What is the worst mistake you made doing your own wrenching?

Was helping my dad rebuild my brothers 1999 Saab 2.0 turbo. Just got the motor back from the head shop and was putting it all back together. Was drilling out some pieces for a different project when the drill bit snapped and flew across the garage somewhere. Next day we get everything put back together and start the car up.... Hear this HORRIBLE knocking noise so we shut the car off as fast as we can and start pulling the engine apart again.... drill bit broke off, flew across the garage and then landed in an open cyclinder on the piston head.. then proceeded to get slammed into the newly rebuilt motor a good 20 or so times... good thing the head shop guy felt bad for us or that motor rebuild would have cost more than the car was worth....

Thats my worst story... so far

 

Everyone has a Saab story

 

Yes the amperage is extremely high. So it can be extremely dangerous. However it just causes sparks and heat. Small wires instantly turn cherry red and burn out. Much larger wiring will do the same it will completely catch fire. That being said you can touch the terminals all day and nothing will happen to you. If you touch a shorted wire you will not get shocked, or or any dangerous current through your body that will harm you. You will however get severe burns as the heat is very intense on a direct short. I’ve worked with 12v DC for 14 years and about 5 of those was installed very large and high current and wattage amplifiers. Installing plenty of capacitors and additional batteries as well. Starter motors can draw a lot of power. However they are not drawing 600 amps. They typically draw between 60-120 amps in newer engines. Older ones in very large trucks and motors maybe 100-200 amps. Those are going to be slow turns. Batteries are rated in cranking amps and cold cranking amps. Just because it had a rating of 500-800 cold cranking amps doesn’t mean that the starter is using that many. An audio amplifier in a vehicle is powered by 12v. However it’s amplifying the low line level from the head unit, into high level outputs for large subwoofers. Yes the output can give you an electric shock as it’s putting out voltage. This voltage isn’t extremely high. Most ratings with car audio are max levels not RMS values. Just like in your home 120 volt is actually more like ~175 volts peak. However the you’re seeing the RMS values in your home. There are a lot of details and variables when it comes to this stuff. But a normal car audio set up almost regardless of how many watts the amp is rated at on the output side won’t kill you. And you can’t be harmed at all just by touching the input (0-14.4) volts. Even if you put 20) 5 farad capacitors in line and an extra battery wired in parallel.

 

I’m not knocking all Harbor Freight stuff. Infact I have some stuff from there. Just like you said there is some things at are pretty good there and some things to just stay away from. I installed electronics and accessories on vehicles for 14 years. Most of my stuff is Snapon and I have some Matco stuff and what not. I also have some Craftsman stuff and Harbor frieght. When it comes to impact guns/electrical tools I always go named brand. But I used a HF airsaw, and air hammer. Since I used those only a hand full of times a year (if that) I couldn’t justify paying a couple hundred dollars for a good one. Those got the job done usually or I would borrow one from someone else. When it came to ratchet and stuff I used snap on. But I also had some of the Pittsburg open end wreches and some sockets. I could beat those to hell and not worry about them. And with the wrenches I had sizes I didn’t have with the snap on set and could use those if ever needed.

Most of the HF stuff I have I bought doing projects around the house. Things I may only use a hand full of times or less. I got a miter saw from there. I’ved Used it several times. I’m not a carpenter so I don’t need a really good one. If it breaks I got my money’s worth and if I do a big project like wanting to refinish my basement then maybe I would debate buying a nice Dewalt or something.

Anyways, HF tools have their purpose. I mean I’d rather the stuff be made in America rather than China, but I also know that it wouldn’t be as cheap as it is.

 

People often poke fun at me for taking forever to do projects. What takes you 1 hour takes me half a day, what takes you 5 hours takes me a whole weekend because I'm always pausing and just sitting there staring at my engine pondering how things work and what things do, why things are the way they are, and most importantly what my next move it.

But now I see threads like this and realize I've been DIYing cars for 15 years and never had a real fuckup and want to say

 

I was thinking this too. Now that there’s a thread dedicated to stupid fuck ups, everyone’s got a story and happy to spill beer together. In any other thread, the trolls come out en masse.

Those fuckin trolls got neutered by the context of this thread.

 

they're still checking the oil level....

 

Right, they’re taking notes!

 

Lol. A lot of mistake are made from rushing. Some are just poor decisions in hindsight. However I’m sure you have had a few oh shit moments?

 

Nothing on the truck, but plenty of fuck ups on the bikes. First ever was mixing up the oil filter cover bolts on my 2005 YZ250F, put the long one in too far and overtorqued the shit out of it obviously breaking it off in the case. Though it was costly and frustrating at the time all those mistakes taught me some valuable lessons for future wrenching.

 

Back in 1980 I was a shipboard engineering officer in the US merchant marines. I worked only on steamships and had a 3rd Assistant Engineers license, unlimited HP. I got tasked with changing out a leaking flexatallic gasket on the inlet to a cast steam turbine driven pump. We did not have any torque wrenches and I overtightened the flange and cracked the seating face of the 600 psi desuperheated steam inlet flange. We had no welding machines with that particular company so they had to send out for a shipyard welder to meet us in the next port. Almost 40 years later and I still remember it clearly ...

 

Worst mistake doing my own wrenching, was doing my own wrenching. A mans got to know his limitations

 

I worked briefly at an Autozone, and this customer comes in and asks for 1' of rubber tubing. Im just curious so I ask what its for...the guy says I broke my brake line and I want to repair it...I said Im pretty sure you dont want to do that. He says why?? its just liquid. I had to explain to him why he couldnt fix his brake line with rubber hose...

 

This post tells me that if you have not screwed up doing mechanic work that you have not done any real mechanic work. Even the best mechanics make mistakes.

 

I concur. I have managed as many as 100 people for a corporation and my old saying is "The only people who don't make mistakes are the people who don't do anything."

 

I was gonna defend myself but ehh I think i'll opt for a

 

LOL what you have done is show everyone on TW that you are an Idiot

 

I remember doing things like rounding off the top bellhousing bolt on my Camaro when pulling the transmission resulting in a half day of swearing, bending the fuel float arm when changing the fuel pump so when I was back on the road I ran out of gas with the gauge reading 1/4 tank, etc but I guess what I meant was I have thankfully yet to do anything that cost me hundreds/thousands of dollars. Knock on wood.

 

Thank you For the kind Words

 

not wrenching but I put together a tv cabinet with some pieces reversed really messed it up.