It would surprise me. I grew up in the southern and western part of our country and worked in mechanical shops from Texas to North Dakota. Even owned one for awhile.
I heard those stories about metal in the drain pan and oil on shocks 60 years ago and they were old then. They are nothing more than mechanical folklore.
They are made up stories just like the sideshow at a carnival. In real life I never saw or heard so much as a hint of it really happening
Most mechanics fix things because they like to fix things. And they have more than plenty of work.
So if mechanics don't do that, you have to ask yourself if it really happens.
Also ask why would anyone do that? What would be the possible benefit? The mechanic doesn't make a dime if he replaces your shocks or does your transmission un-necessarily.
Think about it. A lot of those stories just don't make sense.
rScotty
He made the price of a set of shocks or a transmission, didn't he?
When I was pumping gas the owner tried to get me to sell a quart of oil whether the car needed it or not. (That job was what made me decide to go to college.)
In the case I mentioned above, the mechanic tried to sell me a tranny, telling me that the overdrive was going, which was a common problem. I went home and called the garage of a Dodge dealership downstate, which supposedly had the best Mopar reputation in the country. What he told was this;
"It's not uncommon to have metal filings on the magnet in the drainplug; that's what it's there for. There had been some problems with the OD in the Caravans but not in the Dakota. If the overdrive was bad you changed the OD unit; not rebuild the entire transmission."
Despite his claims that it was about to fail I put another 100K miles on that truck w/o touching the tranny, including having it serviced; when I sold it, the guy drove it home.
I had a local shop working on my Ranger. I thought that it needed an unusual amount of work. One day I had the rear brakes replaced from the wheel cylinders out to the drums. About 6 weeks later I walked out of the store and the brakes felt funny, so I stomped on them while sitting in the parking lot; and they went to the floor. The RR frame was covered with brake fluid so I thought I must have lost a brake line,as everything else was new. I took it home, pulled the new drum, and discovered that the wheel cylinder had failed... because the shoes were worn down so badly. He had put new drums on but never changed anything else, yet charged me for all new parts. I had just come home from my parent's house the day before, I'm lucky the brakes didn't fail when I was driving through town.