Help with clunking after rotor/pad replacement!

[rickprins]

Hey everyone, thanks in advance. I've got a 2014 CX-5 Touring AWD and I just replaced my pads and rotors this past weekend. I've done this before and I'm pretty confident in my ability (though I'm not perfect!) At the same time I also replaced my stock 17's with some 18x8 Mitsu Eclipse wheels that have the same numbers (5x114.3, ET46, 67.1 CB). The issue I'm now having is there is a clunking noise when hitting small bumps and frost heaves (Pure Michigan). My initial thought is that the rims are still "floating" even though the bolts are tight.

Any thoughts? Do I need more "lug centric" lug nuts? I used the OEM Mazda ones.

Pic for reference.

 

[CarpeDiem]

You should be using hub centric wheels or rings. But I’m not convinced that is the cause of the noise, if so you should be getting a bad vibration too. More likely the new wheels/tires are hitting something in the vehicle - what kind of noise do you get when going over big bumps?

Not knowing how you changed the brakes, something there could be rattling (pins, rattle clips) but probably not.

 

[AVC]

If you left off the pad clips, they will rattle in the caliper. If your tires are striking the strut springs or spring mounts, you can duplicate that by opening the driver and passenger doors and use them to leverage to front end up and down, while someone listens.

 

[rickprins]

@CarpeDiem It shouldn't be the hub because the Mitsu wheel specs are a 67.1mm Hub as well - but maybe...?

I try to avoid big bumps!

I think I may just pull them all off and check everything out. Maybe buy some diff log centric nuts (probably should get my wife's input on that ).

 

[rickprins]

If you left off the pad clips, they will rattle in the caliper. If your tires are striking the strut springs or spring mounts, you can duplicate that by opening the driver and passenger doors and use them to leverage to front end up and down, while someone listens.

Should be plenty of room in the wells for new wheels. www.wheel-size.com showed I actually gained a small bit of room.

However - it is interesting that the pads did not come with the V shaped clips. They are Napa Premium (I think mid-grade) ceramic.

 

[rickprins]

I'd like to thank you all - especially @CarpeDiem & @AVC for coming today and participating in Rick's a DumbA$$!

I just remembered that they gave me the correct Mitsubishi lug nuts (same thread/pitch/dia) and they are a Mag Seat with Washer style. I'm pretty sure the problem is the conical Mazda lug nuts are letting the rim "slide" a bit. I'll swap them out tonight and see if that doesn't fix it.

 

[theblooms]

Also, just as an aside, did you wire wheel the the caliper slides clean where the pads ride and apply antisieze? You should have also cleaned the slide pins and applied silicone paste, not grease.

 

[rickprins]

@theblooms Yes I did all of the above for the brakes using silicon paste. Brakes I'm pretty good at. As for the other... let's just say I'll never be the tire guy on a NASCAR Pit Team.

 

[rickprins]

OK, so maybe I'm not the dumbass I think I am... or maybe dumbass me only thinks I'm not a dumbass. Either way I put the correct lug nuts on and I still get the noise.

So for more information (or maybe defining proof of my dumbass-ed-ness) I smoothed out the tabs on the pads with my grinder so they would slide better (along with generous amounts of silicon paste) in the calipers. I had a sticking rear caliper that needed new slide pins so I listened to an old mechanic acquaintance that suggested I smooth out the tabs a bit. Could the noise be the pads rattling in the caliper? I don't think I made them that loose...

Questions/comments/suggestions/prayers/incantations?

 

[theblooms]

Yeah, the "smoothing" out definitely could cause the rattling. It's supposed to be a petty snug fit, not loose at all.

 

[AVC]

Might see if there are stainless caliper clips available, or if there are spring holes in the pad plate, use the seperator springs. Otherwise there's not an elegant or safe way to add material onto the pad tabs to take up the gap and solve the rattle.

 

[DrElectron]

Do you still have the 17s? Try putting them back on and see if the noise goes away. This will help you isolate problem to tires vs. brakes. What is make, model, age of your 18 inch tires? Have you checked for defects such as flat spots, out of round, etc.

 

[rickprins]

So after further research and investigation I think one (or more) of the wheels has a flat spot. I am having it looked at next week. I can't see any discernible flat spots. I'm told from the Honda dealer that the clunking is my shocks. I'll have them look at the shocks as well for a 2nd opinion.