Time to change the lube in the rear end and in the M410trans/OD. I have a new rear cover gasket for the differential, so that's not a problem. But it's a long time since I drained the trans/OD. Can someone give me precise instructions for draining and ensuring a proper refill? (Note: I do have an OD sump gasket, and an OD filter removal tool. But I'm not planning to mess with the filters.)

Just as an aside, when I first got the car in 2001, the OD was cranky. I drained and tried the recommended 30w motor oil and there was no improvement. So I put regular 70w-90 gear oil in and it worked fine. But after speaking with someone at Redline about the harm that sulfur could do to the internals, I switched to their MT-90 and have never looked back. Pricy, but that's what I plan on using again.