well i change my engine oil every 1000 miles until i go synthetic which ill change every 3000 miles.
at 6600 i changed my transmission and differential since im going FI very soon.

 

just a note you might want to make sure you have an extra fill and drain bolt just in case you strip them, I am currently waiting for my new ones to come in (5 bucks or something close for them)
Jeremiah
Also I do mine every 15K like the book says

 

Does a differential need to break-in for a certain amount of time before you put in synthetic gear oil, like our S2000 engine, or is it OK to switch to synthetic at any time?

 

You can switch over anytime - I like to do it within 500 miles to get the metal particles out - ring and pinion are hardened metals, but they do need to break in, but there is no issue with too much lubricity in the diff as there is for the engine and tranny.

 

[QUOTE]Originally posted by cdelena

 

Poor lubrication of the diff will more likely cause galling or fracture or brinelling of the gearset.

 

i changed my differential fluid at 2k miles, it had metal shavings in it and im glad i changed it early. i used mobil 1 75w90 and the diff. sounds quieter now. i plan on changing the fluid every year or so, its cheap insurance for me and having access to a lift makes everything much easier.

 

I change my oil @ 3k. and my tranny and diff @ 10k

 

Got my diff. oil changed today. The tech said that it definitely needed done (i.e. the oil was dark). He also recommended that I change it again after 15-20,000 more miles, along with the transmission oil. He suggested going to synthetic in both, stating that it will help smooth out shifting a little and take some of the grinding noises out that many seem to experience with the S2000's transmission.
What has been your experience with synthetics in both? Worth it, or not?

 

I change my diff and tranny fluid every 10K miles.