The car in question is not a Mercedes, but the concept is always something I think about regardless of make.

A few less mechanical people I know say to never do it. It can loosen up bits and cause it to go.

This car (Buick enclave) does have a serviceable tranny. I had it fully flushed at 100k miles. There is no removable filter.

20k miles later and it's shifting funky. Slipping a little. And the fluid leaks a little. Not much, just topping it off for the first time.

How do you all feel about this concept (I'm working on saying all instead of guys so we are more open to women on here. )?

Is this is an urban myth?

The shop said some Toyotas are non serviceable. I find this troubling.