Learn Diesels

Grease Monkeys Unite!

21 Tips Every Diesel Mechanic Wish They’d Learned Sooner

Johnathan CokerHow Tos

I wanted to put together a list of help for that struggling mechanic out there. Sometimes even after years of turning wrenches there are tips and tricks that the old man in your shop just never shared.

In my shop we had a wise old mechanic. We will call him Frank. Frank would wait until you were almost done with a job and walk up survey your work, clear his throat and say, “that’s not the way I would have done it”. 😆

He was hilarious. But the funny part is he never offered how he would have done it. So, with that story in mind I wanted to compile all the great advice from all the great mechanics I know and share it with you. Maybe you’re asking, how do I become a better diesel mechanic? I think this list will help you get started and keep you away from those rookie mistakes.

1. Work smarter not harder

A classic here. This is often an overlooked aspect of our jobs. When you are younger it is easy to get that bull in a china shop mentality where you just blow through whatever task you have before you and think about it later.

When you get some experience, you realize that that your body is not going to last forever, and you need to think about what your doing. I had a buddy that always said we have to find the lazy way. This is so true!

You need work hacks. Hacks to make work faster and easier on your body. A very wise old man once showed me how to remove brake drums (which weigh an average of 111 pounds) without killing your back if you don’t have a drum truck.

He used a hand-truck and after smacking them a couple times with a 5 pound sledge, he pulled the dolly under them and popped them right off and they fell safely on the dolly.

Work hacks. Learn them and use them. You only have one body. You are unreplaceable. Take care of yourself.

2. If there is a special tool for the job, get it

Ever hear, “There is a right tool for the job”. It is so true. You can spend all day trying to do a job that would only take a couple minutes if you were using the right tool.

This happens a lot with stripped bolts or broken studs. They make awesome tools to fix these problems like ease outs and stud removers. When you use the correct tool, work becomes way less frustrating and you time on jobs will improve.

Can’t afford that special tool? There are so many special tools in diesel mechanics. You can’t buy them all. See if the shop is willing to invest in it for everyone to enjoy. You can also borrow one from a friend but take of it! Clean it when your done and return it as soon as you finished.

3. If it’s in the way, remove it

This is a hard pill 💊 to swallow sometimes. When you need to remove water pump and it looks like it might clear the alternator you may struggle for hours trying to get that square peg out of the round hole. Just remove the alternator.

Bite the bullet and remove the part in the way. I have wasted so much time trying to get something loose to replace it with another component in the way. Just take whatever is standing in the way off. It will save you hours and smashed fingers.

4. Inexperience overtightens

Something well known in the mechanic community is that new guys tighten things to tight. I understand this. When I first started the last thing I wanted was for stuff to fall off. So, you tighten things with a gorilla grip.

I have fought more than enough oil filters put on by the new-guy than I care to remember. This also leads to broken bolts and stripped aluminum threads. That he-man strength you are eager to show off when you are young, can cause some serious problems for you in the long run. If it in a ¼ bolt and you’re going into aluminum be careful! Don’t tighten until you hear a Tink!

Get a torque wrench. They are your friend. You need to get a feel for what is appropriate tightness. Use it on everything. Most all bolts have a torque spec. If it doesn’t have one for the specific thing you’re working on, you can use a chart for bolt size.

5. Buy a good ratchet

Any mechanic worth their salt is going to have a favorite ratchet. You use this tool every day. Buy a good one. It is like buying cheap shoes. You use them every day all the time. Buy nice ones!

You don’t need to go on the truck for one either. There are some great ratchets out there that you can get on amazon and save a ton compared to Snap-On. I love this GearWrench set. Whatever you buy, by a good one and never look back. Your knuckles wills thank you.

6. Ask for advice and Listen to advice

Don’t sit and work on a problem for hours with no end it sight. When you start out more experienced mechanics don’t expect you to know everything. The longer you keep working without really knowing what to do or where to go from here, the more the other mechanics will give you are hard time about not asking sooner.

Just ask! Usually, your co-workers will help you. I never minded a question from a new guy with a good attitude. Just be humble and ask for help. Now the important part

Take the advice You don’t know best if you are asking. There was a guy in my shop the other mechanic and I would help, he would listen and then go ask someone else and then try it his way. He did not make friends like this. Here’s a couple rules regarding advice.

  • Don’t go for a second opinion. It is insulting to the person you asked. When you have asked, go back and put that advice to work. You don’t know if its poor advice until you try it. Instead of asking two or three people ask the right person the first time

  • Don’t argue with them Listen. You mom always said you have two ears for a reason. Sound advice.

  • Don’t do it your way When you do, and you break something you look real dumb. Seen it first-hand. Don’t be that guy.

7. Wear safety glasses

Care about your eyes? You cannot replace them. A doctor might but, who want to experience that? Just wear the glasses and save yourself some pain and money. Yes, I know they are uncomfortable, and I know they fog up. They are a pain. It doesn’t matter. Your eyes are worth the hassle.

My ship we didn’t have to wear them all day, which was nice. Always have them on when you need them, and you know when you need them. Anytime you are working under a vehicle or with solvents grinding and other things. Be smart.

8. Go get a cup of coffee and come back

I admit this used to be go smoke a cigarette and come back but, those days are gone. Smoking is bad people. Just quit it already. 🚭 So, when you’ve been looking for an air leak for 5 hours and still everything you have looked at has no bubbles, just stop.

Go so something else. It is proven that when you give your brain a rest that it continues to work on the problem while you do other things. Sometimes you just need to focus on something else for a while and when you return the problem will become clear.

9. Follow the instructions

Today’s diagnostic tools are so much better than it used to be. They offer a lot of help when it comes to trouble codes and repair steps. Your shop should also have the repair manual for all your vehicles. Open those pages. Follow the instructions.

A lot of times the guy that becomes the diesel tech it the skip the instructions guy. This is not good 😆. We need to go step by step and follow the manufactures specs. Not all the time but, for sure when you are working on engine internals.

10. Take a picture. Mark your spot.

It is the worst when you are trying to put something back together that you took apart a month ago because that parts were on backorder. Now you are stuck trying to remember what went were and how it was supposed to look. You put one part on and then realize it can’t go on until you put on another. The worst

Take a picture with your phone. It is so handy just to snap a photo showing how everything goes and if its real complex you go take a series of pictures showing the steps.

When you are messing with alignment and timing a bottle of white-out is your friend and then even snapping a picture of that. Mark your place, take a picture it will be worth a thousand cuss-words.

11. It’s not going to the moon

When NASA puts a rocket ship together everything is scrutinized, and each bolt and part go through a rigorous process of certification for space. When you are working on a dump truck the same scrutiny is often not needed.

I am not saying do a crappy job or sloppy work. I am saying that taking a tiny issue way too far and wasting time is not a great idea. Not every problem will get fixed every time it’s in the shop if you have a fleet. Sometimes they have to roll with a tiny air leak. Just always put it in your notes and let the boss know.

12. Disconnect the battery

I have a chicken fried finger to show for this one. Always disconnect the battery. Every repair. I was helping a friend remove a turbo and on this particular unit the starter was underneath it. My ring turned 🍒 cherry red. I now wear a silicone ring. They are cool and comfortable. Check them out on amazon Here.

If you notice removing the battery cables are usually the first step in most repairs by the book. For good reason. You don’t need to get a burn or short something out. Just do it.

13. Speed Kills

When you try to beat the best time for removing a radiator mistakes will be making. Fingers will be smashed. Fast is good if you really know what you’re doing but even then, its best to just pace yourself.

When you are new don’t try to be fast just work at a steady pace and don’t stop to talk or tweet or whatever. Just stay at it. That after all is good work ethic. Not how fast you work but how steady and reliable you are.

14. Measure twice, cut once

A classic. I wish I would take this advice more often. I had a friend who always cracked me up who would say, I kept cutting it and it was still too short. This is important and really goes with taking you time. Think before you cut.

Sometimes you don’t have any more of that material and it’s important not to waste it. Maybe its flex pipe or electrical wire. Take your time and make sure you give yourself some extra.

15. Listen to the driver’s story

Often overlooked is the confusing and sometimes hilarious driver story. So, they come in the shop to let you know what is wrong and maybe if you’re lucky how to fix it. 😆 So you sit back and listen trying not to roll your eyes and they tell you how to do your job.

The drivers at one place I worked always liked to tell the mechanics that they had it made. To this I would always reply, The only way my job would be easier is if I had a steering wheel to hold. But, with that said, there in some truth in those stories if you know what to listen for.

Don’t just dismiss everything they say just because their annoying. Listen for info to help you fix it. If they say it won’t pull. That could be lots of things but if you’ve heard it before you know to check the turbo clamps intercooler for leaks and so forth.

This really just takes time and experience but don’t just dismiss everything they tell you. You can find out a lot for the guy who spends hours in the cab.

16. Ask for help

In diesel mechanics everything is big, and the parts are heavy. Sometimes you need a hand. Whether is removing a drive shaft or lining up a tranny, some jobs need two people. Don’t be afraid to ask for a hand. It is not worth the back pain. Get a friend and team lift it.

17. If you borrow it twice, buy one

A good rule of thumb for a new mechanic. Look I am sure your friend doesn’t mind loaning you his automatic wire strippers but, after a few times you should realize you need one yourself and just come off the money and get you one. Again, when you do borrow something, take care of it. Clean it up when you are done and take it back ASAP after the repair.

Don’t hold on to it for weeks and make them come and ask you for it. Be contentious, think of others. That’s not how you would want people to treat your things. Tools are expensive, but if your borrowing all the time just go ahead and pick one up.

18. Clean your tools

Overlooked important tip here. When you clean your tools after every job, you do a couple things

  1. You keep up with all your tools. When you clean them and put them up you are more likely to notice that missing wrench you left in the frame rail.

  2. Your tools last longer. When you take care your tools, they take care of you.

  1. The correct time gets charged to the job. Cleaning up is part of a repair. By cleaning up after each repair you charge the correct amount of time to the job and avoid overcharging others.

19. Who’s name you want in the paper?

Your work is important. The person operating the vehicle or equipment is depending on you to do a safe repair. As a mechanic you can put the operator in danger in sub-par repairs or incompetence. If you are going to do the job do it well!

There is a shortage of really great mechanics and if you are starting in this industry make that your goal! Be great. You will have a since of pride and the people who use the equipment you work on can do so with confidence.

In this industry your name is important and each repair you do has your name on it. That means that when it has to be done again everyone will know it was you. Take pride in your name and do great work.

20. It’s not the ECM

As a new guy, diagnostic work can be tough. It is arguably the hardest thing to learn. It takes years to be able to understand and diagnose issues. So, as the new guy when you ant figure out the problem the temptation may be to go to the worst case scenario. You might think, it’s gotta be the ECM.

In 15 years, I think I have replaced 2 ECMs so I am not saying they can’t have issues. I’m saying that the simplest problem is usually the right one. Maybe you missed something. See ask for advice.

21. Life’s too short not to love what you do

Have fun. Play practical jokes. Be nice. Make friends. Go out with your co-workers. I have great memories of funny things that we did in the shop and just crazy stuff that happened. You spend a ton of time with these people. Some of my closest friends are guys I have worked with. Don’t spend days complaining, be thankful and work hard.