Hi alll. I know there's lots of diff expertise in the S2K world, so I figured I'd ask this over here.

I just dropped the oil from my 2006 Lexus IS350's rear diff. Lexus specs a 75W85 GL5, which basically doesn't exist outside of a vat at the local Lexus dealer (i.e. they don't sell it in quarts) so I decided to replace with M1 75W90 GL5. I figure the viscosity difference is minimal.

Anyway, my question is this. When I pulled the drain plug, I saw what I initially thought was a LOT of wear material. What it turned out to be was some type of grease, and a good amount of it (pic below).

Does anyone know why all this grease would be put on the magnetic plug? I can't for the life of me come up with a reason. I ended up wiping it all down before I buttoned it back up and refilled.

 

Holy crap, are you sure that's not sludge? I don't know what that is, but why would Lexus cover the magnet with grease?

 

I'm no Lexus expert, but it appears to me that what you've shown is not just "grease". I believe it's the typical build up of metallic slurry that collects on all magnets of rear diff drain plugs. However, that is an EXTREME case and I don't think it's normal. Here is a pic of the typical slurry buildup on an S2000 drain plug:


If it were my car, I would run that new fluid for about another 500 miles and change it again.

 

Could be that it is a big buildup of slurry. It really did feel like grease, as opposed to the somewhat gritty feel you get from the slurry that comes off the S2K drain plug.

The oil itself looked fine... wasn't terribly dark or burnt. I suspect the IS might go through a severe break-in of the diff in much the same way the S2K does. I'll probably dump it again in 500-1000 miles and see what's stuck to the plug.

EDIT: I should have mentioned, the car has 5000 miles on it. I decided to dump it early to see what was what (Lexus specs checks at 15k miles and changes every 30k). Glad I did.

I should also mention: the drain plug magnet is almost an inch long. It's not just a little inboard magnet like the S2K's, but a "finger" that sticks out. So that buildup you see isn't solid, it's all around the magnet.

 

Then it's not as bad as it looks. Next time, clean it off so we can get an idea of how thick that layer of crud is.

 

Well, don't get me wrong. There's still a lot more buildup than I've ever seen come off my S2K plug. But no, it's not a solid chunk of crud.