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

Not double checking the lug bolt length provided by the shop and not realizing that they were slightly too long on... wheel spun fine up in the air when tested but when fully torqued down on the ground it caught just a couple of threads on the spindle and wore down. Not a huge issue by itself but backing the bolt out later resulted in a stripped hub requiring chasing with a tap. Not a Taco story mind you.

Oh and of course, losing a 10mm socket in the center console lol.

 

I work on heavy trucks and diesel equipment, and none of us like working on cars/trucks. there was a new kid at the shop and the bosses F150 Platinum Eco boost needed a new AC compressor so we thought we’d pawn it off on him. He was trying to roll the belt back on by turning the motor with a ratchet, but was turning it over backwards and I guess eco boosts don’t like that and it jumped the time and bent the valves. Boss got it towed in to the dealer and traded for a 6.0 Platinum.

 

Replacing the front wheel bearings on a Pontiac Sunbird and did a shit job of packing the grease in. It was more like rubbing than packing. Button it up, and 100 ft into the test drive and there's grinding. Got to do the whole thing over after bumming a ride to the auto parts store to buy another bearing and getting some advice from a friend that knew better. Who knew you needed grease INSIDE the bearing, not just slathered around the outside?

 

Recently I did a valve clearance check on my motorcycle.
It's an old-fashioned carbed V-Twin engine with valve shims.

It's a drawn out pain in the butt job.
After all the shim swapping and checking with feeler gauges I'm ready to button it back up.
Something told me I should carefully inspect the cylinders before putting the heads back on.

You know what's coming, don't you?
Yep, I somehow dropped a shim in the rear jug.
That would have been...bad.

Moral:
Any time you got something opened up, put tape over it or stuff a sock in it.
Something.
So nothing gets where it's not supposed to be.

 

The shaft where the kickstarter goes on a Kawasaki dirt bike stripped out so I JB welded it on. Which actually worked great. Until I decided to rebuild the engine and couldn't get the damn thing off. I finally gave up and got another bike.

 

I think everyone who has ever replaced a spin on filter has done this at least (and hopefully only) once. I know I have.

 

Did a seasonal tire swap on my first new car one year. Driving down the road a bit later my right front wheel is making some strange noises when I left off the gas. Pull over and see that I had forgotten to tighten the lugnuts all the way. Nothing damaged, but it could have been a very bad day.

 

A lot of these make me feel better about all the dumb stuff I do. I put wheel spacers on and I guess i just snugged up one of the wheels when I put it all back together because for a week there was a weird noise coming from my front end. Went off roading and it sounded horrible. Had my mechanic friend listen as I drove by. Checked my wheel and three lugs where gone and the other three about to fall off! And I had just drove on the freeway for an hour. Sketch.

 

Swapping the cam in my old '70 Camaro in high school. Was thinking about the cam break in, and forgot to put oil in the motor. Spun a rod bearing soon after.

 

bet you wish you still had that 70 camaro, i wish i still had my 67.

 

Yeah, wish I did. Hope it is in good hands today. I sold it in 1989 to pay for college expenses.

 

I had a Honda CRX SI back in the day. Changed oil and I forgot to put the oil cap back on. Few miles down the road I started smelling oil and the smell of burned oil . Pulled over and I realized what I did. The engine didn't lose a lot of oil. I was lucky.
But it was a hell of a job cleaning it up. Bruised ego , that's about it. Learned my lesson to check and double check on everything I touch.

 

Way back I had a V8 Vega
Did front breaks late one night, driving to college the next day on highway and car started thumping.
I slowed down but couldn't pull over because there was no shoulder
Next thing I know car drops and front tire goes flying down road
I was lucky - coasted to shoulder
Most damage to my ego, bent dust shield that was it
Had to be towed home because i had no spare

 

this is one of my favorites

https://www.tacomaworld.com/threads/halp.33318/

 

Back when I had a Supra 87 (maybe 10-12 years ago) I didn’t use jack stands cuz I was a broke ass kid and kinda uneducated on wrenching a car and was just using the scissor jack to lift the car and also support the weight. Also to note i was on the driveway with a small decline and didn’t even chock my tires.

And of Coarse the car went down but I saw it all unravel as if it was slow motion and got my foot out the way as the tire almost landed on it. So after that I watched a lot of YouTube and advice from friends.

Ever since I’ve been doing it the right way. You can’t see it but my rear tires are chocked, jack stands and using the jack as a safety precaution. Only thing I didn’t do was put an extra tire on the ground as an extra safety measure but I got lazy cuz I have extra tires laying around.

 

Redoing the fuel system in my old 94 4Runner and forgot to depressurize it.

 

I was rebuilding the motor on my 1982 Honda CB 650 SC Nighthawk when I learned about grabbing the wrong torque wrench.

 

When I was around 19 I put headers on my 69 SS Chevelle only using the bumper jack. On the damn street in front of my house.

Really like your truck, love that bumper.

 

Thanks!

 

I had a 1973 Kawasaki Z1 that I put a big bore kit in and I installed the oil rings upside down. No damage, but smoked like a house on fire. Spent the next weekend tearing it down and installing another new set of rings. They weren't cheap.