL-01 designation at the end of 2015, I think $$$$. On the crankcase oil I just go for the rebate, which usually means 2 jugs of M1, and 4 jugs of Penzoil Plat.....each year...

2KHarrier

Yeah, I used Mobil 1 75/90 last year when I swapped out the diff fluid. It's just good stuff..

05ls430518

iTrader: (1)

agreed man if people in corvette forums are using it on a 1000 horsepower turbocharged car then its more than good enough for my slow car lol

LS430inDE.

I guess we're tracking away from the OP's question. (What gear oil does an 01 take in the rear diff?) If the book says 90, you will be fine with a 75W-90. The GL-4 vs GL-5 rating apparently is pretty important to follow, from what I've read, so ensure you use GL-5.

Johnhav430

the answer is synthetic only, 75W90, API GL-5. There is a label as well on the diff to remind anyone working on it....

rkw77080

Apparently, the 2001 LS430 rear-end comes in 2 flavors - with or without a "Synthetic Oil Information Label". The Owner's manual has this to say...

Johnhav430

Very interesting, are they the same differentials, or dissimilar? Did 2002 go to all synthetic? Enquiring minds want to know....

edit ps I've been told a 75W90 is the equivalent of a 10W40 as the rear diff does not reach temps that a motor would. But it would seem that a straight 90 would be for most cars without a label, because the deciding factor is if you'd go below 0F. It would seem a waste to accomodate 0F if one never sees that. We got to -2F over the last week and a half, but that is rare. Rather just have 75W90 but seems it's wrong without the label....now it seems essential to look for the label, to make the correct decision...

05ls430518

iTrader: (1)

If i had to guess 01-03 is non synthetic and 04-06 is synthetic when they changed the transmission from 5spd to 6 spd, i am guessing on this so keep that in mind. There is no ls430 that comes stock with an lsd so, may if in another country there was a tow package or something and tbats what takes the synthetic? ......just another guess