[G30M]

When you take your M3 in for 1500 mile break in service they change the engine oil and M diff oil -

I was wondering why not the transmission oil?

Transmission also has moving parts metal on metal!

Thanks for any explanation!

[Froz3n_M]

From what I know and got done on my car by dealer at 1011 miles (roughly) was diff oil and engine oil. The end

Trans service is probably not warranted for the current usage. It has huge magnets on the pan which catch most of the filaments. I don't think other pans in the car have such big magnets.

[TrackM4x]

Originally Posted by G80M4

When you take your M3 in for 1500 mile break in service they change the engine oil and M diff oil -

I was wondering why not the transmission oil?

Transmission also has moving parts metal on metal!

Thanks for any explanation!

Compared to engine oil and diff fluid, your trans fluid is clean at 1500 miles. There are filters and magnets in the pan to take care of the break in metals, and there isn't any combustion or high heat like the engine oil is facing that causes the trans oil to oxidize and get contaminated. I would only say changing it annually is needed if you are regularly tracking it.