The 'significant other' (SO) of our house keeper drove her 2003 Prius over a curb busting two slices out of the sidewall. It was in the business parking lot and she got management approval to effect repairs. PROBLEMS Only two lug nuts could be loosened for removal. One lug nut was 'rounded' ... no faces for the wrench. Second lug nut outer shell was 'loose' and no grip. The SO had used the mini floor jack on another car and 'it fell' He'd unscrewed the relief valve so a small amount of the hydraulic oil had leaked SOLUTION I went home to change into car-work clothes and gather tools including a floor stand. The first attempt to raise the car revealed the relief valve was at least 3-4 full turns unscrewed. Still, we didn't have another jack so as we jacked up the car, the mini jack twisted and raised up a pair of floor wheels. HUH!!!! We let the car down only the lift did not go all the way down. Wth!!! It seems the jack frame was a little bent and a pin on one side of the lift was 'catching' on the side rail. With everyone clear, a tire tool and educated guesses, we got it to go down. But now we understood why the pressure release valve was nearly unscrewed ... the pin catching on the side would not let the bent jack lower the lift. <SIGH> Repositioning the mini jack to minimize any lateral stress, the car was raised enough to lower on the floor stand. At least it would not fall again. We started with the rounded lug nut because that seemed the worst one: Using Dremil rotary tool, a cold chisel, and 2 lb sledge hammer, we soon learned there was an outer, metal shell, that surrounded the mechanical lug nut. But no amount of hammer and twist achieved any rotation but we did take some bites out of the nut. As the rains were rapidly approaching, we called it a night and return the next day with the drill bits. One of the engineers came by and told me about 'lug nut remover sockets' and I looked them up that night: A hardened socket, they have internal flutes that 'dig into' the nut with no requirement for the six-sided faces. In effect it forges a grip on the nut, rendering it a useless but removed former lug nut. At least the wheel can be removed. The next day Josh and I went to the local Sears store and with the good lug nuts, found the multi-socket remover tool and a 1/2" break-over bar. Back the the car, we suddenly realized the 1/2" drive is in the middle of each socket so there are two sizes for each. But this is too far from the 1/2" drive of the break-over bar ... and I had no extension. Josh ran back to Sears and returned with the 4" extension. While he was gone, I used my cordless drill and bits to drill out the base on one side of the rounded and mostly broken lug nut. But we could not get it to budge even though we'd soaked it with WD-40 hours earlier. So we looked at the other one that had a 'loose' turning: It looked like it had faces but nothing we tried could get purchase. It would turn but not unscrew! I pointed out the Josh that the first lug nut revealed a metal cover over the actual lug nut. So Josh took the cold chisel and quickly removed the metal cover: So suddenly it became clear . . . WHAT A CRAPPY DESIGN!!! The rounded lug nut was turned too hard so the metal cap/cover simply rounded the internal and external faces. It converted the lug nut into more of an old-style rivet that would not come off by normal means. Realizing he'd screwed up the first lug nut, the tire tech tried to be a little more gentle with the next lug nut and just loosened it so it would rotate without gripping the actual, mechanical nut. Finally the last two lug nuts were put on right which we could remove. Using the lug nut removal sockets and 2 lb sledge, Josh hammered them on and with the extension and break-over, got the top one out. Using the same experimental technique on the other lug nut, he got it to come off too! The now damaged wheel (holes and tool marks) and tire were finally off and the full size spare put on with the two remaining lug nuts. I went to Auto Zone and got two more Toyota style replacements for $9.00. So here are the leftover lug nuts: You can see the holes that were drilled in the base to weaken the nut. LESSONS LEARNED Know the torque limit of the lug nuts and calling the shop manager over, explain the if the lug nuts are over tightened and damaged, you will be bringing the receipt and notes about our conversation in the settlement suit. The torque limits are in the Owner's Manual . . . show it to him and insist a note added to the work order. With a damaged nut, use a 1/2" or smaller, cold chisel and 2 lb sledge hammer to "peel" the outer shell. Spray WD-40 and let it sit (say lunch or break) Use the lug nut removal socket(s) and the 2 lb sledge to pound the removal socket onto the damaged nut. Do not be shy or gentle. Apply torque (use right hand rule, fingers curl in rotation and thumb points to direction.) Find the receipt and visit the shop with all damaged parts and ask,"What shall we do next?" I find no practical use of the external metal cap. It can hide damage and interferes with diagnosis and repair. Note that the alloy wheels require a substantial, flat washer which the Toyota lug nut provides. The Auto Zone 'bingo pack' lug nuts are tapered for use with a steel wheel. DO NOT USE!!!! The soft alloy wheel will soon deform, loosening the nut and the wheel comes off. FYI, nothing was cross threaded. Just a lazy tire tech who used too much torque that twisted the exterior metal cap. Given the cost of making it, some nut screwed up. Bob Wilson
You have reminded me that I recently had tires changed at a shop, and I haven't yet taken my torque wrench to check their work.... -Chap
Last time I got tires I brought in the rims loose (time it with snow tire install/removal). In the next few days: doing that again. Think I've got a justification now. I have seen Costco employees hand-torque them. But no star pattern, just around the circle. Oh, well: one out of two, better than nothing. And, any time a body shop has installed a wheel, the next time i remove it, it's holy hell time! Never got into trouble like Bob though. That is terrible!
A national chain tire shop who flies blimps once managed to break off multiple studs while doing a simple tire balancing/rotation job on our car. Took them hours to bring in replacement studs and wheel locks to replace the ones they damaged using their impact wrench.
Is WD-40 a useful choice for this? On the farm, dad had some other form of penetrating oil labeled specifically for breaking free rusted threads. Spray it on, let it sit a while, tap the nut or bolt multiple times with a hammer to help loosen the rust and help the oil penetrate deeper. But I still snapped two rusted lugs off a wagon when trying to change a wheel.
WD-40 was handy and I don't have a preference for one over the other. We normally have both WD-40 and "3-in-1" oil at the house and this time I just grabbed the WD-40. It smells 'less bad' than 3-in-1 oil and easier to get into tight spaces. I could not see any evidence of rust even after removal. It may be the metal cover over the mechanical lug nut is an effort to avoid moisture and rust on the bolt. The alloy wheels and steel parts would be subject to galvanic action so keeping things dry might justify the metal cover. Just the torque is important to avoid the mechanical issues. BTW, I really appreciate the curb sensors on our BMW i3-REX. Something like this on the Prius might have avoided the SO driving issue that blew-out the tire and led to discovery of the bunged up lug nuts. Bob Wilson
+1 You don't get to pick who you fall in love with.... +1 Big Phone uses a different flavor, but it works. I drive trucks (Prius is a work car) and my CFO has a crossover whose builders tend to have 'real nuts.' Note to self: Verify this later with the CFO's car!! I used to be pretty anal about hand torqueing lug nuts after somebody else touched my car, but that was when I drove sports cars and lived in the frozen North. I was also an active participant in the Great Anti-Seize Wars back in the day...but I now live where humans can survive without snow plows and fireplace inserts, so I let the young'uns slap the hide off of each other over that one. Lately time, sloth, and an excellent record for consistency down at the big box store have dulled my motivations to double check the nuts. I watched them at first, but they seem to use a system of checks and double checks to make sure that nobody limps away on improperly mounted tires. One of the few advantages of living in a country where there are more lawyers than doctors and teachers. People always deride those color-coded torque sticks that you see the tire slingers use, but they are generally even more consistent than the Mk-1, Mod-0 torque wrench, presuming of course that both are used correctly. I always (sometimes) give the nuts a gentle tug with a cheater wrench a few days after to make sure that everything is OK....but lately I've even been lax even about that. One of the (many) advantages about driving trucks and spending all that extra money on gas is that they don't have paper-thin rotors to warp and generally speaking they use plain old ordinary steel wheels with 6-8 lugs. When my trucks go to the automotive equivalent of Valhalla, my intentions are to replace each in turn with as fuel efficient a car as I can afford that is capable of towing 1500#, and I'll probably have to (initially) go back to being a little more anal about these things, but for right now, that dog isn't barking.
Keep an eye on the brakes. Overtorquing the lugnuts might result in damage to the rotors. There are several products out there, and straight turpentine was once sold as a penetrating oil. I have a can of Liquid Wrench, and the only notable difference from WD-40 is that the dried residue isn't flammable if you think you might need to pull out a torch for loosening the offending fastener. Freezing it might also help. If you have canned air cleaning a computer, just turn the can upside down instead picking up a speciality spray.
I have a quart size kerosene bottle, got it for cleaning motorcycle chains about 30 years ago, with just a few spoonfuls still rattling 'round the bottom. I was looking to buy another quart; seems like everyone's selling enormous containers only: 5 gallon or so??
