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Rotor question


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Anybody know what the front rotor runout spec is for the dodge journey? (2016 SXT 3.6L). Rotor runout is when you attach a dial with a needle against the rotor and spin the rotor and it shows any warpage present in the rotor. Measured in mm or thousands of an inch. Most manufacturers, the spec is between 0.001 and 0.003 inches. Called the dealership and they said 0.007 which seems wrong IMO as that much warpage would for sure be felt in the steering wheel while driving. 

 

Searched online but couldn't find anything. 

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I already replaced them. What's happening is i'm getting a pulsating in the steering wheel on the highway. Tires are already balanced and even rotated to confirm not the tires. Engine mounts are good. Next I want to inspect the rotor runout. If the runout is out of spec that means a) my new aftermarket rotors are out of spec (not uncommon),  or b)the wheel bearing is starting to warp, which also happens.  If the runout is fine, i'll next look into the cv axles which also can cause pulsating when they begin to fail. I already replaced the tierods, balljoints, stab links, stab bar bushings, strut assembly, rotors, pads. Can only be a few things left, such as the cv axles, or lower control arms. If i still can't find it, then f*ck it, i'll trade it in I guess lol

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I think 7 thou is the rotor and wheel bearing play added together.  Seems reasonable.

If rotors are warped they pulse when brake pedal is applied during high speed stopping.

 

Tires can be balanced ok but if belts are crossing internally you can still get pulsing etc.

Does it do the same thing with your winter tires? Can you get another set of tires on car to test this theory.

 

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when you rotate them make sure both front to rear, i had a similar problem with my brand new journey, dealer kept saying the tires were balanced and no problem, i kept moving one tire at aa time till the problem went away and then marked the tire took it back to the dealership and explained what i did they checked it out and then replaced the tire no more problems after that,,,and these were brand new tires with less than couple hundred miles on them

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Hrmmm I've never heard of that before. I've always just followed the proper rotation procedure of cross front to back and back straight to front. But for today's test I'll just go front straight to back and I'll know right away if that made a difference. This is a tought one because the pulsating comes and goes but when it does come, it's always at highway speed.

Edited by Shawn855
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Quick question: is it normal to torque the tire to spec while it's in the air, then lower the vehicle and then I double check the torque and it's still off by a bit? (Having to tighten them a bit more when the vehicle is on the ground ).

 

I'm noticing on the driver side it seems to be the case. Every other tire I torque in the air to spec, lower the car and check the torque and it's still perfect. But the driver side always "loosens" when I lower he vehicle. It doesn't keep the torque spec when on the ground. 

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Okay done and done. Rotated the tires, cleaned the rust off the wheel hubs, and inner parts of the rims, and torqued wheels in star pattern at 70 ft-lbs and then 100 ft-lbs. Still no difference. Dial indicator tool arriving this week to check the lateral runout of the rotors to ensure they are not out of spec. Dodge spec is 0.0078 inches btw. If that is within spec, then that leaves alignment (didn't get professional alignment done so far) or bad wheel balance done (I've seen a few threads so far about a few bad wheel balances happening ). Will keep yous updated to help others. 

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Slightly warped rotors most likely. When it gets worse you will feel through brake pedal as well. Warped fronts tend to be magnified through steering.

 

No one just removes rotors and machines them now. New rotors will be needed. The shudder accelerates pad wear and they will gradually warp more.  Getting close to needing new rotors and pads soon.

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Minor update. I put my dial to the rotor to check for lateral runout. My rotors are both measuring 0.0024 inches. I thought the dodge spec was 0.0078. I was wrong, it's actually 0.00078. So I'm thinking perhaps this is causing some vibrations. If it were the cause, wouldn't I also be experiencing vibrations when braking? When I brake it's smooth. 

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Yeah Im doing the exact perfect method of torquing my lug nuts but I have suspected that perhaps my torque wrench could be faulty and not torquing to the correct 100 ft-lbs. I'll borrow a friend's torque wrench and see.

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You would feel vibration if rotor run out is too much when applying pedal.

Torque wrenches can go out of range but can be recalibrated fairly easily; remove cap on end of handle there’s adjustment.

Important to store them at the lowest setting, not leave them at a high setting.

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Definitely always store it on lowest setting. Here's a question to make you think: Does storage temperature matter when storing the torque wrench? Since heat makes things more maleable, would that affect the spring in the torque wrench? More heat = spring easier to move = easier to hit 100 ft-lbs when spring is hot compared to cold. ;);) 

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That’s why torque settings have a plus minus. Sometimes on high settings like axle nuts, it’s 25 pds range.

Its hard to have exact setting, even lube on threads creates a variance. 
When I built aircraft decades ago (where you signed your initials along with inspector on certain completed jobs) the torque wrenches were calibrated once a week in the tool crib by instrumentation Tec’s.

 

Harbour Freight/Princess Auto versus Snap On or Starret or Mitotoyo, not the same confidence level.

Aluminum rims always need a 50 mile retorque; few heat cycles and aluminum creates potential variance.

 

5 hours ago, Shawn855 said:

Definitely always store it on lowest setting. Here's a question to make you think: Does storage temperature matter when storing the torque wrench? Since heat makes things more maleable, would that affect the spring in the torque wrench? More heat = spring easier to move = easier to hit 100 ft-lbs when spring is hot compared to cold. ;);) 

 

Edited by John/Horace
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11 hours ago, Shawn855 said:

i'm going to be so pissed if all of this mess was caused by a bad wheel balance. 

This was all I kept thinking after reading through this entire thread. Slight vibration, every once in a while (probably at a certain speed) usually points to this. Happened with my old Ford and the guy said... oh, one weight fell off. Yeah, ok. 

Let us know...

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  • 3 weeks later...

Vehicle aligned, and wheel balance checked and it's fine. Vibration still there. Noticed the rear upper control arms are finished so could not align rear. MIGHT be cause of vibration felt in foot anyways....since when driving on the highway, you can see the rear seats vibrate/moving around so i'm guessing the rear alignment/control arms are pretty bad. Parts are ordered so I'll replace that this week, then get a roadforce wheel balance to completely rule out bad tires. If that doesn't fix it, then cv axles. If that doesn't fix it, then control arms. If that doesn't fix it i'm trading it in.

Edited by Shawn855
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I retorqued every bolt last week and everything was in spec. I also had 2 mechanics look at it and they both said everything is tight in the front end. (Again, the rear has upper control arms that are in need of replacement). 

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