2.) Physical Stress
Remember when I mentioned that there was imminent danger of bodily harm creeping around every corner? I wasn't kidding. This job is physically stressful. It will keep you in modest shape. It will keep those muscles from deteriorating. It will likely permanently injure you.
On those days that I make it all day without a single scratch I jump for joy. The usual day includes several injuries. My arms, legs, and hands regularly get cuts and scratches from reaching in to tight spaces trying to remove a component. At least once a week I get a deeper cut that involves wrapping my finger with a gauze and electrical tap under my gloves. I have bumped my head on the lift arms so many times I've lost count (or maybe, I have lost my ability to count due to brain damage). I have bumped my shins on protruding trailer hitch ball. We are still talking about short term damaging injuries here. Cuts, scrapes, and bruises heal.
There is long term damage as well. Every time you bend over and lift that truck tire to mount it you are likely deteriorating your discs in your back. Walking on concrete all day and kneeling on them is horrible on your knees, so they will likely fail eventually too. All those carcinogenic dust you are breathing and chemicals you are touching could easily increase your risks of cancer in the future. That repetitive wrenching motion and use of air pneumatic tools are slowly destroying the ligaments in your wrist. Ever look at a technician that has turned wrenches for 20+ years? They look old. They look tired. Their body shows the stress of the job.
There are good jobs out there that have similar risks. If possible carpal tunnel syndrome, lung cancer, and herniated discs do not deter you from this job, then continue reading. If you have all these risks you should be well compensated with pay, right?