Anyone have issues with getting your brake rotors turned?

sheltonfilms · #1 01-02-2016, 11:45 PM

Had to get one of my rotors turned today to get a big valley out. Measure the rotor thickness at the valley and it was at 1.01" with the minimum spec being 0.9646 inches. So plenty of meat left to turn out.

Took it to O'reilys and had them turned and put them on my truck.

I've started the habit of checking runout and thickness variation on rotors. Well it finally paid off as I check runout on this freshly turned rotor and it had a runout of 0.010! Good range is like 0.002-0.003 max. 0.010 would be instant pedal pulse. Hell I could the sudden resistance when I turned the rotor by hand with the caliper on.

I have a 2wd so my hub is integrated into the rotor (which also means i can't index the rotor). I wanted to make sure my rotor was on the spindle right and the bearings were ok so I dialed the rotor hub surface and had a runout of 0.001.

Conclusion, guy at O'reillys didn't have the rotor seated correctly on the arbor.

Took the rotor back to O'reillys (first guy wasn't there) and told a new guy whats up. Didn't believe me at first so good thing I showed him a video of the runout. After one look, he said well lets go turn it again for you and get this fixed.

As soon as we put it on you could look closely and see the wobble in the rotor surface by looking at the other edge as it spins.

We got everything in the lathe and I brought my dial indicator just to make sure. In the lathe the hub and rotor runout was the same.

I think what happened is that the previous guy used taper blocks on both sides of the rotor. We tried this and it sometimes it would set right sometimes it wouldn't.

But when we add the big cup to the front so that it goes around the studs and pushes on the hub face instead of the bearing races there wasn't really a way to have it sit funny.

Moral of the story. Get your self a dial indicator and check the rotors you have turned. A really good mechanic does this.

GSF1200S · #2 01-03-2016, 01:29 PM

Quote:

Originally Posted by sheltonfilms

Had to get one of my rotors turned today to get a big valley out. Measure the rotor thickness at the valley and it was at 1.01" with the minimum spec being 0.9646 inches. So plenty of meat left to turn out.

Took it to O'reilys and had them turned and put them on my truck.

I've started the habit of checking runout and thickness variation on rotors. Well it finally paid off as I check runout on this freshly turned rotor and it had a runout of 0.010! Good range is like 0.002-0.003 max. 0.010 would be instant pedal pulse. Hell I could the sudden resistance when I turned the rotor by hand with the caliper on.

I have a 2wd so my hub is integrated into the rotor (which also means i can't index the rotor). I wanted to make sure my rotor was on the spindle right and the bearings were ok so I dialed the rotor hub surface and had a runout of 0.001.

Conclusion, guy at O'reillys didn't have the rotor seated correctly on the arbor.

Took the rotor back to O'reillys (first guy wasn't there) and told a new guy whats up. Didn't believe me at first so good thing I showed him a video of the runout. After one look, he said well lets go turn it again for you and get this fixed.

As soon as we put it on you could look closely and see the wobble in the rotor surface by looking at the other edge as it spins.

We got everything in the lathe and I brought my dial indicator just to make sure. In the lathe the hub and rotor runout was the same.

I think what happened is that the previous guy used taper blocks on both sides of the rotor. We tried this and it sometimes it would set right sometimes it wouldn't.

But when we add the big cup to the front so that it goes around the studs and pushes on the hub face instead of the bearing races there wasn't really a way to have it sit funny.

Moral of the story. Get your self a dial indicator and check the rotors you have turned. A really good mechanic does this.

I couldnt find a parts house that would actually turn my front rotors. "Sorry, your rotors dont fit our machine."

agg1337 · #3 01-04-2016, 07:17 PM

I had to buy new. I asked about getting some turned and I got the same reaction from Autozone, Oreileys, and Advanced Auto. "we don't do that and good luck finding anywhere who does."

NoPower · #4 01-05-2016, 06:14 AM

It seems now days it's cheeper to buy new than the cost of turning. just my 2 cents.

Jeff_Birt · #5 01-05-2016, 09:35 AM

Quote:

Originally Posted by NoPower

It seems now days it's cheeper to buy new than the cost of turning. just my 2 cents.

I don't think so. Looking at O'Riellys they want $50~$60 for each rotor for my 2011 Ranger. I could get all four of them turned there for less than the price of one rotor.

I suspect the biggest issue with places turning rotors is them not being able to find employees with enough common sense to know how to use the brake lathe.

ranger024x4 · #6 01-05-2016, 09:50 AM

I wouldn't waste my time turning rotors, makes it easier to warp in the future.

----------

Quote:

Originally Posted by Jeff_Birt

I don't think so. Looking at O'Riellys they want $50~$60 for each rotor for my 2011 Ranger. I could get all four of them turned there for less than the price of one rotor.

I suspect the biggest issue with places turning rotors is them not being able to find employees with enough common sense to know how to use the brake lathe.

just checked rock auto...cheapest 4x4 front rotor for an 03 ranger (which is what I had) is 10 per rotor, motorcraft is 45 per.

SB03Ranger · #7 01-05-2016, 10:32 AM

look around. Advance always has coupons and rock auto is super cheap. Its better to just buy new ones than turn them.

cowboybilly9mile · #8 01-05-2016, 10:43 AM

Quote:

Originally Posted by sheltonfilms

Had to get one of my rotors turned today to get a big valley out. Measure the rotor thickness at the valley and it was at 1.01" with the minimum spec being 0.9646 inches. So plenty of meat left to turn out.

Took it to O'reilys and had them turned and put them on my truck.

I've started the habit of checking runout and thickness variation on rotors. Well it finally paid off as I check runout on this freshly turned rotor and it had a runout of 0.010! Good range is like 0.002-0.003 max. 0.010 would be instant pedal pulse. Hell I could the sudden resistance when I turned the rotor by hand with the caliper on.

I have a 2wd so my hub is integrated into the rotor (which also means i can't index the rotor). I wanted to make sure my rotor was on the spindle right and the bearings were ok so I dialed the rotor hub surface and had a runout of 0.001.

Conclusion, guy at O'reillys didn't have the rotor seated correctly on the arbor.

Took the rotor back to O'reillys (first guy wasn't there) and told a new guy whats up. Didn't believe me at first so good thing I showed him a video of the runout. After one look, he said well lets go turn it again for you and get this fixed.

As soon as we put it on you could look closely and see the wobble in the rotor surface by looking at the other edge as it spins.

We got everything in the lathe and I brought my dial indicator just to make sure. In the lathe the hub and rotor runout was the same.

I think what happened is that the previous guy used taper blocks on both sides of the rotor. We tried this and it sometimes it would set right sometimes it wouldn't.

But when we add the big cup to the front so that it goes around the studs and pushes on the hub face instead of the bearing races there wasn't really a way to have it sit funny.

Moral of the story. Get your self a dial indicator and check the rotors you have turned. A really good mechanic does this.

I'm biased as to using Motorcraft rotors as opposed to buying some cheapo knock offs made in china, so I always turn mine. And I too, measure both runout and thickness before and after turning, always good to check and verify. But remember the other day in Bob C's speedometer thread, where both you and I mentioned that he take talk to to a good local shop? This is what I do, for the same price as O'Reillys, and the work is done by a guy that's been around the block over and over and over.

Jeff_Birt · #9 01-05-2016, 12:35 PM

Quote:

Originally Posted by ranger024x4

I wouldn't waste my time turning rotors, makes it easier to warp in the future.

----------

just checked rock auto...cheapest 4x4 front rotor for an 03 ranger (which is what I had) is 10 per rotor, motorcraft is 45 per.

You can use your $10 rotors, my life is worth more than that so I'm going to buy a good quality part.

As far as warping, warping is caused by heat. If you abuse your brakes enough to cause warping you are going to warp them no matter what. How do you think the $10 made in China rotors will compare to a turned OEM rotor as far as warping? if you are staying within the manufactures spec on minimum thickness then you have nothing to worry about. In the last 30 years I have had ZERO problems from turned rotors/drums.

cowboybilly9mile · #10 01-05-2016, 01:38 PM

Quote:

Originally Posted by Jeff_Birt

You can use your $10 rotors, my life is worth more than that so I'm going to buy a good quality part.

Something about rotors from china and seeing how some of these cheap rotors have developed cracks around the wheel stud holes in them really doesn't inspire much confidence in reliability and safety does it......

Quote:

Originally Posted by Jeff_Birt

As far as warping, warping is caused by heat. If you abuse your brakes enough to cause warping you are going to warp them no matter what.

Same goes for people who get their brakes good and hot and then drive through deep puddles.

Quote:

Originally Posted by Jeff_Birt

if you are staying within the manufactures spec on minimum thickness then you have nothing to worry about. In the last 30 years I have had ZERO problems from turned rotors/drums.

Amen. Considering the mass of cast iron in a rotor, removing 4.5% of the thickness on just the wear surface itself is hardly a drop in bucket. A driver who warps a rotor turned within spec would also have warped a new, unturned rotor, either due to bad or luck, negligence or a willful act of using good common sense (deliberate abuse).

ranger024x4 · #11 01-05-2016, 01:56 PM

Quote:

Originally Posted by Jeff_Birt

You can use your $10 rotors, my life is worth more than that so I'm going to buy a good quality part.

As far as warping, warping is caused by heat. If you abuse your brakes enough to cause warping you are going to warp them no matter what. How do you think the $10 made in China rotors will compare to a turned OEM rotor as far as warping? if you are staying within the manufactures spec on minimum thickness then you have nothing to worry about. In the last 30 years I have had ZERO problems from turned rotors/drums.

my 10 dollar rotors? GTFO. I only use motorcraft/oem spec replacement parts on my shit, just giving an example. Clearly you missed the motorcraft part price IN THE SAME QUOTE.

sorry, you can argue until your face turns blue but me personally would never turn rotors on an suv/truck. I've seen it time and time again people get come backs for pulsation a few weeks after turning rotors (yes still in spec). Try turning rotors in a 09-14 f150. I bet they will warp the first time you come off a highway.

mms1361 · #12 01-05-2016, 02:16 PM

My neighbor purchased new store brand rotors for his 4x4 f150 to make his brake job easier by just swapping. They were ~significantly~ thinner than his unturned oem rotora. After turning his oem rotors they were still thicker than the new ones.

I see the opposite here and say a thinner newer rotor will be more prone to warping than a turned oem rotor. Of course you can only turn your oem rotors before theyre not within spec though. Personally i just turned mi mine as well but when the time comes theyll be replaced with motorcraft units when replacing them.

As far as cost goes i dont see how its any cheaper unless youre like literally buying crap off china. Even the store brands are like two to three times the cost of turning. I went with a local guy myself $10 but oreillys does them for $12. Oreillys and (some) napa stores are the only ones left in the industry that still offer the service in my region.