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I can't see how changing these arms will make any difference....
(now on forth suggestion of this and you haven't responded)... I can see the inner ball joint on the steering rack may well be a player in this issue - as it would leave the wheels free to wobble unrestrained
Well drove it today after the torque strut bushings installed, and no change in symptoms. Had to die trying.
Next steps is to replace the upper and lower control arms.
Anyone have any suggestions like just replace the lower arms?
Johnny
My suggestion would be to just do it all. The parts are quite reasonable, and what you have is old and best case scenario is they won't fail for a little while longer.
2007 S600, 2007 Chrysler 300 SRT8, 2000 C5 Corvette, 2017 Mustang GT, 2023 300C, and a 2019 Lincoln
I agree. These cars are very heavy and the weight is supported by those lower control arms and the ball joints loosen over time due to wear and the relatively heavy tires/wheels. The problem is it is very difficult to check those ball joints. With the old American cars cars, you could grab a wheel and shake it, twist it, and otherwise move it to check ball joints wear. With our heavy W221, that wheel might not move unless the suspension is preloaded. My tech showed me how insidious the ball joints and control arms are to diagnose. So I just relented and bought the entire suspension kit from FCP Euro - KIT221-ABC, and if it wears again, they cover the costs of the part on their warranty. The parts were Lemforder which is not Chinesium. After the new parts were fitted, the only issues I had were two bent wheels (surprise- No) which got refurbished at $200 a wheel. Now all is smooth. Runs like new.
I think the whole suspension kit was around $800 after a discount and there were six components: uppers and both lowers. well worth it if you have more than 60K miles on the car. If you don't want to go for the whole kit due to your budget, at least do the lowers since they carry the weight. You will be happy.
I agree. These cars are very heavy and the weight is supported by those lower control arms and the ball joints loosen over time due to wear and the relatively heavy tires/wheels. The problem is it is very difficult to check those ball joints. With the old American cars cars, you could grab a wheel and shake it, twist it, and otherwise move it to check ball joints wear. With our heavy W221, that wheel might not move unless the suspension is preloaded. My tech showed me how insidious the ball joints and control arms are to diagnose. So I just relented and bought the entire suspension kit from FCP Euro - KIT221-ABC, and if it wears again, they cover the costs of the part on their warranty. The parts were Lemforder which is not Chinesium. After the new parts were fitted, the only issues I had were two bent wheels (surprise- No) which got refurbished at $200 a wheel. Now all is smooth. Runs like new.
I think the whole suspension kit was around $800 after a discount and there were six components: uppers and both lowers. well worth it if you have more than 60K miles on the car. If you don't want to go for the whole kit due to your budget, at least do the lowers since they carry the weight. You will be happy.
Thanks for the historical repair for this symptom.
Im going to spend the money on, the front end lower control arm rods, bushings, and ball joints.
The shop is recommending a wheel alignment check/adjustment after work on the lower, so I’ll throw that in as well.
It sounds like these lower control parts are mostly taking the weight and are tired.
I’ll schedule it to be done and get back with the results.
Thanks again for sharing your histories.
Johnny
Last edited by johnnyrocket52; Dec 20, 2024 at 01:09 AM.
I can't see how changing these arms will make any difference....
(now on forth suggestion of this and you haven't responded)... I can see the inner ball joint on the steering rack may well be a player in this issue - as it would leave the wheels free to wobble unrestrained
Hi Botus,
Do you have a drawing of the front suspension to post?
Are the lower arms and bushings part of the steering system?
I think its part 35 that's the cause - made of chocolate and falls to bits around the correct mileage - and so rarely thought about no one looks
ABC def has a different lower arm - bush in 120 falls to bits - the strut fails to connect to part 70 due to a ridiculous design of almost zero connection (just luck)
change to special washers on part 100 to adjust geometry on the camber (right side is wrong on LHD and RHD cars at the factory because the build is a sick joke....) - only fools use the silly weak bolts - as it's made wrong at the factory and needs a one off correction grind the crap off the subframe like the expert dealership's do it - note tracking will be miles out after applying camber fix and must be corrected
202 333 03 76 or 221 333 01 77 Washer for adjustment work only (you need two per bolt)
I think its part 35 that's the cause - made of chocolate and falls to bits around the correct mileage - and so rarely thought about no one looks
ABC def has a different lower arm - bush in 120 falls to bits - the strut fails to connect to part 70 due to a ridiculous design of almost zero connection (just luck)
change to special washers on part 100 to adjust geometry on the camber (right side is wrong on LHD and RHD cars at the factory because the build is a sick joke....) - only fools use the silly weak bolts - as it's made wrong at the factory and needs a one off correction grind the crap off the subframe like the expert dealership's do it - note tracking will be miles out after applying camber fix and must be corrected
202 333 03 76 or 221 333 01 77 Washer for adjustment work only (you need two per bolt)
Thanks Botus, I’ll discuss this modification with the shop next week after scheduling in the lower control arm replacement.
After the Torque Strut Bushing replacements, the vibration seems a little worse.
Thanks Botus, I’ll discuss this modification with the shop next week after scheduling in the lower control arm replacement.
After the Torque Strut Bushing replacements, the vibration seems a little worse.
johnny
In response to your suggestion about the proper operation of the driveline, tomorrow the shop will relocate the driveline on the rear dampener and look at the carrier bearing for no binding from being misaligned or failing, to see if the vibration can be modulated.
The tires have checked and re-checked so many times, even by Doctor Wheel, I think I beat that horse to death 10 times over, not feeling it to be root cause. The only way to fully rule it out is to buy completely new rims and tires, and that ain’t gonna happen. The wife would hide my dead body in the garden.
From many folks experiencing changing out mainly the lower control arms, and the vibration went away, I’m hopeful that’s the fix.
Side note: Working all these years in the semiconductor industry, sometimes the root cause and fix don’t fit “the model”. No ideas are too crazy, well most.
Happy Christmas,
Johnny Rocket III
Last edited by johnnyrocket52; Dec 22, 2024 at 01:32 PM.
Hi Arrie, I remember you posted about the importance of centering the rim to rule out the source of the vibration. My rims I believe are MB.
These are the rims which arrived on the car. I’ve seen other cars on the internet with them as well.
I found again in the forum this vibration turned on for many folks at about 90,000 mile.
I’ll know more Monday as I’m taking it in to have the torque strut bushings replaced.
I’ll update next week week.
JR
I have not seen wheels like this before but they obviously are MB wheels.
But still, they need to mount snug on the center “shoulders” on the hubs. Have you verified this? It really needs to be a snug, almost tight fit between the wheels and hubs.
If you observe the balancing machines they have spindle with cones that wheels mount to. There always is a tight fit between wheel and the spindle on these machines. Make absolutely sure you have this “no clearance” fit for the wheels in your car.
Vibration has frequency that is caused by some moving part and for suspension this moving part is the rotating tire/wheel. Other parts are stationary and CANNOT cause vibration. Loose joints etc. will allow vibration to occur but the source for it is the moving part(s).
Then…I don’t remember…has the propeller shaft center bearing and flex disks been discussed in this threat yet?
I have not seen wheels like this before but they obviously are MB wheels.
But still, they need to mount snug on the center “shoulders” on the hubs. Have you verified this? It really needs to be a snug, almost tight fit between the wheels and hubs.
If you observe the balancing machines they have spindle with cones that wheels mount to. There always is a tight fit between wheel and the spindle on these machines. Make absolutely sure you have this “no clearance” fit for the wheels in your car.
Vibration has frequency that is caused by some moving part and for suspension this moving part is the rotating tire/wheel. Other parts are stationary and CANNOT cause vibration. Loose joints etc. will allow vibration to occur but the source for it is the moving part(s).
Then…I don’t remember…has the propeller shaft center bearing and flex disks been discussed in this threat yet?
I agree with the rotating wheel theory. All of the checks seem to rule it out.
The front flex disk in the output of the transmission was replaced due to cracks. No change in symptoms.
The driveline appears to be a two piece driveshaft. Rubber dampener on the output of transmission and one on the differential. It looks like there is a carrier bearing assembly in the middle of the two piece driveshaft. I’ll see more this morning at the shop up on the lift, guided by the master mechanic.
johnny
Last edited by johnnyrocket52; Dec 23, 2024 at 11:42 AM.
I agree with the rotating wheel theory. All of the checks seem to rule it out.
The front flex disk in the output of the transmission was replaced due to cracks. No change in symptoms.
The driveline appears to be a two piece driveshaft. Rubber dampener on the output of transmission and one on the differential. It looks like there is a carrier bearing assembly in the middle of the two piece driveshaft. I’ll see more this morning at the shop up on the lift, guided by the master mechanic.
johnny
The driveshaft and carrier bearing was inspected and deemed ok. The rear driveshaft was loosed and rotated a few holes on the rear dampener.
One of the front wheels bearing appeared a little loose with free play. The.bearing nut was snugged up to get the free play good.
No change in symptoms.
Ordered the lower A arm assemblies and will get them swapped out soon.
Johny
Last edited by johnnyrocket52; Dec 24, 2024 at 03:39 AM.
The driveshaft and carrier bearing was inspected and deemed ok. The rear driveshaft was loosed and rotated a few holes on the rear dampener.
One of the front wheels bearing appeared a little loose with free play. The.bearing nut was snugged up to get the free play good.
No change in symptoms.
Ordered the lower A arm assemblies and will get them swapped out soon.
Johny
Just got the car back from the shop after the lower control arm assembly #120 and #70 were replaced. They showed me the originals, and they stated in their experience everything on the arms and underneath was in really great shape.
No change in symptoms.
Other folks had good luck with that, but not I.
Next step is to take it to the MB dealer, pay $250, to have them evaluate the underside.
Will report back with the findings.
Johnny
Last edited by johnnyrocket52; Jan 24, 2025 at 12:07 AM.
did you see kevm14's recent post on rear suspension.... some hidden ball joints make the car wander at the back - but a later post in that thread says lots of vibrations come from old exhaust hanger rubber bushes getting stiff
I agree with the rotating wheel theory. All of the checks seem to rule it out.
The front flex disk in the output of the transmission was replaced due to cracks. No change in symptoms.
The driveline appears to be a two piece driveshaft. Rubber dampener on the output of transmission and one on the differential. It looks like there is a carrier bearing assembly in the middle of the two piece driveshaft. I’ll see more this morning at the shop up on the lift, guided by the master mechanic.
johnny
Can you verify that your wheel mounts snug on the shoulder on the hub?
Can you verify that your wheel mounts snug on the shoulder on the hub?
I was back to the tire store and the mounting points on the hubs and rims were wire brushed very well and torqued back onto the hubs up in the air.
The shop zeroed the balance machine, fine balanced, verified runout and road force were low. He said the last shop (Dr Wheel I presume) was off on all wheels by 1-3 ounces.
After visiting Dr Wheel many weeks ago the vibration had gotten worse below 62mph. After the shop’s work last week for free (I buy all of my tires there), the vibration got a lot better below 62mph. I think Dr Wheel didn’t zero his balance machine and is a quack.
I wish I had the money to try completely different rims and tires to cut the problem in half.
I’m told by many the MB stealership will have the same tire balance machine as everyone else. No secret wonder balance machine.
For $250 the stealership will diagnose the suspension and driveshaft and maybe tell me what’s wrong to fix? Muffler hangars, rear suspension grommets?
Thinking that’s a good move as my wallet is injured.
After the lower arms replacement, upgraded torque strut bushing, and the last visit to the tire shop, it’s pretty smooth up to 62mph.
From 65-75 mph, put the car in neutral, and it’s got the same historic rumble going on like a tire is out of balance.
Trying keep it low budget as possible.
Johnny
Last edited by johnnyrocket52; Jan 25, 2025 at 12:31 AM.
90+ percent of vibrations on the freeway are going to be tires/wheels. Seven year old tires? Toss them now before one decides to blow out for a torn up fender liner or worse. Very often a wheel that is not perfectly straight will make a mystery shake. It balances out OK on the machine but it shakes on the road.
Driveshaft vibrations are at Differential ratio times MPH for how fast it shakes. Figure Wheel speed X 2.5 roughly. Feels very different from a tire/wheel shake.
A C/V shake will be only under load. Usually at higher speeds. Lift the loud pedal and shake stops.
Suspension components that are soooo worn as to contribute to vibrations are a clear indicator of an owner who is not looking after his junk.... Also... Suspension parts will make a tire/wheel/brakes shake more dramatic.... not be the root cause of a shake.
Take care of your junk guys!
Balance out ok but constant mystery shake at 65-75 mph, not changing in frequency with speed, winner is, rims/tires.
2007 S600, 2007 Chrysler 300 SRT8, 2000 C5 Corvette, 2017 Mustang GT, 2023 300C, and a 2019 Lincoln
The rims on the S600 are very susceptible to potholes. I had a similar vibration, had my wheels trued, polished, and otherwise straightened on a huge hydraulic machine; and the vibration is gone. Cost me $200 a wheel. You could try one and see. You already have spent a lot.
The rims on the S600 are very susceptible to potholes. I had a similar vibration, had my wheels trued, polished, and otherwise straightened on a huge hydraulic machine; and the vibration is gone. Cost me $200 a wheel. You could try one and see. You already have spent a lot.
I’m starting to believe, somehow, it’s the wheels. Is the best way to know is to measure the rim without the tire with a runout gauge like a LVDT (linear variable differential transformer). We use them at work to measure linear movement down to .001mm
The guy at the tire shop just felt and looked at the rims to define runout and maybe the real issue is being missed with that method.
I’ll shop around for a shop with serious referb equipment and good customer testimonials.
Last edited by johnnyrocket52; Jan 25, 2025 at 01:19 PM.
Balance out ok but constant mystery shake at 65-75 mph, not changing in frequency with speed, winner is, rims/tires.
If the shake frequency does NOT change with speed then it is NOT about the wheels or tires or any other power train part. Any rotating part in the train changes frequency with speed meaning the shake frequency would change too if caused by any part of this train.
It is two problems. I had the same problems. Changed out the entire front end components with new FCP OEM parts. Upper and lower control arms, forward and rear, and tie rods. Technician also said the OEM wheels are easy to bend (duh!). He suggested wheel repair; I bought remanufactured for the right rear. That took care of it. Wheels were hard to find.
It is definitely those lower control arms. They are also particularly difficult to check for wear. You need to put a load on the suspension when you grab that wheel and shake hard. I replaced mine at 92K miles.
I replaced the lower control arms and no change in symptoms.
The wheels balance out in spec. Do you recall what method was used to determine an out of tolerance wheel to cause this mystery vibration?
A rotor can also be out of balance for a shake this, ..infrequent but it can happen
Remove rotor and place on balancer run at speed the shake occurs at....It used to be those could be balanced too nowadays just replace the rotor
I bought all new tires and replace the front rotors/pads with MB originals. Bled them. Worked like new as old ones were warped.
No change in symptoms led me to go after lower control arms.
I have left front wheel with 21 lbs downforce. The other 3 are below 1, 8, 7.
Maybe get that 21 lbs downforce below 10 like others? That will involve moving tire around rim to get it below 10? The Discount Tire Rack is telling me <25 is OK.
Been reading here and there <10 lbs downforce is desirable to rule out wheel vibration at speed in sensitive high end cruisers.
JR
Last edited by johnnyrocket52; Jan 28, 2025 at 01:43 AM.
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