Front Brake Rotors

[Automender12345]

I am actually impressed with the tire installation at Walmart. First they used a gray torque stick to impact tighten the lugnuts. I have a similar stick I use which is calibrated to 100FT-lbs. They then took the car for a short trip around the parking lot and pulled back in the garage. Then the manager took a torque wrench and checked every lugut and signed off the paper work. Thats better than I do because they have an independent check of the torque. I have never warped a rotor and if you look at the cross section of a rotor the part that actually sees the torque is a thin 1/8 inch thick piece of steel connected to a conical shape of steel. There is no way you will warp the conical part of the rotor by uneven torque. You would have to warp the wheel hub as well which is near impossible. Maybe the old style rotor that actually had a bearing in the rotor and the studs where part of the rotor, but not the new rotors. If anything is if the rotor is not flat to the hub and you tighten it you maybe able to distort it.

[98SilverSable]

Originally Posted by mjhpadi

I am surprised that you've never heard of this. Well, not this specifically but years ago (and it has been re-enforced several dozen times that lugnuts should always be torqued with a torque wrench to prevent them from warping due to uneven tightening....not sure if uneven tightening is a large problem, but we have not experienced any warped rotors since I've started using a torque wrench on the lug nuts and checking them periodical. There must be some reason for the manufacturers to put torque specs on the lug nuts....

It's just one issue that we've never dealt with

Originally Posted by sfhess

Last time I bought tires for my Fusion three different guys warned me that my lug nuts were so beat up that I might not be able to remove them in the field if I had a flat tire. I told them to stop beating the crap out of the nuts with their zip guns.

Beat up lug nuts on the Fusion and other Ford models are inevitable. The actual lug nut is smaller (like your basic steel wheel lug nut), and the chrome portion is just a thin, hollow aluminum cap that is crimped on and there for looks only. Over time they will get bent and twisted out of shape no matter what tool you use.

[Automender12345]

With the Wal-Mart "techs", who knows what they did. Those guys are just idiots off the street or probably shoppers they just handed applications to. You should NEVER go to Wal-Mart for auto services. I work at a Ford dealership, where we don't intentionally do things so people have to spend more money and our guys are certified and know how to fix a car.

My experience with buying a 2001 taurus from a ford dealer two years ago is the worst I ever had. They did a safety check and replaced the front springs. The car made a lot of noise breaking but they found nothing wrong. I check the car over myself and found a frozen and boot deteroirated rear driver side brake cylinder and a front passenger side caliper slide pin that were frozen. The driver side strut bolts were just finger tight and finally the oil filter (Motorcraft) started leaking a week later. I was able to turn it a half a turn and it stopped leaking. That was from a certified shop and they did nothing when I brought it up to the shop manager. A good mechanic is a good mechanic no matter where they work. I found at least one bad one maybe two at a Ford dealer.

[Intercept]

@mjhpadi my point exactly,,,,,,,, TQ, then Check TQ.....often, i do !

[Intercept]

The point is !! 1. Follow your vehicles manual, if it it says to torque,
DO IT, they just dont print Tq. specs for s...s and
giggles !!

2. Just because some auto mechanics are " Certified "
Auto Technician's,, does not mean that they know
everything there is about every vehicle made ! It
means they have met certain guidelines for the type
of certification they are seeking !! These individuals
are taught a working knowledge of a basic/common
vehicle ! Be it a car, truck, gasoline engine, or diesel
engine. ( I was a helicopter mechanic for 11yrs in
the U.S. Army and was taught a " General working
knowledge of a basic helicopter, it's systems, sub
systems, and basic flight characteristics ! Then was
presented an exam to complete and pass ! Then i
advanced to a course of insruction of a specific model
of helicopter.

3. Does this mean i know everything about helicopters,
or automobiles ? By no means it does not !!!

4. Every individual is different in many ways, some take
pride in their work, and some don't !! Some have
different learning capacities, and then there are the
ones who are there for the money and don't give a
**** about any ones safety !! Sad but true !!!!

5. By no means do i claim to be a professional,or perfect.

6. *But if my vehicle drives fine on my way to have my
tires rotated, then i get back in it to drive it home
and have this violent shaking when i apply the
brakes while driving home then something is
definitely wrong. COINCIDENCE ? ?

7. When i got home i immediately checked out the car
Upon checking my rotors for trueness..(which
were not even close to being true), I installed new
rotors, took it for a "test" drive which in turn
made the car brake even better than before, and
also corrected the violent front end shaking !!!

8. Just saying, but seems to me that rotors can warp.
I am just trying to figure out what was causing this
( because it's my life at stake and possibly others )
I wont accept a " He said, she said, B.S. answer "
on this one at all !! If you know you are right tell
me where i can find the information at and show me!

" Anyone who takes pride in the work they do, will
admit they don't know, hit the books, better
themselves in the process, find the CORRECT
answer, and pass it on to others to read and learn "

[Intercept]

Originally Posted by Automender12345

My experience with buying a 2001 taurus from a ford dealer two years ago is the worst I ever had. They did a safety check and replaced the front springs. The car made a lot of noise breaking but they found nothing wrong. I check the car over myself and found a frozen and boot deteroirated rear driver side brake cylinder and a front passenger side caliper slide pin that were frozen. The driver side strut bolts were just finger tight and finally the oil filter (Motorcraft) started leaking a week later. I was able to turn it a half a turn and it stopped leaking. That was from a certified shop and they did nothing when I brought it up to the shop manager. A good mechanic is a good mechanic no matter where they work. I found at least one bad one maybe two at a Ford dealer.

" A good mechanic is one that will also suck his pride up and admit he does'nt know the answer, then goes and find's the correct answer "

[Automender12345]

If you use logic, look at it this way. I have two flat pieces of steel which are held together by five bolts of uneven torque. What warps, the rotor plate or the hub, or both and the rim of the wheel. I am saying neither but, if one warps the other has to warp. If the latter is correct then if you install a new rotor it will rewarp as soon as you tighten to a warped hub. We all know that never happens right, so what warps when you unevenly torque the lugnuts. There is no way to warp a rotor without warping the hub unless one thing happens. Someone doesn't install the rotor retaining washers on the studs. The rotor shifts when the tire is off and rust falls between the two surfaces. No matter how even the torque is on the studs you will bend the rotor plate to the straight hub. 1/8 steel will always bend to mate up to the 1/4 hub plate. Even if it isn't warped the rotor runout from the uneven mating surfaces will cause pulsing. My guess in the case of tire installation is it is from not having something to keep the rotor from shifting, corrosion and uneven mating surfaces not uneven torque.

Also making sure the lugnuts are clean is as important as the actual torque since the majority of torque value is used to overcome friction. The difference in friction will significantly make a difference in the stud preload and joint preload is what joint reliability is all about.

Try torquing heads with a piece of rust between the block and head, guaranteed warped head and gasket failure.

[Intercept]

hub/bearing assy. was replaced 7months prior to that, mating services were cleaned, to include wheel studs.
everytime wnen i rotate tires i inspect the "exposed" parts, when the wheels are off, to include tire/wheel.
Again upon reassembly, i always take a wire brush and clean my wheel lug threads and wheel/rotor mating surfaces.
High temperature, stress, weight, tq pattern .....could be a factor,,,, but i don't know !
But it is not because i tend to drive with care, avoiding pot holes, slowing down in turns, situational awareness, ie: anticipate my stops, and the car slow its own self down,,,,,,,,...... except for an occassional quik stop on a yellow light.
Where can you point me in the right direction, to verify this ??? Or what is this based upon, your opinion, someone elses, or a publication, TSB, etc... I have looked it up everywhere online, and have gotten the same answer everytime, 7-8 diffferent sites..... but who is to say they are even correct ?

[intimidator]

Originally Posted by Intercept

@breeves yeah i'm a little OCD when it comes to torqueing wheels and other certain items. I was a CH47D "Chinook" helicopter crew member for 11yrs and 90% of our bolts and such are safety wired to where they wont come loose during flight. hmmmmm got me thinking, i think i'll go out tommorrow and do some safety wiring......... nah ! Thats way out there OCD........lol

lol...I had to say something....I'm ex-Navy also...I safety wire my oil filter on my truck every time

[Automender12345]

I safety wired my tires to the rims but I realized it seem to cause more flat tires. My opinion was dilling holes in the sidewalls shortened the life of the tires.


What I would do if I were you "Intercept" is to unevenly torque one wheel's luguts. Not enough to cause the wheel to fall off but what you think Walmart did. I won't even use the start pattern to tighten them and not step torque them either. You know how bad they were because you removed the lugnuts. Report back to the forum on results after driving it, as you said just a few miles. For no more than $35 ( cost of a new rotor) you can solve the great mystery in your life.

My untested theory is that there is no way you can warp rotors in a few miles if the mating surfaces are as clean as you keep yours and the rotors are seated properly. From what I read, it is the uneven rotor wear from excessive runout is what causes pulsing. You actually need bearing and rotor runout to spread the pads open after you release the brakes. Without runout the pads would skim the surface of the rotor and cause overheating. Think about it, drums have retract springs but calipers don't. I could be all wrong and would be excited to hear the results.