Hi,
I recall reading that the rear diff oil should be changed once at 3000 km and then it’s good for life. However, the service manual says once at 3000 and then every 4 years/60000.
Which is correct?

thanks

 

Rear diff oil isn’t good for life. Whenever in doubt, follow the schedule in the service manual.

 

Also depends if you have a limited slip - if you don't have a limited slip there is no recommended change at any mileage - if you have the Limited Slip, then at 2k miles then every 40k miles.

If you don't have a limited slip, I would change it but since there is no material contaminating the fluid like in a limited slip, probaby 60-75k is when I would change it.

 

What is a reasonable cost to get this done at the dealer?

I do my own oil and brake fluid flushes, but I don't have a lift...