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

Years ago I forgot to put oil back in a car. Drained it, got called into work (drove a different vehicle), came home and the next day I totally forgot I never filled it and started it up.

 

Not me, but happened when I took my new to me 2016 Tacoma into the dealership back in April, about a month after i bought it:

I took the Tacoma to the dealership to have the oil changed and things checked out to make sure it was "up to date" on TSBs and such.

So about 3 hours later I get the call it's done and come get it. As the Service Manager and I were going over the paperwork, I didn't see where they changed the oil.

So I finally asked him if the oil had been changed and he tells me "it wasn't needed!"


Huh, so I asked him to pull up the service record and he's showing me that it had the oil changed at 7,000+ miles ago, just last September.... I then pointed out, yeah, September 2017!


He immediately apologized and said he would get the oil changed right away. And while they were at it, they replaced the in cabin air filter that apparently rats or mice had taken a couple of bites out of.

When I went back to pick it up with the fresh oil change, he told me that even though the "3 Years/25,000 mile" Free Vehicle Services expired the week before (3/31/19, six days before) that they were covering the service for free!


I was okay with that!




A couple of years ago, I had replaced my tires and brake pads on my 2010 ST1300 (motorcycle). I had gotten distracted when the wife came home with groceries and of course I had to stop what I was doing and go help! I was in the middle of tightening down the rightside brake mount bolts.

On my way home from work that week, when slowing down because traffic was going from 75mph to 10mph, I hit my front brakes and something wasn't right. I tapped them again and knew something wasn't right... I pulled off the freeway only to find that one of brake mount bolts was missing and the other mount bolt was halfway out!

Of course I had swapped bikes that weekend and forgot to put my tools in my topcase! A neighbor saw me on the side of the road and stopped. he had a 1/2" boxed in wrench that I was able to use to get a 12mm bolt out of the bracket holding on to the muffler, put it in the brake mount and that got me home, where I could get replacement bolts!

 

I was installing a transmission cooler on my radiator mount & had my holes marked & center punched real nice eased the drill between the grill & radiator mount & it wouldn't drill, I knew it was a good bit so I pushed a little harder & WAM rite through the radiator it went!!! I had the drill in reverse.

 

1st oil change on my 2006 4WD V6 Taco, I couldn't break free the factory oil filter. Neighbor came over with 3 different wrenches. Finally got it off. We finished oil change so I asked him if all his wrenches were accounted. I had mine. 3 weeks later, one of those wrenches wiggled its way and fell into the fan that blew it through the radiator. It happened when I started truck when parked. Thought I heard a noise. Got out, looked, & saw truck leaking antifreeze. Had it towed to dealer thinking it was a hose (totally forgot about wrenches), dealer called asking when I changed my oil last? So embarrassing to say the least. Grateful it didn't happen out when I was out wheeling up in the mountains the week before. I inventory every wrench now. Even my buddies.

 

Rebuilt the head on my BMW 1600, had to put the timing chain cog back on and set #1 piston to -10° BTDC, well opposite of that is +170° ATDC, which I did...I swear the engine ran backwards for a few cycles!

 

Me too… was so mad at myself

 

Ive done that lol now I have two little paint chips on edge of hood.

 

Not my worst but most recent lol. I was removing battery cables to put a set of subs in my buddies STI dropped the wrench and it arced off the battery to the AC line and blew a hole in it within a millisecond lol Last time I make that mistake

 

Don't know if it was a mistake as much as it was just shit luck, but I was doing my lower ball joints on my 04 a couple weeks ago and as I was finishing up the first side and torquing to spec the 4 (brand new OEM) bolts holding it into the spindle, one of them fking snapped in half. Of course the half that got stuck was up inside the spindle and I had to remove the brand new LBJ to get it out.

My mistake came when removing the new LBJ, in my frustration and haste I ruined the boot getting it off which compromises the joint. Not wanting to take any chances, I had to run out and buy another one from a dealer an hour away.

 

Worst mistake was not doing my own wrenching and taking it to the dealer for free Toyota "Care" service.

 

Yep I've done that
Flipped it then ordered a new set that night

Also took my wife's Pathfinder in for service at a reputable shop. Drove it home, the next morning I wake up to a small puddle of oil under the car. I think oh shit what's wrong with the car now? Turns out the drain plug was just hand tightened, I wrenched it gudentite, and do all of her oil changes myself since then.

 

Done this before. It's the oil pan gasket that makes it difficult to torque down.

Nothing bad has happen to me while wrenching thankfully, but I once purchased a Civic that was used for road race from an old friend, and on the first drive taking it home, it was making a horrible scrapping sounds while braking, when I finally make it home and inspect it, I discover my buddy had installed new brake pads the wrong way with the metal portion of the pad against the rotor, ended up having to replace the new rotors and pads he installed with new ones again.

Another story with the same friend and same car, went to have it smogged so that I can transfer title to my name, smog shop told me it had a CEL, but there was no light indicating that on the cluster, asked my buddy about it and he said he couldn't figure it out so he just pulled the bulb out of the cluster so he didn't have to see the CEL and forgot about, he ended up giving me 1000 bucks back for my trouble. I decided to check things out myself to see what he had done, and plugged an OBD2 scanner into the port, CEL popped up for O2 sensor, checked it and it was unplugged, plugged it back in and problem fixed, 5 minutes literally of diagnosis and work.

 

Not true. Welding is welding. The bolt still sees the same heating /cooling. That's the only thing that hardens steel.

 

Yup. Did that with my 17, only to later discover they apparently decided to put the oil canister on via 3/8 impact....

 

Cross threated a spark plug on my previous truck. Funny thing is, it was my last plug and i decided to have a beer and fucked it up.

Thank god i have a buddy who owns machine shop. He was nice enough to come by and insert a heli coil on the spot and it was good for 5 about years and then i sold the truck.

Miss that thing sometimes still.

 

Spark plugs on my wife’s iQ were/are insanely difficult! Car had a “miss” before, ran great after. Worth it considering what the labor would have been!

 

Used a cheap T50 torx bit to install a new custom steering wheel and you see the results below. Lesson learned; Always use the best quality tool you can find.

 

Yeah ford tech here, love doing explorer struts/strut mounts but you have to bungee that axle up while your doing the strut.

 

I just used the tailgate to rest lumber while I cut it. You can guess the rest lol

 

I hate drum brakes it seems like I have to redo usually 2x to get the parking brake to work. I've done a few of prementioned errors.