Every thing has a design life Slowie
And the master of manipulating this was one Henry Ford.
You may have heard of him.
He made cars
Famous for totally falling apart after 12 months because every part was downgraded till they all failed at about the same time .
The EU have a compulsory rating called the durability index so if
hyawatha15 bought his JD in Italy it would have a card that read "Durability , Frame = 7 years, Engine = 10 years Transmission = 10 years ,deck = 10 years for domestic lite use .
They can also specify it in operating hours .
The EU brought this in when they brought in end of life recycling at cost to the manufacturer so the manufacturers then had a reason to make consumer durables, more durable.
This is why almost any European product will run for 4 to 10 times longer than any USA product .
e were looking at "disposal tax" to be added to all consumer products which is reverse proportional to the service life to make long life products cheaper compared to throw away products . This is easier for us because we don't have senators & senior public servants in the pockets of Ford , GM . B & S , JD , Bezos, Walton family, Coke Brothers or even Prince Rupet wo want us to buy new every year .
The 100 series JD's are built to the same design as all of the AYP mowers to the point that a lot of the parts are interchangable
However the first thing I noticed was the 100's frame was pressed from heavier steel than the AYP Garden Tractors
Where a shaft went through the JD frame it had a plastic bush , the AYP runs directly on the frame
To make the frame last longer you either back spin the hole so it has spiggot in place of punching the hole or tacking a stiffener inside the hole to strengthen it .
Then there is the grade of steel,
All of these things drastically alter the service life