How often should this oil be changed ?
The OEM oil lasted 14 years and 150,000 miles.
Did I change it too soon ?

 

No I thought it was every 90k. I gave some Mobil 1 gear oil to the indie as I heard vehicle should be level when filling.

Have not done my wife's yet but I was planning to do rear diff and transfer case (AWD), and what I've heard is to expect the rear diff to be black with metal shavings stuck to the plug, and for the transfer case to be clear, at 100k.

 

In the official Lexus 2002 Canadian all-models Maintenance Guide, rear diff oil change spec is every 32,000km, so at 160,000km, 192, 224, etc.

I've since lost this PDF guide and it's tough to search these forums for it (not sure if I got it from here originally, either way it was 5-10 years ago), so if anyone still has it, please repost, thanks.

 

The proper viscosity and correct level are prob more important than the age of the fluid.
Lexus service intervals suggest inspection at 30k, 60k, 90k, 120k.......................... and some odd intervals thrown into the mix like 75k and 105k.
It does not, however, say "replace" at any interval so...........?
I'd like to think yours was due at 150. I'm sure your diff thanks you.

Edit: Stan I only have the 2005 document, I'm attaching the PDF

 

Interesting. I am sure it didn't "need" to be changed. I just like bragging about how clean the fluids are on my Lexus , lol

 

Do you think anyone on the planet changes their differential oil every 32,000 kilometers ? I really doubt it.

 

Maybe some rich off-roaders do with their six figure vehicles. For real. But in this car, no.

 

You should change it every 60,000 miles, 30,000 if your car is driven in snow just my personal opinion. I say 30,000 because of the oil heating up, cooling down, temp extremes, getting moisture in it and just more usage due to snow.

 

I have a Ford F250 4X4 and installed a locker in the rear differential at 70 K miles. Used a full synthetic 90 weight I bought at K Mart to refill it. For some reason I had to drain it at 100 K miles. The gear oil was as clean as when I originally put it in. Put the same oil back in.

Ran across a really good article recently about wear on ring and pinion gears. They basically said that once the gears wear in, which happens in a few thousand miles. They are set for good. That is unless something breaks.

I could see a drain and fill at 150 K miles. Use a full synthetic and then leave it alone. By the way, I've used that K Mart 90 weight (I think it is distributed by Valvoline) and have seen an increase of 1/4 mile per gallon in a truck that normally gets 10 MPG.