When we first moved to Maryland, we had to get our cars inspected to register them, and my wife’s GMC Yukon failed for having a leaky steering box. I decided I should just overhaul everything since I was going to be in there installing parts and that way I wouldn’t have to mess with it again later. In went a rebuilt steering box, new pitman arm, idler arm, inner and outer tie rods, and swaybar links. Everything went together fine, the car passed inspection, and we’ve been driving it around with no issues for months.
But my wife has always complained that it had a slight rattle over bumps. I have jacked it up and checked everything out more than once, but I couldn’t find any problems – until today.
I crawled under the car without jacking it up and discovered both swaybar links were loose. How did I miss this? I didn’t discover the loose links before because when the car is jacked up and the suspension is at full droop, the slack in the loose connections gets taken up, and they stop rattling. I checked the repair manual, and sure enough, you’re supposed to torque down the links with the wheels on the ground. A half-dozen ratchet turns later, and no more rattle.
The moral here, I guess, is if at first you don’t succeed, go back and read the instructions.
Your turn: what wrenching mistakes have you had to go back and fix?
Was recently doing a timing belt job with son on his newly acquired 2000 Audi TT. It was a big PITA and took several evenings. Got the belt on, tensioned, and started rotating the engine by hand, my son up above watching the cam while I watched the crank. After about a quarter turn he said “STOP!” and told me to come see. We looked at the belt, saw the Audi logo, and realized we had put the old timing belt back on!
Whoops, but at least we caught it then instead after buttoning it all back up. After a brief swearing break, it took about an extra hour to figure out how to compress the tensioner, get the old belt off, and the new belt on.
Did this with my Volvo now I tear the box open first
We had both timing belts side by side to transfer the timing marks and they got mixed up from there.
Not even 2 days later the brake lights started working intermittently. Replaced the switch, lights still worked intermittently, started going down the rabbit hole of bad wiring before I released I had installed the old switch.
It’s a sign I needed a little break from car repairs. That said I’m doing inner tie rods on the Mazda 5 this weekend. Will mark old parts…
For myself, the more appropriate question would be, Have you ever Not made a wrenching mistake you had to go back and fix?
The answer is almost always no. It happens to me so often that I don’t even really get frustrated by it any longer. More like amusement at my dumbassery. However, because it’s happened so often I now double, triple, quadruple (you get the idea) check everything I do. So far I’ve done nothing too stupid, but there was that one time I totally missed tightening those caliper bolts and sure had an interesting test drive. Duh-me.
It was pretty low level in the realm of wrenching screw ups but this weekend, I replaced the ignition coil and plug wires in my Miata. Took it for a spin around the block and it was still running like crap. Then it dawned on me that I should have replaced the spark plugs at that time as well. After another trip to the auto parts store for fresh plugs, things were back to normal.
If you don’t have time to do it right, you’ll find time to do it twice!
If you can’t be handsome at least by handy.
~Red Green
We put the “re” in research.
Best friend/co-author about our time in grad school.
350z brake caliber bolt.
Me and my father did the brakes on my 350z a while ago, at the optimal time of 9 pm. We buttoned the car up and all the brakes worked fine.
However, when I began to daily drive the car, I started noticing a clunking noise over bumps. Thinking that this was just how the suspension sounded (I didn’t drive the car much prior to this so I had no reference,) I continued to drive it.
After a bit of driving, a series of epically catastrophic events occurred.
I ran over a little bit of rubber on the road, which usually isn’t a big deal. However one way or the other that piece of rubber hit the suspension hard enough that it ejected a loose brake caliper bolt that one of us forgot to tighten. For two miles I very gently limped the car back home, not knowing if the subframe was falling out or if any other dire components were failing. The clunking sound over bumps and potholes (there are many in that stretch back home) was very, very loud. Once home, I used an Ace Hardware bolt and two pressure washers to replace the other bolt which I couldn’t find at any auto parts store.
That was not fun. Moral of the story: don’t do brake work at 9pm.
I’ve had to go back lots of times, but the most annoying one I’m about to redo is rebuilding and rebooting some CV axles. The rebuild went fine, but when I was putting on the new inner boots I noticed the lip that holds the boot in place had more of a rounded edge on it than it should and that I’d be smart to file the edge square again. Sure enough, the boot slipped off of the lip on both sides and now I have to pull the axles to reclamp them (there isn’t space to reclamp them in-place).
I put the 1-2 shift lever on upside down when I reinstalled the 4-speed transmission in my ’60 Chevy El Camino. 2nd was where 1st was supposed to be, but 3rd and 4th were normal.
First time I drove it, I instantly realized what I’d done. But I was feeling lazy and just drove it like that for month or so.
I once didn’t fully tighten all the injector lines on a Maxxforce 7 equipped truck.
Took it on a road test, and about halfway through the loop, the oil pressure started dropping. I realised my mistake and it was rapidly diluting the oil with diesel.
I made it back to the shop under my own power, but with only about 7psi of pressure at idle (they should have 40).
Thankfully, no damage and those engines always blew up something else long before bearings could ever wear out.
Recently I broke a front strut spring and decided to replace both front struts for good measure. When doing the first side I completely missed that there was an alignment tab that needed to match with part of the lower strut mount. It was a pain to get installed but I just assumed it was normal midwest rustiness getting in the way.
When I did the second side I saw the tab and just groaned knowing I’d have to redo the other side. It did go back together easier with the tab in the right spot and the bolts weren’t rust-seized the second time around.
I have a fun one that’s not mine. In HS my friend and his dad were completely restoring a 1970 442. They were meticulous at restoring things (usually slot machines and juke boxes, but anything really). Complete body off restoration. built a rotisserie for the body from scratch and everything. Even went as far as to clear coat over the bolt heads after tightening. Thing was immaculate. Installed the motor and the thing immediately overheated. Caused the block paint to discolor and metal parts to blue from the heat. Had to pull the engine and strip it down completely in order to repaint the block and replace stuff.
Turns out they had installed the thermostat backwards iirc.
That’s about the time I realized perfection is probably not worth it and stopped dreaming about perfect cars and more about driving them.
Project BRAT. Didn’t wait long enough for all the penetrant I sprayed around the rust underneath the rear and torqued a brake bleed valve too hard. SNAP. Now it’s broken off and there isn’t enough to grab sticking out. It makes me sad just typing it.
It makes me sad reading it
Not a wrenching mistake and more of a buying mistake. I bought my current (and first) car for 600$. I bought it because it was cheap and I needed something reliable (it was the ’98 Civic I mention here and there). But, what I did not realize when I bought it, that my tall frame does not fit very well, and only after buying did I realize my head is touching the roof at almost all times.
ditto here with a 96 cavalier. Drove that thing for years with the seat reclined way more then I prefer.
Yeah 6’1/2″ does not mix well with a Civic coupe. 😛
I’m 6’4″ and my issue was that I had already tried a Cavalier coupe but it didn’t have a sunroof. The one I bought DID and it turns out that the little trim they put around the sunroof opening effectively reduced the clearance to the drivers seat by enough to make a difference. And I like to sit upright (like nascar upright) so that sucked.
Drove a cvcc for years. Solution was a hacksaw and a stick welder applied to the seat mounting brackets. I’m 6’5”.
A recent one… I just put a new soft-top in my NC last weekend and got everything reassembled, only to find two plastic interior trim pieces on my shelf that go in behind the rollbar someplace. I can’t even see them after everything is assembled. They don’t seem important, but since automakers generally don’t put something in that doesn’t serve some purpose, I figure I should go back in at some point soon and put them in. It’s probably an hour of removal and reassembly of the interior to get to where they go. But I know if I don’t put them back, they will have been critical to water drains from the top or something.
I just wired DRLs into my Elise. Did a fantastic, clean, OEM looking (considering how patched together the Elise is in spots, granted) job. Ran the circuit to an ignition source so they come on just like a real DRL circuit would, and grounded them through the for the driving lights. Built my own mounts, painted them matte black, used OEM headlamp socket plugs that were split with the driving light circuit , all looks perfect and is all completely reversible.
Drove one day before I realized that I forgot to put a fusible link in the additional, exterior circuit I tied into the circuit for the brake lights that is primarily outside the car and immediately started lightly panicking because it was raining out and I was driving it when it came to me.
Not retorquing the cylinder head. Now I get to rebuild and install the head again.
I did not follow the correct procedure for tensioning the timing belt on my 01 Miata. I didn’t find this out until about a year later when the belt failed very prematurely. Thankfully it is a non interference engine so I was back on the road for the cost of a tow and a new belt. Lesson learned.
I accidentally bought counterfeit sway bar links for a Ford Escape. They failed in less than a year. When I ordered a new set I saw what Moog packaging actually looks like and realized what had happened.
I recently replaced the struts on my Prius, which requires pulling the wiper assembly to get access to some of the nuts. Went pretty smoothly for a 17 year old Midwest car, but when I put everything back together I forgot to plug the wipers back in. Luckily I discovered this when I tried to use washer fluid and not in a thunderstorm, but I did get to drive around with a windshield full of dirty washer fluid until I had a chance to go home and take the cowl apart so I could get at the wiper connection.
Did a drivetrain swap in a Subaru XT with a WRX engine and trans. After hooking everything up and wanting to do a quick test drive, discovered the clutch fork moves the opposite direction from the XT.
Helped a friend install a 351 Cleveland into his 66 Mustang. Being young stupid but enthusiastic high school car hackers we did no research until we were trying to fit the wayyyyyy to large Cleveland into the engine bay. Ended up taking about 4 months to accomplish what we estimated to be a weekend job. Eventually made it work after much conferencing with local speed shops, ford experts and the local Ford, Lincoln, Mercury dealership parts counter experts.
Car ended up being fast and fun!
I adjusted the valve clearances on my Fit incorrectly, and the valve cover gasket was also sucking air. Little dabs of RTV to keep the gasket fixed the sucking, but I’m not entirely sure what was wrong with the valve adjustments. Doing it a second time improved the result significantly. She still doesn’t purr, but at 147k miles, I’m not sure if purring is to be expected. The ticking was reduced noticeably, and I gained 5-10% better MPG and about 500 RPM at full throttle under load/uphill. Reasonable PITA to have to do the full deed twice
My NA Miatas radio, a mix of my mistakes, previous owners mistakes, and doing other jobs resulted in me wiring and installing a head unit 3 times in 2 years. First was on buying, an aftermarket head unit was in the trunk, incorrectly wired. Were talking signal to ground, power to signal, etc. Rewired it entirely with correct splices, and it wouldn’t power on. Upped the amperage on the fuse by 5A, and it started smoking.
Due to it being older, even the same company switched connectors, so I had to completely re-wire it for a new head unit connector. Got it done and it worked flawlessly first try with no issues.
Fast forward a year, and in doing things in the interior with the seats out, I discovered my car did in fact have headrest speakers. The connector for the seat and harness were both there, but the wires never made it back to the head unit. Still no clue how this happened, but determined to have working headrest speakers, I created a harness from scratch with red and black wire, twisted them into pairs so that L/R channels worked properly for both seats, and routed them to the head unit and spliced them to the harness. this also sucked monumentally, but it worked!
Did I mention I really hate wiring, but really enjoy a working sound system?
I had an issue with an NA miata where if I turn on the parking lights or head lights the brake light fuse blows. Set aside a day to figure out where the short is and to upgrade the radio. Tore seats out, removed carpet, tested every section of wire and couldn’t figure out where the problem was. Gave up and swapped out the radio. Turned out it was the radio causing it by shorting either the ground or 12V to the backlight wire internally.
That really is something. If there’s one thing I’ve learned about wiring it’s that I don’t know anything about wiring, and if it looks janky, it is. Mercifully my only other electrical issue on my NA was a headlight motor burning out, and it did so as comically as possible. Had a friend in the car, going through all the stuff on it, and I proudly stated “the headlight motors even both work!” as I popped them up. Upon pressing the button again, only one went back down.
Fun part was, it shorted internally and was continuously drawing power and heating up a concerning amount, so I actually had to disconnect the battery until a replacement came in.
The biggest “woops” on my part was when I broken a piece of a chisel off replacing the intake manifold on my ‘69 C10 I daily’ed in college. Didn’t see the chip, it fell down into the engine, and after reassembly it wreaked havoc in the engine. Broke a piston and chewed up the cylinder wall as I recall. So, yeah, that truck wound up with a lot of “re-doing” because of a simple mistake.
Every temporary solution quickly becomes a permanent solution.
Installing amp wiring:
“Let me just hook everything up and make sure it works, I’ll clean up the wiring later”
“Yup, it works, better not mess with it”
I’ve done a couple installs now where “let me test it with wire nuts and I’ll solder everything later” turned into “the hell with this, I’ll just tape over the wire nuts and zip tie the tape around the wire”
That’s how the wiring in my camper is done. From the factory. I had delusions of organizing it with busbars and whatnot. But it works, so best not touch that spaghetti until it’s absolutely necessary.
Arrgggggg heathen!!!! I’m an EE. This would haunt me anytime a came near the car.
I once neglected to fully tighten the lugs on my wife’s wheel after replacing the rear hub bearing. I hadn’t put the torque wrench on it to fully tighten them.
I realized it as she was driving to work and called her and told her to stop if she heard any noises. She made it to work and back fine and I torqued them up.
Back in the mid 90s, I had a 70 Jeepster commando that leaked every single fluid. I had a persistent gas leak and after about the fifth time of pulling the tank to patch it I finally took the tank to a professional tank restoration place and had them epoxy seal and weld up the holes, finally it was right and that was my lesson.
The lesson I fail to learn over and over is ‘sometimes you just need to pay a professional to do the work *correctly*’
I fixed up a rust bucket Commando convertible during the last year of high school, finished up the body work, rewired the tail lights and finally got plates. First drive to the gas station, pump it full of gas only to hear fuel dripping profusely. The tanks was rotted just above the side seams on both sides.