Wow. Dumb things done while wrenching...... A few that come to mind right off....
1- Doing an HPOP install on a buddy's truck, underestimated the pressure of cold oil out the top of the HPOP reservoir fill plug, needless to say when we started it, i had an oil volcano that quickly puked out over a quart before we could shut it down....
2- Was changing the oil on my 6oh back in '09, changed the filter first(which as you know, is on the top of the motor) got distracted, and then started adding the new synthetic oil. I got 12 quarts in before i realized i hadnt ever drained the old oil out!
3- I had just done an excruciatingly tedious head gasket replacement on a toyota echo, and as i was testdriving it, i noticed an odd rattle coming from the timing chain cover area.... And as i was sitting at a red light pondering if i wanted to remove the valve cover to check it, it grenaded, ruining the head. Seems in my delirium late the night before, as i rushed to finish the project, i had finger tightened the exhaust cam pulley bolt, but never torqued it.... 15 years of timing and cyl head jobs, and all it takes is one key forgotten bolt. Those are the worst ones to do over....
I could keep going, but i dont want all of you to feel TOO good about yourselves.

 

this is me right here! the last time i about knocked myself out i split my forehead wide open with a breaker bar. laying on the ground trying to get the back bolt out of the leaf spring on my X the socket slipped off and i saw the light at the end of the tunnel....im a 250lb guy and was lifting myself off the ground i was tugging so hard then SLIP! and BAM! my 13 year was standing there and saw my face completely covered in blood and you would have thought he saw a zombie! nothing like splitting your own wig!

 

Yeah, I've whacked my face and head so many times. Whenever I quit cussing myself at the moment, I usually start to laugh...because it reminds of being a kid when you'd grab someone's arm (or they grabbed yours) and then slap them silly in their own face with it and say "Why are you hitting yourself, huh, why are you hitting yourself???" I feel like the idiot hitting myself when my hand or tool slips.

 

I grew up working in a truck shop....I cant even remember how many times I installed the valve stem in the inside dual backward ( toward the middle of the truck, not inside the tire).......of course you never notice until your pulling the jack out.

 

after doing atleast 3 hpop installs on other members trucks i installed a Termmy modded 17* pump on my truck
while putting everything back together decided to put a resistor in the ebpv plug
well after an hour of the truck running till it got warmed up and driving myself nuts
with help from Joey and Clay we figured out that the plug with the resistor in it was the ipr not the ebpv
needless to say it wasnt even throwing a code to help us lead us in the right direction because of the resistor ...

 

A couple of Tech Days ago I pulled the drivers side injectors out to put new o-rings on them. It was getting dark when I finished then noticed I had an extra set of o-rings sitting on the picnic table...

 

Rear end gears on the F350 were making noise so I decided I would fix it. Everything went well with installing and setting up the new gears. Reinstalled the rear end under the truck and filled it with oil. The jackstands were not level and the passenger side was somewhat lower than the drivers side and I didn't pay it any mind. Went on a test drive on a road with a lot of crown and again because of the crown the drivers side of the rear end was higher than the passenger side.

After about three miles I heard some noises. Tried to limp it home and didn't quite make it. Had to be towed the last 1/2 mile. Removed the drivers side wheel and saw that I had burned the end of the axle tube off.

This cost me a couple of grand. I guess oil never got to that side to lube the bearings.

 

OK, my stomach got a little queazy when I saw that pic!

 

I ran out of beer. Once.

 

you win....

I never understood why my Grandpa made me coat the bearings with oil when doing an inner axle seal, I always figured the diff would lube it like it was designed to....now I know why.