Dealership BS. How do Flat washers 'fail'?

Wow bad luck. A Prius may not be for you. G2 s can be a pain when they get old. On my second charge balance on my hybrid battery. The clock is ticking for me too.

 

I believe they are crush washers.
And if they failed, that's their fault too, as they should of replaced them when doing the service. Maybe why they refer to them just as washers on the invoice, is they didn't want you to figure out they made another mistake in not replacing them.

As far as the service adviser shuffle? I think that's fairly common. My experience with Service Advisers is often a real lack of actual mechanical knowledge, and the point of their interaction being to create an estimate and invoice you will sign, and to get a paid bill. They really just usher you into the detached waiting room and run interference between yourself and the 18 year old kid, that will be the one actually changing your oil.
In the Ye Olden Times, your service adviser use to be the mechanic that was actually working on your car.

Overall, there are differences in service departments. Some are better run, more efficient, more honest than others. If you aren't happy, about your only choice is to seek an alternate service department.

 

A crush washer is designed to do just that, being of softer metal than the plug and the pan, it deforms and creates a tighter seal than would be possible without it. Used to buy them by the handful when I changed my own oil. Always used a new one so it had the max crush-ability.

 

The crush washer for the trans I have seen "deformed" and didn't provide a good seal.

@The Critic had that happen once.

So not unheard of.

Once it happened to him, I was more selective for the washers I used.

 

I drove an extra 150 miles each way to avoid my local dealer for the wiring harness recall & taping. No way would I trust the judgement of the local dealer.