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Discussion Starter · #1 ·
I replaced my wheels a few years ago after I discovered a crack in one of the rims. At the time I wasn't in a good enough financial position to spend the coin on a replacement set. The guy at Discount sold me some Motegi and that was that. Until I got on the highway and the shaking began at speeds from 70 to 75 mph. I went back and complain and they added a set of graphite hubcentric rings. The shaking got a little better but is still there. A year later, I replaced the graphite ones for a stainless pair hoping that the higher quality set would make a difference. No dice.

Other than replacing the rims for ones with 66.6 mm hub bore is there anything else I haven't thought of that could remedy the issue?

Thank you in advance
 

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guess you have had the wheel balanced ? should be little weights stuck on if you have
 

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Discussion Starter · #3 ·
guess you have had the wheel balanced ? should be little weights stuck on if you have
Yes, sir. I’m a bit at a loss. I’ve never had an issue like this before but then any time I’ve done a wheel upgrade it’s been with matching wheels.
 

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cross rotate the wheels and see how the shake follows

about a 12-15Hz vib?

sometimes its just a bead reset (like mine) or a poor tire carcass defect

if the rims are not hub specific you are at the mercy of those silly rings and sometimes those suck

if you can try checking the rim run outs ... dont need a dial indicator just a sharpie and flashlight
 

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Discussion Starter · #5 ·
cross rotate the wheels and see how the shake follows

about a 12-15Hz vib?

sometimes its just a bead reset (like mine) or a poor tire carcass defect

if the rims are not hub specific you are at the mercy of those silly rings and sometimes those suck

if you can try checking the rim run outs ... dont need a dial indicator just a sharpie and flashlight
I can't identify the frequency. It's enough that my 5 yr old son punks me by singing so his voice vibrates.

I've changed the tires at least twice so I feel the bead shouldn't be an issue. I'll take a look at the hubs. The rings seemed to fit snuggly but you never know. And I'll go with a cross rotate and see if that makes a change to the vibration. It's possible there is a minor defect in one of the rims.
 

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I replaced my wheels a few years ago after I discovered a crack in one of the rims. At the time I wasn't in a good enough financial position to spend the coin on a replacement set. The guy at Discount sold me some Motegi and that was that. Until I got on the highway and the shaking began at speeds from 70 to 75 mph. I went back and complain and they added a set of graphite hubcentric rings. The shaking got a little better but is still there. A year later, I replaced the graphite ones for a stainless pair hoping that the higher quality set would make a difference. No dice.

Other than replacing the rims for ones with 66.6 mm hub bore is there anything else I haven't thought of that could remedy the issue?

Thank you in advance
most likely it's either the fitment of the motegi wheel is not for your car, or the installation is not properly done. For example, if the bolt pattern spec is not exactly sized for your car set up, any give in how the bolt rods go onto the wheels , can cause a shimmy.
 

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tape a sharpie to a heavy stool (or rock brick dead cat etc) and check radial and lateral runout

might explain a lot
 

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Discussion Starter · #8 ·
tape a sharpie to a heavy stool (or rock brick dead cat etc) and check radial and lateral runout

might explain a lot
Thank you for the suggestion but would run out be apparent after changing tires? The vibration is the same intensity since the wheels were changed which has gone through two sets of tires. Also, I calculated the frequency at 300 hz.
 

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something does not make sense ... 300hz is too high for a 25” diameter tire

say 60mph or 1mi/min or 5280ft/min or 88ft/sec
1 tire rev 78.5”
88fps or 1056fps means 13.45 rev/sec
so 13~15hz vibration per 1 funny point on a tire at 60~70mph

that would be your kids punked voice rate while driving with that thumping

raise the wheels (one at a time is fine) and yank it around listen / feel for any movement to hunt for bad mechanics

spin the rim lip against the fixed sharpie to check for rim runout both axes ... will show warp (in out) and centering (up down)
 

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get a spectrum analyzer app on your phone if possible

strap phone tight to the center console cup holder areas with some blue tape (be like a microphone)

see what frequencies pop up
 

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could this be a dodgy drive shaft ?
some c43 and c63 cars had that phantom shakey and it was a messed up balance on one shaft

so stupid

for us its either
rim fab error
tire carcass density bug
overall wheel balance (incorrect road force setting)

but if all else checks out ... could be a shaft balance but lets see what the spectrum analyzer says
 

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some c43 and c63 cars had that phantom shakey and it was a messed up balance on one shaft

so stupid

for us its either
rim fab error
tire carcass density bug
overall wheel balance (incorrect road force setting)

but if all else checks out ... could be a shaft balance but lets see what the spectrum analyzer says
But the OP issue was that it happened after he replaced the cracked wheel with the motegi wheel, if I am correct. Hence if it was a shaft balance, would it not happen even before replacement of the wheel?
 

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Maybe the bump that cracked the wheel was hard enough to damage the drive shaft ,maybe even the top mount of the shock, just grabing at straws
 

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Discussion Starter · #15 ·
But the OP issue was that it happened after he replaced the cracked wheel with the motegi wheel, if I am correct. Hence if it was a shaft balance, would it not happen even before replacement of the wheel?
Maybe the bump that cracked the wheel was hard enough to damage the drive shaft ,maybe even the top mount of the shock, just grabing at straws
I found the crack because the tire wouldn’t keep air. I did a manual inspection looking for a nail with soapy water with no results. Discount tire found the cracked rim and the vibration started after I installed new rims and kept the original tires. The vibration was pretty apparent after leaving the store. They installed huncentric rings which reduced the vibration on city streets but once I hit the freeway it was clear it didn’t fix everything. It’ll vibrate between 70-80 mph with 75 being the roughest.

I’m thinking it’s either the lugs or leg bolts since I changed out the hubcentric ring last year to make sure they got the proper size.

Before I do any of that I’m going to cross swap my rims to see what if any change that makes.

Everything online says it’s the rings but I don’t buy that since I changed them out. I’m honestly at the point of saying fuck it and buying rims with the proper hub bore.
 

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Discussion Starter · #16 ·
get a spectrum analyzer app on your phone if possible

strap phone tight to the center console cup holder areas with some blue tape (be like a microphone)

see what frequencies pop up
Gotcha. I was basing the frequency off my sons voice. Lol.

I was planning on changing out the PCV and oil pressure sensor but I guess it could wait another day since those two things will take me a week at minimum to do.
 

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Discussion Starter · #18 ·
shame you cant switch the wheels out one at a time to find the culprit
Quick and dirty would be to find someone with a spare set of Mercedes wheels. That would be an easy way of finding the culprit.
 

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I found the crack because the tire wouldn’t keep air. I did a manual inspection looking for a nail with soapy water with no results. Discount tire found the cracked rim and the vibration started after I installed new rims and kept the original tires. The vibration was pretty apparent after leaving the store. They installed huncentric rings which reduced the vibration on city streets but once I hit the freeway it was clear it didn’t fix everything. It’ll vibrate between 70-80 mph with 75 being the roughest.

I’m thinking it’s either the lugs or leg bolts since I changed out the hubcentric ring last year to make sure they got the proper size.

Before I do any of that I’m going to cross swap my rims to see what if any change that makes.

Everything online says it’s the rings but I don’t buy that since I changed them out. I’m honestly at the point of saying fuck it and buying rims with the proper hub bore.
Honestly, you might be better off buying a whole new set of wheels (even replika ones), and get it fitted properly. If it didn't have this issue before you changed out the cracked rim to the motegi wheel, then it's most likely caused by the installation of the replacement wheel.
 

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Discussion Starter · #20 ·
Honestly, you might be better off buying a whole new set of wheels (even replika ones), and get it fitted properly. If it didn't have this issue before you changed out the cracked rim to the motegi wheel, then it's most likely caused by the installation of the replacement wheel.
I’m getting closer to that being the reality. I just don’t like not being able to solve a problem.
 
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