I just completed this DIY my '03 with 218k miles.
Thank you to the OP for the great write up!
If I had to guess per the looks of my oil it had never been changed. I've only driven a couple of miles, so I cannot comment on any changes in how it feels.

 

Moderators,

I meant to post this under the differential fluid change DIY. Feel free to move my post there.

 

I guess it's possible to trash an LS differential. In the video the oil drained very slowly. It looked like glue. No mention of how many miles.

 

I had my indie do it, he told me of course you can DIY something like this (I used to have to top off my Volvo since it was leaking) just that you need to have the vehicle level. He suggested leaving it on the ground and running a long tube to it etc. But since he was doing the tranny drain/fills 2&3 I just gave him 2 containers of M1 and the crush washers (have 8 left) and let him keep the rest (what am I gonna do with it anyway it's like a tip).

Anyway I never gave the rear diff any thought until I heard howling (which in the end were those dag Michelin Xice 3 snows). It's a very expensive piece of hardware, and even to do the carrier bearing the exhaust would have to come out...so this is really the ounce of prevention type of deal....nice work!

 

I have drained and filled my differential twice over 98k miles. Once around 30k and the fluid was very dark and looked like it needed to be replaced, second time around 85k and the diff fluid was still pretty clear and in good shape. I used a high quality Castrol full synthetic 75W-90 both times.

I'm thinking it is likely a good idea to get the factory fill and initial wear particles out of the diff relatively early (maybe 30-50K time frame?) but going forward, (after first d&f) maybe one d&f on the diff every 75-80k miles is plenty. It is a pretty easy job, just make sure you have one of those manual hand pump with tubing that fits correctly onto the two quarts of diffy fluid you will put back in. And make sure you verify that you can actually reach and loosen the upper fill plug before you loosen the drain plug.

 

I bought two new crush washers at my local Toyota dealer for $2 each. I haven't noticed any change in the drive, but I didn't expect to either. I think this is definitely something most people don't think of doing until it may be too late. I appreciate this very helpful forum!

 

It was not too bad of a DIY. I raised my car with a 4x4 under each tire to help me reach the plugs. I used Mobil 1 synthetic 75W-90 and I did loosen the fill plug first as well! I bought the manual hand pump at Harbor Freight and of course it did not fit the bottle. I had to Macgyver it a bit by cutting off the top.

I assumed it had never been changed because the oil did look pretty dark, but I guess you never know. There was no mention of it on the Lexus driver site. Regardless, it's done now!

 

I had also bought a pump, it was for a gallon not a quart. But I was also thinking, I don't think the gear oil is a normal quart opening, it's smaller, so what is the perfect pump to use? Unless one just uses a generic pump that you can get for like $6 less 20% at HFT, I have used that to extract coolant from a reservoir.....they cost double that on amazon....but I could envision spilling etc...

 

this is pretty important I've found. In some cases I've tried to re-use an existing washer and just tighten the thing down good. Doesn't stop the very slight weepage however.
Save yourself the extra hassle and just get the new crush washers to begin with.

 

I bought a 10 pack, not sure when the other 8 will ever come in handy (85k from now?), was $8. If you buy a BMW oil filter, it always comes with a rubber gasket, a rubber washer, and a copper crush washer, people have tried to save these parts and reuse old, only to be faced with a leak. I kinda get it, why waste something if you think it's still good....since the drain plug washer on the LS430 is metal, I don't feel that one has to be changed every time (it doesn't crush), though I do have a 10 pack of those too that cost $6.xx.....guess common sense should prevail and it does say to replace them on the rear diff...

 

I will admit that I typically reuse washers. Having said that, I'm currently doing a 3X D&F of my transmission fluid and I have been reusing that washer. I will do the third D&F next weekend most likely. Do you happen to have a spare washer laying around for the transmission plug? I'll gladly Paypal you the $.50 postage.