Nowadays a lot is done by computer you feed in the parameters & it will adjust the parameters to give you component values, you change on bit & it re-calculates the rest.

When it comes to fixing, things are greatly enhanced by actually knowing how the thing works; as that underlying knowledge gives you greater insight as to why it won't.

We are loosing skills wholesale. I had a prime example last week. A neighbours Lawn Tractor had a steering arm snap off at the shaft. Dodgy weld, coupled with the flimsy construction of most of their steering; coupled with, I will bet, not being taught about steering.

It was taken to a dealer and sat there for three weeks. After claiming it would take a week to get the part. Which apparently is discontinued. So I won it. Apart from some dodgy work welding that which never was originally, requiring some angle grinder work, it just required a bit of dismantling to get at it & get it out.

A bit of rebuilding with a MIG welder was needed to sort out that bit of damage and with a tad of bench grinder work the broken arm was welded back onto the shaft with a bit of extra metal added at the weak points. Even that being done in dribs and drabs between farm work, it came in late Monday & was serviced (oil change etc) and ready to be used by Friday arvo. What were these people doing?

Must have been under the misapprehension that he would buy another. However, with a performance like that, not from them.