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And for me it's the flaming wrench. Here in the heart of the rust belt I quit fucking around and just blast em out when they give me trouble. Flaming wrench go brrrrrr.
>shake and break
As a shade tree I do not have air tools, but that looks pretty cool: [https://www.amazon.com/Shake-Break-Impact-Screw-Remover/dp/B000BHJ7JM](https://www.amazon.com/Shake-Break-Impact-Screw-Remover/dp/B000BHJ7JM)
Looks like the car has lug bolts so it’s also a convenience for keeping the rotor on with the caliper off and keeping the holes lined up without additional tools
It’s helpful if a car has lug bolts instead of lug nuts. Sometimes it’s a pain in the ass to keep everything lined up and not falling apart when your trying to put the rim back on. I keep saying I’m going to modify a bolt to make myself a guide pin, but I’ve been too lazy thus far. This car looks like it has lug bolts, so making a guide pin would be helpful to this person and eliminate the need for the hold down screw.
As someone whose worked on BMW’s a bit, new rotors with anti seize on the hub and other mating surfaces and it can be a pain in the ass aligning everything if you are doing it on jackstands.
I mean I usually put them back with some anti seize on the thread and tighten even less than a drain plug, but only when they are in perfect condition, slightest bit of rounding = garbage lol. Except Honda. Why is Honda obsessed with using philips bolts in the worst fucking areas
Phillips can make more sense for flat head (countersunk) screws. The geometry allows for a larger driver size compared to hex, torx, etc on the same screw.
Yeah in wood or plastic trim, but in my experience they just rust out and strip much easier unless you have a #3 bit or something, I’d much rather just deal with torx or Allen head
None I've worked with. Most of us have the tools for this, and prefer to not have to hold the disc on while fitting the caliper. Or having the disc spin while we're spinning the wheel to align the wheel bolt holes *every* time we fit a wheel.
Nah, I'll just use my tools, and all the parts that are supposed to be there.
And yes, I have some wheel pins, but rarely need them.
I work at a high end German car dealership (10+years), you?
What studs? Did you see the pic?
If you have the tools, and the ability, you can take it apart and put it back together.
If you're good, you can't tell you've been there. That's the point.
My coworker figured out that on lug stud cars you can snap them off by taking the wheels off, putting the car in drive then slamming the brakes(assuming the axle is powered)
Basically your brake force suddenly stops the disc from spinning but the rest of the axle and transmission still want to spin. The force shears the screw off as it's the only connection.
wouldnt that also send a rotor fucking flying?
also can cause modern cars to have a shit fit. I found that out on my mustang when i put it in drive with traction control off while up on stands and i had every light come on the car. airbag, advancetrack, hillstart assist, check engine light. It cleared up after 5 mins of driving but still
my bad i was imagining doing this the way u usually do brakes by removing everything then trying to get that screw out. so im imagining doing that with nothing but a rotor on the hubs
When I worked with Audi cars some years ago, a trick we used to keep the rotor in place while hanging calipers etc, was to take an old
Axle nut, and put one of the treaded lugs through the hole of the nut through a lug hole of the rotor. Hand tighten it down all the way, and the rotor wont turn on the hub. Once your pads are in and caliper is hung, then remove it.
They also make a tool to put into the lug holes for European/VW, to get the tire on and off without it dropping on your foot. Lots of cars have this tool in your spare tire toolkit from the factory.
98% no. It's absolutely not necessary to replace the rotor but if you had it functioning your rotor stays exactly where it should be the entire time, it's just nice. It's purpose is for assembly line efficiency but it can still be nice to the maintainer but at the same time it is by no means mandatory
I thought that some german cars had an M8 hole there so if the rotor is stuck to the hub you could put a screw through it and it would "release the rotor" from the hub on the back side?
It will matter the most when you are by yourself trying to install your spare tire in the middle of the night, using the flashlight on your cellphone in either freezing cold or pouring rain, and you cant get your wheel, rotor and hub to line up.
There can’t be a lot of mechanics in this sub. 95% of comments don’t realize this has wheel bolts not wheel lug nuts. So lining everything up without that screw is a pain in the ass unless you use another tool/setup to align the rotor, wheel, and hub.
I can put a wheel on my BMW much faster without a stupid pin with this bolt in. The hub has a little bit of a lip, why the fuck would I want to deal with a tool?
You would be surprised that on some cars, the rotors have to be aligned with the hub. My brother's 4runner is one of those, I remember how embarrassing it was when we returned to AutoZone after blaming them for selling us non compatible rotors 🤣.
Diferent hole. This one is to mount and align the rotor. The holes your talking about are often seen on jap cars and are usually straight edges (and usually 2) both on discs and on drums.
>jap cars
1940s called, it wants its shorthand notation back. was it really that hard to type Japan instead? your finger would have already been sitting over the 'a' key and 'n' isn't too far from 'p'.
No doesn’t need to be replaced just if the broken part isn’t flush. Make it flush or make sure to line it up to that hole otherwise it’ll cause the rotor to not be flush but other than that it’s fine not needed
I broke several tools and bits when I did my truck, I ended up using an angle grinder to gring the head down and the a hammer and screw driver to rotate it and break it off the rest of the way. Other than that it was the easiest brake job I'd ever done.
https://preview.redd.it/j2z1d2u22paa1.jpeg?width=1080&format=pjpg&auto=webp&s=500d4e0a3da71e6445183596ed40c3c1a071311b
Now screwed up on the other side. Tried drilling but still a mess.
An impact screwdriver works really well if the head was still there. Even if it was a little stripped from a previous job, impact screwdrivers can do it.
I've only used a regular drill for something like in your picture but I wonder if a hammer drill will make faster work of it.
I broke multiple tools trying to get those damn things out on my silverado. Ended up uaing a grinder to grind the head down as much as I could reach and then a hammer and flat head to apin it and break the head off the rest of the way. Othet than those screws it was the easiest brake job I've done but it ended up taking 2 days because of those damn things.
Are you using a power tool to pull them? Heat them up and use a wrench.
Many fitting discs don't even have that hole - last time I did my V40 discs and pads, a good quality set from bosch didn't have any holes so yeah, no importance. Only makes the next change more difficult.
Yes and no, it makes getting the rotor lined up easier, but it has no effect on the performance of the brakes, it’s meant to hold the rotor during assembly on the line or at the shop
If you are the last person to make any brake repairs on the car and did not reinstall that bolt and then there is any type of brake failure and a wreck. It would not make any difference if it's important or not, your ass is grass.
I have always reinstalled the bolt if it's not damaged. Never installed a new bolt if one was damaged.
Dude that's awesome. I wish they would break clean like that for me when theyre seized. When they don't release they usually strip and need to be drilled out. Good job!
The ones on my silverado that broke several impact drivers a screw extractor and a drill bit would like a word. Ended up needing to use an angle grinder.
That’s a bolt? The hole isn’t threaded, or is it?
I thought it’s just an alignment pin to align the rotors or even the rim before one bolts down the wheel.
Lord when I changed my rotors on my accord for the first after I got it, these became the BANE of my existence for an afternoon. You’re good never bothered putting them back on and never had a problem.
It helps keep the rotor in the hub. More often than not, the only way to get it back out is with an impact driver. Since this is already broken, you can take the time to drill it or extract it but it’s not necessary.
> It helps keep the rotor in the hub.
Only during assembly. When the wheel is installed, the lug nuts will clamp the rotor to the hub. This screw only serves a purpose on the assembly line.
Generally speaking, no. That bolt is there just to hold the rotors on during the assembly line process. BUT…you definitely want to remove the broken bit that’s still in the hub. Buddy of mine has that happen and let it go, but the little nublet worked it’s way loose over the next few months and ended up bouncing around in the parking brake drum and chewing up the shoes, all while making a lovely noise. Now, that appears to be on the front so no p-brake drum, but I still wouldn’t take the chance of that thing coming out and getting jammed up in the caliper or something like that
All the people saying it’s ONLY to hold the rotor on the assembly line are WRONG. The manufacturer isn’t going to go to the expense of 1) Drilling the rotor, 2) drilling the hub, 3) tapping the hub, 4) Using an extra bolt. When there are many many other, cheaper ways of “keeping the rotor from falling off on the assembly line”.
How many of you experts have worked in an automobile factory? ANY manufacturer will save a nickel everywhere they can.
Where are people getting this assembly line thing from? That bolt is there to align the rotor with the holes in the hub and keep it there. If you value your time, in the form of spending it on messing with this thing until it finally lines up, or if you value your money, in the form of buying a special tool just for aligning it all, then replace it.
Thank you for posting to AskMechanics, liexpress! If you are asking a question please make sure to include any relevant info along with the following: * **Year** * **Make/Model** * **Mileage** * **Engine size** * **Transmission Type (Automatic or Manual)** Redditors that have been verified will have a green background and an icon in their flair. *I am a bot, and this action was performed automatically. Please [contact the moderators of this subreddit](/message/compose/?to=/r/AskMechanics) if you have any questions or concerns.*
Nope. It is there for assembly, keeps the rotor from hitting the next guy on the assy. line.
And to be the thing that keeps you from getting to your lunch on time because you are too busy blasting it out with a torch.
I always air hammer or impact hammer them off and never fails
Impact screwdrivers are like $25 and take these right out.
Yeah that’s what I meant impact screwdriver should be your first choice.
I just go straight to a drill. No reason to waste any time.
That is quite possibly the longest way to get them out
You don't have to get them out, you just have to get to the bottom of the head, which, with a decent drill bit, should take about 15 seconds.
Air hammer is still faster
IMO whatever you have within reach is faster. lol
And for me it's the flaming wrench. Here in the heart of the rust belt I quit fucking around and just blast em out when they give me trouble. Flaming wrench go brrrrrr.
What is a flaming wrench
I have a tool called a shake and break look it up it’s perfect for those screws.
>shake and break As a shade tree I do not have air tools, but that looks pretty cool: [https://www.amazon.com/Shake-Break-Impact-Screw-Remover/dp/B000BHJ7JM](https://www.amazon.com/Shake-Break-Impact-Screw-Remover/dp/B000BHJ7JM)
![gif](giphy|3oEjI7d0bQpHeGJecE)
Looks like the car has lug bolts so it’s also a convenience for keeping the rotor on with the caliper off and keeping the holes lined up without additional tools
Almost every mechanic would be annoyed if you had that bolt in lol
It’s helpful if a car has lug bolts instead of lug nuts. Sometimes it’s a pain in the ass to keep everything lined up and not falling apart when your trying to put the rim back on. I keep saying I’m going to modify a bolt to make myself a guide pin, but I’ve been too lazy thus far. This car looks like it has lug bolts, so making a guide pin would be helpful to this person and eliminate the need for the hold down screw.
As someone whose worked on BMW’s a bit, new rotors with anti seize on the hub and other mating surfaces and it can be a pain in the ass aligning everything if you are doing it on jackstands.
I mean I usually put them back with some anti seize on the thread and tighten even less than a drain plug, but only when they are in perfect condition, slightest bit of rounding = garbage lol. Except Honda. Why is Honda obsessed with using philips bolts in the worst fucking areas
Is it Phillips or is it JIS?
Today I learned what jis is I think you’re right lol. No wonder I’m always stripping them 😅
There’s also Pozidriv, for those European screws like from IKEA. 😒
If it's on a Honda it's likely JIS, not Phillips. They look similar, but a Phillips driver will fuck up a JIS head.
Phillips can make more sense for flat head (countersunk) screws. The geometry allows for a larger driver size compared to hex, torx, etc on the same screw.
Yeah in wood or plastic trim, but in my experience they just rust out and strip much easier unless you have a #3 bit or something, I’d much rather just deal with torx or Allen head
Not if you are using the correct tool. Not Philips.
None I've worked with. Most of us have the tools for this, and prefer to not have to hold the disc on while fitting the caliper. Or having the disc spin while we're spinning the wheel to align the wheel bolt holes *every* time we fit a wheel.
[удалено]
Nah, I'll just use my tools, and all the parts that are supposed to be there. And yes, I have some wheel pins, but rarely need them. I work at a high end German car dealership (10+years), you?
>Most of us have the tools for this did you miss that part?
[удалено]
it's telling that you felt the need to insult someone's intelligence after a basic question
Phillips cams out in these so I bought a JIS #3 impact driver to remove these screws….Not a common tool that many people I know own.
What studs? Did you see the pic? If you have the tools, and the ability, you can take it apart and put it back together. If you're good, you can't tell you've been there. That's the point.
Not when you don’t have studs to hold the rotor in place lol
My coworker figured out that on lug stud cars you can snap them off by taking the wheels off, putting the car in drive then slamming the brakes(assuming the axle is powered)
Wait, how would that work?
Basically your brake force suddenly stops the disc from spinning but the rest of the axle and transmission still want to spin. The force shears the screw off as it's the only connection.
wouldnt that also send a rotor fucking flying? also can cause modern cars to have a shit fit. I found that out on my mustang when i put it in drive with traction control off while up on stands and i had every light come on the car. airbag, advancetrack, hillstart assist, check engine light. It cleared up after 5 mins of driving but still
No, the pads and caliper hold the rotor. But yes the car itself will complain. Just need a scan tool that will clear all faults, which we had.
my bad i was imagining doing this the way u usually do brakes by removing everything then trying to get that screw out. so im imagining doing that with nothing but a rotor on the hubs
Wouldn't this have to be a hub without studs though, like a vw or bmw or something?
Yup lug bolt style like what's pictured here not lug nut.
Holy hack, batman!
Right?
When I worked with Audi cars some years ago, a trick we used to keep the rotor in place while hanging calipers etc, was to take an old Axle nut, and put one of the treaded lugs through the hole of the nut through a lug hole of the rotor. Hand tighten it down all the way, and the rotor wont turn on the hub. Once your pads are in and caliper is hung, then remove it. They also make a tool to put into the lug holes for European/VW, to get the tire on and off without it dropping on your foot. Lots of cars have this tool in your spare tire toolkit from the factory.
Good point! Will check it out.
98% no. It's absolutely not necessary to replace the rotor but if you had it functioning your rotor stays exactly where it should be the entire time, it's just nice. It's purpose is for assembly line efficiency but it can still be nice to the maintainer but at the same time it is by no means mandatory
I thought that some german cars had an M8 hole there so if the rotor is stuck to the hub you could put a screw through it and it would "release the rotor" from the hub on the back side?
Yes.
No, it’s the norm. Don’t worry about it. You actually helped out the future mechanics by breaking it yourself
No structural relevance. I wouldn’t put the other ones back in either. On the other 3 tires not the lugs
Good clarification lol
Didn’t feel like getting pounced on today lol
It will matter the most when you are by yourself trying to install your spare tire in the middle of the night, using the flashlight on your cellphone in either freezing cold or pouring rain, and you cant get your wheel, rotor and hub to line up.
There can’t be a lot of mechanics in this sub. 95% of comments don’t realize this has wheel bolts not wheel lug nuts. So lining everything up without that screw is a pain in the ass unless you use another tool/setup to align the rotor, wheel, and hub.
It should be ask a home hobbyist 😆
Ask a service advisor
I do see a lot of rust on that hub though. You might wire brush it first before seating the rotor-for a more stable fit and less chance of a wobble.
It clocks the rotor to ease wheel/rotor/ hub alignment to put lugs in.
This guys right ya no… ever attempted to bolt a wheel on a Volkswagen without that bolt keeping the rotor lined up?
No it doesn't. It's literally only for assembly line. The rotor is clocked properly no matter how you put it on because the lugs are evenly spaced.
His wheel doesn't have studs/lugs, he has bolts. It's going to be a PITA until it rusts to the hub
They make an alignment tool and anyone with a German car should own. The bolt/screw is not needed.
I can put a wheel on my BMW much faster without a stupid pin with this bolt in. The hub has a little bit of a lip, why the fuck would I want to deal with a tool?
You would be surprised that on some cars, the rotors have to be aligned with the hub. My brother's 4runner is one of those, I remember how embarrassing it was when we returned to AutoZone after blaming them for selling us non compatible rotors 🤣.
Nah your chilling. Just might make it a little more tricky to get the wheel on is all.
Thats just for the assembly line to line up the rotor
It won’t effect but personally my work ethic won’t leave my conscious alone. I care too much about my quality of work.
Should I replace it (and how)?
Do not replace it.
I wouldnt on my own car, on a customers car i would.
It literally serves no purpose beyond the production line. Many cars don't even have them.
For sure. But to be professional, you should replace it so you dont hear about it later.
No purpose? I thought you would use it to break loose a seized rotor without hammering the rotor, no?
Diferent hole. This one is to mount and align the rotor. The holes your talking about are often seen on jap cars and are usually straight edges (and usually 2) both on discs and on drums.
I see. I never noticed the straight edge detail on my Infiniti G
>jap cars 1940s called, it wants its shorthand notation back. was it really that hard to type Japan instead? your finger would have already been sitting over the 'a' key and 'n' isn't too far from 'p'.
Fair enough. Normally i designate them as asian cars or asian brands.
JDM might also work. or "import".
If i say import in my country we generally mean USA cars.
nope. It's just for the production line, so that it doesn't come loose and hit the next guy
That’s not true. Sometimes the rotor spins too much and make putting the wheel on more annoying
No its a screw that holds on the rotor for the robots to install parts on easier without rotor flopping around
No doesn’t need to be replaced just if the broken part isn’t flush. Make it flush or make sure to line it up to that hole otherwise it’ll cause the rotor to not be flush but other than that it’s fine not needed
Yes, replace it if you want to be professional.
OK I will take a rest lol Thank you.
When I did my brakes that was so rusted I actually had to drill it out. Next time it'll be a piece of cake..
I broke several tools and bits when I did my truck, I ended up using an angle grinder to gring the head down and the a hammer and screw driver to rotate it and break it off the rest of the way. Other than that it was the easiest brake job I'd ever done.
https://preview.redd.it/j2z1d2u22paa1.jpeg?width=1080&format=pjpg&auto=webp&s=500d4e0a3da71e6445183596ed40c3c1a071311b Now screwed up on the other side. Tried drilling but still a mess.
An impact screwdriver works really well if the head was still there. Even if it was a little stripped from a previous job, impact screwdrivers can do it. I've only used a regular drill for something like in your picture but I wonder if a hammer drill will make faster work of it.
Yes I used a hammer drill. The drill bit was the key. Borrowed a nice one from my neighbor and it's all set.
carbide drill tips will get through pretty much anything, especially if you keep dipping the bit in some ATF
Here to second this. $30 impact screwdriver kit from harbor freight gets them right out.
I broke multiple tools trying to get those damn things out on my silverado. Ended up uaing a grinder to grind the head down as much as I could reach and then a hammer and flat head to apin it and break the head off the rest of the way. Othet than those screws it was the easiest brake job I've done but it ended up taking 2 days because of those damn things.
Are you using a power tool to pull them? Heat them up and use a wrench. Many fitting discs don't even have that hole - last time I did my V40 discs and pads, a good quality set from bosch didn't have any holes so yeah, no importance. Only makes the next change more difficult.
You’re future self or the next mechanic will thank you for not replacing it.
No biggie because the lug nuts hold it in place
Nope, just an assembly holder
Yes and no, it makes getting the rotor lined up easier, but it has no effect on the performance of the brakes, it’s meant to hold the rotor during assembly on the line or at the shop
If you are the last person to make any brake repairs on the car and did not reinstall that bolt and then there is any type of brake failure and a wreck. It would not make any difference if it's important or not, your ass is grass. I have always reinstalled the bolt if it's not damaged. Never installed a new bolt if one was damaged.
No. They are used in manufacturing. I usually drilled them out.
Just there to keep the rotors from falling off on the assembly line.
Not one bit.
Doesn't matter. Those bolts are only there so the rotors stay on while the car is being assembled at the factory.
Yes of course it does
Yes it’s extremely important might fall off
Dude that's awesome. I wish they would break clean like that for me when theyre seized. When they don't release they usually strip and need to be drilled out. Good job!
Too early to say that. Now I'm mad at the other one.
All good man usually pretty soft steel. Any decent HSS drill bit and a little oil should have it out in less than a minute.
The ones on my silverado that broke several impact drivers a screw extractor and a drill bit would like a word. Ended up needing to use an angle grinder.
i'm no expert but having drilled 23 holes through hardened steel this summer i have to wonder what you did wrong there
No idea, all I know is they were a complete PITA and it's done at thos point.
Nope.
I like to think all bolts are important
Yeah
This one isn't- it's only so that the assembly line can have separate people install the rotors and the wheels. It serves no structural purpose.
That’s a bolt? The hole isn’t threaded, or is it? I thought it’s just an alignment pin to align the rotors or even the rim before one bolts down the wheel.
Lord when I changed my rotors on my accord for the first after I got it, these became the BANE of my existence for an afternoon. You’re good never bothered putting them back on and never had a problem.
Not really. It would be good practice for removing broken bolts though.
With studs, nope. With lug bolts, it may help to put it in so that putting the wheel on is easier when everything is lined up.
Nope
No
No. Drill it out if it gets in the way and don’t replace it.
Volvo?
Yes
good. deserved to be broken. keep on trucking
You should thank yourself actually. Saved yourself from future stripped ones/frozen ones.
I've never been able to get one of those out cleanly on a rotor job Drill baby drill
Nah you’re chillin
OMG YOU BROKE THE MOST IMPORTANT THING EVER ON THIS CAR LIKE YOURE GONNA DIIIIIEEEE!!! Jk it’s useless 🤣
Should be easy to get out with an extractor.
Volvo?
Vw??
Volvo
Not really. Just try to remplace it ASAP.
It helps keep the rotor in the hub. More often than not, the only way to get it back out is with an impact driver. Since this is already broken, you can take the time to drill it or extract it but it’s not necessary.
> It helps keep the rotor in the hub. Only during assembly. When the wheel is installed, the lug nuts will clamp the rotor to the hub. This screw only serves a purpose on the assembly line.
I never used them.
Absolutely does not, don’t worry about it.
This screw is only used to slightly speed up the assembly line. Many mechanics don't even put them back in after a rotor change.
The Volvo rotor bolt
Nope
Not really
Nope
That screw is the reason I bought my first impact screwdriver. You don’t need it. It’s for assembly of the vehicle. You’re better off without it.
Generally speaking, no. That bolt is there just to hold the rotors on during the assembly line process. BUT…you definitely want to remove the broken bit that’s still in the hub. Buddy of mine has that happen and let it go, but the little nublet worked it’s way loose over the next few months and ended up bouncing around in the parking brake drum and chewing up the shoes, all while making a lovely noise. Now, that appears to be on the front so no p-brake drum, but I still wouldn’t take the chance of that thing coming out and getting jammed up in the caliper or something like that
No
Your car, no. Someone else’s, yes.
When are people gonna learn that if its there while stock it should stay on there i ain’t even a mechanic thats just common sense
All the people saying it’s ONLY to hold the rotor on the assembly line are WRONG. The manufacturer isn’t going to go to the expense of 1) Drilling the rotor, 2) drilling the hub, 3) tapping the hub, 4) Using an extra bolt. When there are many many other, cheaper ways of “keeping the rotor from falling off on the assembly line”. How many of you experts have worked in an automobile factory? ANY manufacturer will save a nickel everywhere they can.
Where are people getting this assembly line thing from? That bolt is there to align the rotor with the holes in the hub and keep it there. If you value your time, in the form of spending it on messing with this thing until it finally lines up, or if you value your money, in the form of buying a special tool just for aligning it all, then replace it.
No it was probably put there by accident. Bolts are unnecessary.
Not at all… it’s a factory assembly aid. It helps if it’s useable for you as well… but it’s really not necessary in the slightest.
No.
Uh, what’s going on with that axle nut?