[AthlonSL500]

Hi all I hope some one has something to add that may help.

Car started vibrating at around 60 mph.. i could see the passenger seat shaking and the steering wheel and pedals transmitted it also very subtle at the outset..It was noted that the ABC line had been pulled and come loose losing fluid. This was very small and had no impact. It went to garage.. this is 3 months on going, and now very expensive. They found both engine mountings shot and the engine was a inch or 2 too low which pulled on the pipes caused the leak. Vibration however, was still there. Got much worse driving a 200 miles trip and began thumping and banging, appeared to be the gearbox now. Gearbox mounting was found to be damaged - They replaced it. Now the car still has a vibration and droning sensation ( like high frequency oscillations) most noticed at 60mph+

So... prop shaft was suspected. Replaced prop shaft bearing and rubber and also both flex plates... car remains the same. Arms were also replaced on the front and basically all joints have been checked .. most have already been recently replaced in past 10k. On occasion the steering shakes around an inch when it is severe.. but mostly it has a slight vibration. They suspected a wheel or tyre next. I had after market wheels on it in perfect condition. Had them removed and checked by a proper wheel engineering shop that straighten them. Found to be perfect. All 4 tyres replaced as they thought it maybe the tyres...still the same... Finally had original wheels refurb with new Pzero's.. is better but still there. Wheel guy thinks it is better a little on the standard wheels because of a diff offset. The issues is being amplified with the offset. The garage called Friday after another week and said basically they don't know what to do with it.. never seen anything like it. But understand that's its bad enough you would not want to drive any distance in it. When its on at 60mph.. going into neutral has no effect.. lower gear higher engine revs same speed, no effect. We think its there all the time just noticeable more at higher speeds. Can ABC failures cause this vibration in the car.. I get no errors or warnings..ever... Owned the car, last 70k miles and pretty much rebuilt the front end including shock ball joints. It feels like a missing engine when its doing it but the engine does not miss.. but that's the feeling through the car. strange pulsing vibration at high frequency I would call it.

Anyone offer any advice. :frown



Can anyone shed any light on what could be the issues.. I am hoping someone has had this experience before.

 

[rudeney]

Have you had a road-force balance done?

 

[AthlonSL500]

No TBH i have owned mercs for many years and never found any issues with wheel balancing. Ive owned this 7 yrs now and had several tyres fitted over that time. Also, it really does not present like a balance issue on a wheel. some days its quite violent.. 1-2in shaking in steering wheel.. other days its mild... slight steering vibration. regardless of speeds. it feels like an unbalanced prop shaft but how, and can that actually happen? it does not change with temperature either.

Hmmm after reading about what it is exactly, never even heard of it - you may be right.. defo worth a try...now to find 1 in Yorkshire Uk.. no easy by first looks.

 

[rudeney]

What happens is that you can have a tire out of balance that is mounted to a rim that is also out of balance. If the two "heavy" (or light) spots are not aligned, the typical balance machine will instruct the operator to place two sets of weights. This won't work. The tire needs to be dismounted (or at least de-beaded) and rotates so that these two "balances" line up and one weight can be used.

Another thing to look at is a wheel alignment. I had some high-speed vibration on my CLK that was a bad toe alignment.

 

[OKB]

first suspect is wheels, tires , alignment. have you done the front camber bolts, had alignment. Try different set of wheels and tires.

 

[edmundo528]

Roadforce Balance is the way to go. I had a Lexus SC430 that had the same issue and We tried every fix. Someone suggested the roadforce balance. And my issue went away after it was done.

 

[AthlonSL500]

Well balance has not worked, made no difference. Please note I have had changed all 4 tyres for brand new on the aftermarket wheels, and also new Pzeros on the original wheels, currently on now...so didnt really expect anything. Garage is stumped, said never seen anything like this, me neither. Slight oscillation in the steering wheel that can become extreme.. seems no pattern to it other than it is worst at precisely 62mph... that has remained a constant. Its not the wheels. All bushing appear ok and as said pretty much been rebuilt over the past 2 yrs anyway. No idea what to do next. This is my first real issue in 5 yrs but tbh.. it will be the last. It has cost a fortune to try and guess what is wrong... and it seems guessing is the only route. Everything that has any play has been replaced using genuine Merc parts.. The suspension system is like some kind of top secret design. i have read some really good posts but again there are some errors in it with regards hydraulics and how they work...so I am even unsure about that guidance. I cant help thinking something is happening in the hydraulics at around 60 mph and transferring into the steering rack etc... Raising the car up has no effect at this speed to the shake. Mechanic said it reminds him of an exhaust bolted to the chassis instead of having a rubber mount.. that,s the sensation you get. This is going to be very unusual for sure so any wild ideas, i'm all ears. Its been aligned and all cambers etc were within spec. No strange noises, no codes, just drives like a bag of &&&& so frustrated.... At 62 mph select neutral or lower gears is the same.. its not related to engine revs. Could also be the prop shaft but again .. how do you bend a prop shaft on these.. sounds unlikely. I'm about to throw the towel and part ex it for peanuts.

 

[OKB]

should be able to see vibration in driveline when car is raised on rack and raise to same rpm as when driving.
then no tire touching ground

 

[AthlonSL500]

Yes they have tried this.. they can not get the car to spin up to 62 mph as the traction control takes over, even when turned off lol... unreal... The fact that the steering wheel vibrates makes me think it originates from the front end somehow.. Im feeling its something to do with the pressures on this ABC.. is it possible the pulsation damper has blown and causing it through the car and rack? Can teh pulsation damper cause issues at all like this.. all i have read says it makes a noise but dont effect the car. Suspension itself appears ok.. been flushed not long ago.

 

[Heatwave]

Just one man's guess based on his experience with a failed pulsation dampener: you would hear a failed pulsation dampener rather than feel it ... sounds a lot like dying belt tensioner bearings. And you'd hear it all all engine speeds.

Suppose you're cruising along at about 60 mph ... the speed at which the vibration begins ... and you cycle the ABC system to raise, then lower, your car, is there any change in the speed or intensity of the vibration? I'm guessing there is no change, but that's just a guess.

One more try: have you ruled out the power steering pump? That isn't mentioned in your posts, but that's about the only thing left that could resonate through the steering wheel.

Good luck, Mate. I hope you get this whipped.

 

[imon_2nd]

Tough problem.

The only thing like that I've ever experienced was on an American car. The prop shaft center bearing was worn out and vibrated at speeds above 60 MPH. When it vibrated, the whole car buzzed; the steering wheel as well. Took forever to diagnose it.

 

[AthlonSL500]

Yeah, I was hoping this was my case... when they removed them they were just fine.. had them changed anyways as it was all out and I had the parts bought..There are no strange noises that would indicate a pulley bearing but I could get them checked out just in case. From what I have read the suspension does something at around 60 mph..lowers, controlled by computer. This is why I am now at the ABC system for the ultimate cause... .. no funny noises though :-( I was hoping someone here was going say.. it is this.. I have heard of this before lol.. seems only the common stuff is reported. Maybe its unique .. not sure if I will get to the end.. spent close on £4k now with parts and labour, 2 sets of tyres and so on...much further and I may as well of bought a new car ..so frustrated.

 

[AthlonSL500]

So mechanics can get to the cause, collecting tomorrow .. on my own lol... I was thinking that maybe it could be the tie rod inner joints. Anyone had these fail? It would make sense why steering shakes i guess. Shes done 120k miles. Keep you updated on what happens next. I intend to fit a new purge accumulator first.

 

[dbischoff]

If you can feel it in the steering and it occurs at specific speed independent of engine RPM, and you have eliminated the driveshaft, wheels and tires as possible culprits, think it narrows the problem down to something in the front end - shock/strut, control arm bushing, tie rod, idler arm, steering damper, ball joint, wheel hub bearing, alignment, perhaps even a brake rotor imbalance.

Or could it be related to airflow? Could something like the belly pan or the front air dam be loose or cracked and resonates when 62mph wind flows over it, enough to feel it?

 

[rudeney]

Generally, vibration in the steering wheel is front end, vibration in the seat is rear. I've had many cars with a vibration at a specific high speed. In every case, it's been either wheel balancing (fixed only by a special road force balancing - not just standard weight balancing) or alignment (toe).

 

[AthlonSL500]

Im back and its worse..still ongoing but progress...been driving a while same speeds but much more pronounced..there is a thump through the car seat feels like the back wheels are not round sometimes..actually felt like the prop shaft.. proper strange. Steering is minimal.. I know the inner track rods are worn a little and have new parts to fit.. but I doubt that has anything to do with the this weird vibration through the whole car. The passenger seat shakes to the visible eye like it's pulsing. Anyway..its been parked up in the bodyshop for touch ups and arches. While sat there i decided to swap the prop and look at the work that's been done myself....the gearbox mount is split and is less than 300 miles old..Question is..split due to excessive vibration or split causing it still...omg...THEN.. its leaving a pool of what appears to be gearbox oil on the floor.. quite a lot, I would say a 1/2 cup a day easily. I have no errors yet or limp mode and the cars been sitting a week.. quite a pool each day.. but I am now thinking the vibration could be a result of low oil and the torque converter oscillating? is that possible even.. looking at it tomorrow. I think it is the 13 pin connector seal. Could this issue be the tranny level all along.. I hope so... PLEASE someone say yes.. that have experienced this... I cant drive the car as yet in bits so i can not really accurately measure how much oil is it.. but i guess its been expelling it for some time..

 

[rudeney]

If the oil were so low as to cause vibrations strong enough to destroy the mount, it would probably not even operate at all. I'd say the leak is the typical pilot bushing seal failure and totally unrelated to the vibrations. What brand mount did you use? Maybe you just got a bad one. And of course there's a lot of cheap crap, even knock-off fake parts out there. I've pretty much stopped buying name brand auto parts from eBay and Amazon.

 

[rorypff]

I would suspect a problem with the prop shaft.

My honest opinion - find yourself a reputable Mercedes Indy, your current one is just costing you money.

Low transmission fluid would not cause major vibrations, and to rip a transmission mount tells you it is a prop shaft problem. You might even have worn out differential mounts.

Good luck

 

[AthlonSL500]

I hear what you are saying indy dealer.. i been to 2.. both said they cant help because the car has been modified... suspension is lowered etc.. exhaust and so on.. THEY say STAR will just exit any tests as the car is outside parameters.. I need a proper mechanic I guess not an idiot with a machine that a monkey can use.. Well when I drive it I hope the prop was the cause and the issue is gone. I dont know if they replaced the part with genuine merc.. I will find out next week. I had no option but to use a motor factor as i was in strip down and needed it then. If it is the mount, then it shud work for 1 or 2 miles lol.. we'll see.

 

[plinker17722]

Athlon i am of the old school . Years ago propshafts or drive shafts in the usa as you call them .I talk bout the shaft that runs to the rear wheels down the centre of the car . We had a quick balancing act for them .These shafts are balanced and must be replaced in the same place as they are removed from .And if this was not done, it will take some sorting out .The way we used to find out if it was the propshaft running out of balance- was to open up two hose clips, open them both out ,.Now screw one end in to the other ,slip it over the spropshaft and clamp them on to the p/shaft by screwing them together to clam them on . Mark it so you know it was the place you fitted it to start with .Now take the car for a spin.This is trial and error .,keep moving the hose clamp around the shaft till vibration is eleviated . Just an idea that cost nothing . If it solves it the prop will need balacing .