Great write up!!!

 

Done. Thanks for the write-up and pictures!

Javier

 

I understand how car enthusiasts like to change fluids more often than necessary, but I still think there is reason to consider the down sides too. You should consider that differential oil doesn't have nearly the abuse that engine oil does. It doesn't get all the contamination from combustion, dirt, and moisture that engine oil does, and I really doubt it reaches anywhere close to the same temperatures on the street. I don't see how any contaminants would enter the oil other than steel that is worn off the gear teeth, and that is collected by the magnetic drain plug. To me, I'd rather keep the factory (warranteed) oil in there until I really think it needs to be changed. For you guys that are using aftermarket gear oils that don't match the OEM spec, you may be opening yourselves up to a denied warranty claim if your diff ever fails.

 

^I couldn't agree more Greg.

Javier

 

Greg or Javy...

What kind of gear oil comes in the IS350 from the factory?? and whats the actual service life of this said oil?

We know it takes 1.42 qts ......

Thanks
Joe Z

 

I haven't looked for the OEM spec, but Janizary said above ...

I suspect Lexus used a high grade oil from the factory.

 

^ I don't have my manual handy...

But with my Torsen LSD in my IS300, the manual suggested inspection every 15k miles and drain / refill every 30k miles (i think)..

It called for basic 80/90 gear oil with additional few ounces of LSD Additive when applicable...

After I went to full systhetic, I drain & refilled every 30k miles.. Again this was my IS300.. I know they are two different cars, but a differential is a differential..

Moving gears and parts which makes the wheels go round & round.. LoL..

 

After doing my own ring and pinion swap in my S2000's Torsen diff, I can tell you that there are a lot more moving parts in a Torsen diff than there are in an open diff.

 

If you change your diff oil to synthetic it should be good for the life of the vehicle, Don't waste your time and money. Also, don't change the oil when the diff is hot. This may be the reason you may need a breaker bar. The plugs will losen much easier when ambient temperature. A nice summer day is good enough to drain easily.

This is the only thing I will use!

http://www.amsoil.com/storefront/svg.aspx

Koz

 

For those of you that are hell-bent on changing your diff fluid, I would seriously consider using Lubrication Engineer's 1602, 1603, or 1604 (depending on your climate). It isn't marketed to the public, but it should be possible to find somewhere on the internets. This stuff was friggin' awesome in my S2000. After installing 4.77 gears, my diff was much noisier than stock with Mobil 1 75W-90, but the LE-1604 (aka LE-607) made it really quiet again.

 

Discord. I love discord.

It was not my intent to tell people 'Go change your diff fluid', just 'how to' if you are so inclined. But discord is good nonetheless.

 

To save yourself grief use this!

http://www.amsoil.com/storefront/g2039.aspx

 

^^ So what do you guys (Gernby & Koz) think about Royal Purple???

 

I haven't ever used Royal Purple, but I also haven't ever heard anything particularly great about it. I've always suspected it was just another Snake Oil like Slick 50.

 

Royal Purple makes high quality products. Right up there with the best!

Koz