Are there any arms in the army that repair cars?

Your major is very good. If you are healthy, politically qualified and everything, you can join the army. I suggest you join the army, because the armed police force has fewer arms and fewer personnel. The army is a big family and a society, and it needs many talents in all fields. With such good skills, I believe you will find the job you want better than those without skills. The army leader will send the arms you want to be a soldier according to your specialty. Good luck.