SL 500 vibration
#11
04-02-2007, 12:06 AM
RE: SL 500 vibration
Mwall,
I understand what you are complaining about. I have experienced the same thing with my Benz, but as anengineer and car enthusiastI could not let it rest. My Benz seemed to have lost that smoothness which made it a Benz. I refused to allow it, and pursued the problem.
Consider the following problems which I found to be the core of how a Benz ends up riding like another make of car.
1) Brake rotors-shopsoften do a crappy job of turning rotors. The equipment has to be clean and in good order to do a precise cut. The operator also has to give a crap about the job. If the rotor is out of perpendicularity to the axis more than .001", the brakes will NOT feel like a Mercedes. The idiot that did my last rotor was out .010!.
2) Tires- I recommend that you jack the car up and spin the tires by hand. Sometimes a brand new set of tires will be deffective and out-of -round. Of course the salesman will never mention that the tires were blem/reject/discount tires from the lowest bidder, but give them a spin and look for any weird out-of -roundness, even measure it if possible. Balancing is also an issue. Few tire people here care enough to clean the wheel before installing the weights; so they fall off quickly. They also need to remove the old weights, glue, and remnants of old weights. If they do not do a careful job of balancing the wheels, it will ride like crap. It has been very difficult here to find anyone at any price that cares about balancing the wheels properly.Usually they just slop it up.
Finally I found a race shop that actually performs work on GT2 cars that understands that I want the car to ride like new, even if it isn't. They understood that the rotors had to be precise, cut AND balanced them, which is only done in racing apparently. They KNOW that tires shake if not round and balanced, so they made them near perfect. This only cost about 25% more than the nimrod dummies. I recommend that you find a good race shop, and tell them that you expect the car to run smooth at 150 mph, and I promise you that they will have the equipment and expertise to make it happen. You simply can't rely on the teenagers at the local tire store to keep your Mercedes in top condition. Sorry if I sound like an ***, but whatever; It only ran like crap after they worked on it.
Today, when I need service, I say this is my car. My car has a name. Her name is Babedy. If anything happens to Babedy, a 300 lb ex NFL linebacker, down on his luck, will show up to kick your ***. Babedy needs new brakes-balanced, tires-premium, and not a single new scratch. I don't mind paying extra; just make sure it happens. If Babedy is happy, I will be happy, Take care of Babedy. They usually figure out that any car with a "name" is special, and the point gets across.
Blue
I understand what you are complaining about. I have experienced the same thing with my Benz, but as anengineer and car enthusiastI could not let it rest. My Benz seemed to have lost that smoothness which made it a Benz. I refused to allow it, and pursued the problem.
Consider the following problems which I found to be the core of how a Benz ends up riding like another make of car.
1) Brake rotors-shopsoften do a crappy job of turning rotors. The equipment has to be clean and in good order to do a precise cut. The operator also has to give a crap about the job. If the rotor is out of perpendicularity to the axis more than .001", the brakes will NOT feel like a Mercedes. The idiot that did my last rotor was out .010!.
2) Tires- I recommend that you jack the car up and spin the tires by hand. Sometimes a brand new set of tires will be deffective and out-of -round. Of course the salesman will never mention that the tires were blem/reject/discount tires from the lowest bidder, but give them a spin and look for any weird out-of -roundness, even measure it if possible. Balancing is also an issue. Few tire people here care enough to clean the wheel before installing the weights; so they fall off quickly. They also need to remove the old weights, glue, and remnants of old weights. If they do not do a careful job of balancing the wheels, it will ride like crap. It has been very difficult here to find anyone at any price that cares about balancing the wheels properly.Usually they just slop it up.
Finally I found a race shop that actually performs work on GT2 cars that understands that I want the car to ride like new, even if it isn't. They understood that the rotors had to be precise, cut AND balanced them, which is only done in racing apparently. They KNOW that tires shake if not round and balanced, so they made them near perfect. This only cost about 25% more than the nimrod dummies. I recommend that you find a good race shop, and tell them that you expect the car to run smooth at 150 mph, and I promise you that they will have the equipment and expertise to make it happen. You simply can't rely on the teenagers at the local tire store to keep your Mercedes in top condition. Sorry if I sound like an ***, but whatever; It only ran like crap after they worked on it.
Today, when I need service, I say this is my car. My car has a name. Her name is Babedy. If anything happens to Babedy, a 300 lb ex NFL linebacker, down on his luck, will show up to kick your ***. Babedy needs new brakes-balanced, tires-premium, and not a single new scratch. I don't mind paying extra; just make sure it happens. If Babedy is happy, I will be happy, Take care of Babedy. They usually figure out that any car with a "name" is special, and the point gets across.
Blue
#12
04-02-2007, 12:14 AM
RE: SL 500 vibration
I just read the last post as well about the harmonic balancer. In my experience, a bad harmonic balancer will shake the car if you rev it up sittin in the driveway while in park. you need to determine if the engine is shaking the car or if the wheels are shaking thecar.
Blue
Blue
#13
04-02-2007, 01:15 AM
RE: SL 500 vibration
Hey Sir:
You may want to check it out first, but you just may need a new harmonic balancer (crankshaft pulley). You can check them out on http://www.worldautoparts.com/pls/parts.asp
Or, Call: 1-800-550-1424
I really hope the best for you in getting ride right....
David
You may want to check it out first, but you just may need a new harmonic balancer (crankshaft pulley). You can check them out on http://www.worldautoparts.com/pls/parts.asp
Or, Call: 1-800-550-1424
I really hope the best for you in getting ride right....
David
#14
04-02-2007, 01:24 AM
RE: SL 500 vibration
Blue,
The key is, "the rhythmic vibration." While sitting idle, the tires aren't doing anything, the wheels arent doing anything, the bearings aren't doing anything. There's nothing moving or turning but the engine. The driveshaft is not doing anything. If he sits idle...no matter how faint...if there's an imbalance, it should be able to be heard, and the sound will be rhythmic. If it's not broken or stiff mounts allowing vibration to translate, what couldit be? The rhythym does not have to be so dramatic as I seen described. However, lack of attention will definitely cause it to become dramatic! So, the proper thing to do would be to have this area looked at as well, while considering other courses to problem solving.
The key is, "the rhythmic vibration." While sitting idle, the tires aren't doing anything, the wheels arent doing anything, the bearings aren't doing anything. There's nothing moving or turning but the engine. The driveshaft is not doing anything. If he sits idle...no matter how faint...if there's an imbalance, it should be able to be heard, and the sound will be rhythmic. If it's not broken or stiff mounts allowing vibration to translate, what couldit be? The rhythym does not have to be so dramatic as I seen described. However, lack of attention will definitely cause it to become dramatic! So, the proper thing to do would be to have this area looked at as well, while considering other courses to problem solving.
#15
04-02-2007, 01:28 AM
RE: SL 500 vibration
Bob,
Thanks for that information! I may not be able to take advantage of this campaign, but at least now I know that there are problems in this area. Thanks again! I'm definitely going to pursue it and see what happens.
Thanks for that information! I may not be able to take advantage of this campaign, but at least now I know that there are problems in this area. Thanks again! I'm definitely going to pursue it and see what happens.
#16
04-02-2007, 05:49 AM
RE: SL 500 vibration
Hi Guys.
I wrote a looooong post this Sunday but didn't send it till I had checked it and it disappeared from my desktop.!! Couldn't face doing it again BUT you have persuaded me to do so.
In one word TYRES but its NOT THAT SIMPLE!!
It all depends on the type of vibration. SHAKE is different to ROUGHNESS and many other terms like ****LE etc. Such terms are used loosely and dependent upon the context and the exp[erience of the person using the term,the meaning can be very different!
SHAKE is when your stomach feels like a jelly being wobbled although you cant really feel any movement in the car.
Some of you are relating to the harmonic damper which may be linked but very unlikely to the shake problem. If this is faulty you will feel the effects with the engine running although the car can be stationary. A faulty harmonic damper gives a period of ROUGHNESS (a bit like brrrr) in an otherwise smooth run up of the engine. Not sure exactly what revs this will occur at since this is different on every engine type. Some have torsional dampers, others don't due to the number and configuration of the cylinders etc.. Easy to spot a failing harmonic damper. Look to see if the crank pulley (this is in fact the damper) is running out of true. The rubber interlayer degrades and on my car started to come away and caused the pulley to run like a "swash" plate. In other cases it is possible that the rubber interlayer may change it nature and therefore its effectiveness as a damper whithout external visible signs.
Simple job to replace. MB won't accept that this is a problem with the damper in countries other than USA. They say it is temp related. Rubbish. If only I could post photos I would share my experience!!!
SHAKE is VERY DIFFERENT. The engine can be stopped but the car needs to be moving at say 20 to 50 mph, usually on a SMOOTH road. The smooth road enables you to spot the problem. If the road is rough you still get shake but your brain considers the shake to be the road surface.
In order to understand (and this is an area where I have career experience) you need to understand that a car is a spring mass system. The car (body) rides on springs. However it much more complex. The springs also have further springs namely the tyres and the suspension bushes. The body is itself also a spring which has many modes. bending, torsion for instance. You the driver sit on a seat which is sprung and your body also acts as a spring mass system especially the females amongst us.
Now as many of you will appreciate a SMALL rythmic input into a spring mass system causes it to RESONATE when the input frequency matches the NATURAL FREQUENCY of the system. i.e. the amplitude of the system suddenly increases from small (can't really observe) to large (very noticeable).
Now known SMALL inputs from the wheels and tyres can excite the engine and body to a point where the small input (low energy Out of Balance forces) causes resonance and suddenly the body directly, or alternatively indirectly, begins to resonate. This whole process is very complex and often involves the engine going into resonance and then the engine (high energy when in resonance) acting as the input to other system etc etc. To further make matters complex RESONANCE doesn't occur only at FUNDAMENTAL frequency but also at harmonic frequencies (multiples of the fundamental).
An aspect a designer's job is to ensure that designs do not allow VERY small inputs to cause a problem. By very small I mean inputs which are likely to be experienced in service. Since the wheel input is caused by OUT OF BALANCE and since it is not possible to have perfect balance THERE NEEDS TO BE SUFFICIENT DAMPING IN THE SYSTEM TO OVERCOME ANY SUCH INEVITABLE INPUTS. However some designs are more successful than others, its all about getting it right so the type of customer you are dealing with doesn't notice the problem IN SERVICE. A good design will tolerate resonable manufacturing, OOB and wear (reduces damping) tolerances.
Convertible drivers tend to be more mechanical saavy than most and also the frequencies involved compared to the natural frequency of a convertible body (less rigid) pose a bigger challenge on convertibles than regular saloons to get it right!!.
Now the next problem. Once you have experieneced SHAKE you become tuned and expert at creating the conditions under which it occurs. Therefore EVEN CORRECTING THE CAUSE WILL BE UNLIKELY TO SATISFY YOU!!
Now here is a little known FACT.
Aftermarket tyres do not necessarily meet OE tolerances especially for something known as Radial Force Variation RFV. RFV is the spring rate of the tyre. This reflects the internal construction of the tyre and since "plys" have to be overlapped etc the spring rate changes as the tyre is rotated. In service this differing spring rate causes the tyre to run out of round WHEN LOADED. This is not the same as out of round UNLOADED which doesn't really matter. With steel wheels manufacturers used to assemble the tyres in a manner to offset any out of roundness of the steel wheel etc. RFV high spot and wheel high spot were offset by matching small dots on the wheel and tyre.
Now we use alloys with cenering spigots this doesn't really help since they are machined and can be considered round. SO THE MANUFACTURERS SPECIFY RFV TOLERANCES DEPENDENT UPON THE SENSITIVITY OF THE VEHICLE TO STRUCTURAL RESONANCES (SHAKE).
Now you have to ask what happens to tyres that don't meet the standard!!
They are not unsafe etc but are MORE likely to give problems in service if a set of conditions come together. Less than perfect wheel, rotor, driveshaft balance etc, a "fussy" customer etc etc.
BOTTOM LINE.
So if your problem has suddenly appeared you have to be certain whether you have just observed a situation which has always existed but which didn't notice or whether the problem has suddenly deteriorated. If the later it can be due to anything in the whole system....including whether you the driver have put on weight etc.
You therefore need to understand carefully any VEHICLE HISTORY at the point the problem started. New tyres? Rotors replaced (use MB and they will be balanced if the car is sensitive to OOB), hit a kerb, shocks wearing. It can be anything and more than likely EVERYTHING to a certain extent, in the system.
Since several of you are complaining I have to conclude that the SL is sensitive to OOB and RFV. However this has to be set against the context that this is an extremely smooth and refined vehicle and therefore in a demanding customers hands there will more than likely periods where shake can be found. Nothing is perfect...and this includes automobiles and seemingly the SL!
Sorry all this doesn't really solve your problem but at least you (hopefully) will now understand a little more about what is happening.
Final thought. Are the wheels and tyres that you are using a MB recommended size and manufacturer? Car manufacturers do extensive testing to weed out problems like these since they are so difficult to put right when a customer flags up a problem. So if you are using something that is not recommended get back to the OE spec...even if you can't control the RFV.
Hope you found this useful.
Stuart
I wrote a looooong post this Sunday but didn't send it till I had checked it and it disappeared from my desktop.!! Couldn't face doing it again BUT you have persuaded me to do so.
In one word TYRES but its NOT THAT SIMPLE!!
It all depends on the type of vibration. SHAKE is different to ROUGHNESS and many other terms like ****LE etc. Such terms are used loosely and dependent upon the context and the exp[erience of the person using the term,the meaning can be very different!
SHAKE is when your stomach feels like a jelly being wobbled although you cant really feel any movement in the car.
Some of you are relating to the harmonic damper which may be linked but very unlikely to the shake problem. If this is faulty you will feel the effects with the engine running although the car can be stationary. A faulty harmonic damper gives a period of ROUGHNESS (a bit like brrrr) in an otherwise smooth run up of the engine. Not sure exactly what revs this will occur at since this is different on every engine type. Some have torsional dampers, others don't due to the number and configuration of the cylinders etc.. Easy to spot a failing harmonic damper. Look to see if the crank pulley (this is in fact the damper) is running out of true. The rubber interlayer degrades and on my car started to come away and caused the pulley to run like a "swash" plate. In other cases it is possible that the rubber interlayer may change it nature and therefore its effectiveness as a damper whithout external visible signs.
Simple job to replace. MB won't accept that this is a problem with the damper in countries other than USA. They say it is temp related. Rubbish. If only I could post photos I would share my experience!!!
SHAKE is VERY DIFFERENT. The engine can be stopped but the car needs to be moving at say 20 to 50 mph, usually on a SMOOTH road. The smooth road enables you to spot the problem. If the road is rough you still get shake but your brain considers the shake to be the road surface.
In order to understand (and this is an area where I have career experience) you need to understand that a car is a spring mass system. The car (body) rides on springs. However it much more complex. The springs also have further springs namely the tyres and the suspension bushes. The body is itself also a spring which has many modes. bending, torsion for instance. You the driver sit on a seat which is sprung and your body also acts as a spring mass system especially the females amongst us.
Now as many of you will appreciate a SMALL rythmic input into a spring mass system causes it to RESONATE when the input frequency matches the NATURAL FREQUENCY of the system. i.e. the amplitude of the system suddenly increases from small (can't really observe) to large (very noticeable).
Now known SMALL inputs from the wheels and tyres can excite the engine and body to a point where the small input (low energy Out of Balance forces) causes resonance and suddenly the body directly, or alternatively indirectly, begins to resonate. This whole process is very complex and often involves the engine going into resonance and then the engine (high energy when in resonance) acting as the input to other system etc etc. To further make matters complex RESONANCE doesn't occur only at FUNDAMENTAL frequency but also at harmonic frequencies (multiples of the fundamental).
An aspect a designer's job is to ensure that designs do not allow VERY small inputs to cause a problem. By very small I mean inputs which are likely to be experienced in service. Since the wheel input is caused by OUT OF BALANCE and since it is not possible to have perfect balance THERE NEEDS TO BE SUFFICIENT DAMPING IN THE SYSTEM TO OVERCOME ANY SUCH INEVITABLE INPUTS. However some designs are more successful than others, its all about getting it right so the type of customer you are dealing with doesn't notice the problem IN SERVICE. A good design will tolerate resonable manufacturing, OOB and wear (reduces damping) tolerances.
Convertible drivers tend to be more mechanical saavy than most and also the frequencies involved compared to the natural frequency of a convertible body (less rigid) pose a bigger challenge on convertibles than regular saloons to get it right!!.
Now the next problem. Once you have experieneced SHAKE you become tuned and expert at creating the conditions under which it occurs. Therefore EVEN CORRECTING THE CAUSE WILL BE UNLIKELY TO SATISFY YOU!!
Now here is a little known FACT.
Aftermarket tyres do not necessarily meet OE tolerances especially for something known as Radial Force Variation RFV. RFV is the spring rate of the tyre. This reflects the internal construction of the tyre and since "plys" have to be overlapped etc the spring rate changes as the tyre is rotated. In service this differing spring rate causes the tyre to run out of round WHEN LOADED. This is not the same as out of round UNLOADED which doesn't really matter. With steel wheels manufacturers used to assemble the tyres in a manner to offset any out of roundness of the steel wheel etc. RFV high spot and wheel high spot were offset by matching small dots on the wheel and tyre.
Now we use alloys with cenering spigots this doesn't really help since they are machined and can be considered round. SO THE MANUFACTURERS SPECIFY RFV TOLERANCES DEPENDENT UPON THE SENSITIVITY OF THE VEHICLE TO STRUCTURAL RESONANCES (SHAKE).
Now you have to ask what happens to tyres that don't meet the standard!!
They are not unsafe etc but are MORE likely to give problems in service if a set of conditions come together. Less than perfect wheel, rotor, driveshaft balance etc, a "fussy" customer etc etc.
BOTTOM LINE.
So if your problem has suddenly appeared you have to be certain whether you have just observed a situation which has always existed but which didn't notice or whether the problem has suddenly deteriorated. If the later it can be due to anything in the whole system....including whether you the driver have put on weight etc.
You therefore need to understand carefully any VEHICLE HISTORY at the point the problem started. New tyres? Rotors replaced (use MB and they will be balanced if the car is sensitive to OOB), hit a kerb, shocks wearing. It can be anything and more than likely EVERYTHING to a certain extent, in the system.
Since several of you are complaining I have to conclude that the SL is sensitive to OOB and RFV. However this has to be set against the context that this is an extremely smooth and refined vehicle and therefore in a demanding customers hands there will more than likely periods where shake can be found. Nothing is perfect...and this includes automobiles and seemingly the SL!
Sorry all this doesn't really solve your problem but at least you (hopefully) will now understand a little more about what is happening.
Final thought. Are the wheels and tyres that you are using a MB recommended size and manufacturer? Car manufacturers do extensive testing to weed out problems like these since they are so difficult to put right when a customer flags up a problem. So if you are using something that is not recommended get back to the OE spec...even if you can't control the RFV.
Hope you found this useful.
Stuart
#17
04-02-2007, 12:00 PM
RE: SL 500 vibration
Stuart,
Thanks so much for taking the time to put together such an informed response. To me, and I'm sure to others, it is quite valuable to understand probable root causes of these kinds of things with our cars.
Let me try to put the generic term 'vibration' into context. If you're old enough to remember a product called Magic Fingers, that you fed quarters into to vibrate a bed, that's the sensation I get through the drivers seat of the car. Not rough, not shake, just constant low level vibration.
I agree wholeheartedly re your comment about 'vibration always being there to some degree and then reaching a noticeable level'; and also about the harmonic balancer's effect.
As for my next steps, tomorrow the carwill be up in the air so I can get to drive train connections from trans-rear with wheels spinning so I can check for any noticeable/visible running errors.I did whack a curb dodging an out of control Escalade and took out 2tires on the right sidewhich got me to change the original Continentals to the Potenzas. At that time, we measured corner to corner, examined struts, shocks, balljoints, etc. with the only 'damage; being strut mounts which were replaced alongwith the tires.
Next stop isback to Tire shop for another round on the Hunter Road Force system and re-doall 4 tires/tyres.
Re the point you made abouttire manufacturers marking the high point with a dot...since my tires are almost new, the dot is still very visible. Does it make any difference to align this dot with some corresponding mark on the wheel (ifthat exists)?
Thanks once again for the wisdom sharing!
Bob
Thanks so much for taking the time to put together such an informed response. To me, and I'm sure to others, it is quite valuable to understand probable root causes of these kinds of things with our cars.
Let me try to put the generic term 'vibration' into context. If you're old enough to remember a product called Magic Fingers, that you fed quarters into to vibrate a bed, that's the sensation I get through the drivers seat of the car. Not rough, not shake, just constant low level vibration.
I agree wholeheartedly re your comment about 'vibration always being there to some degree and then reaching a noticeable level'; and also about the harmonic balancer's effect.
As for my next steps, tomorrow the carwill be up in the air so I can get to drive train connections from trans-rear with wheels spinning so I can check for any noticeable/visible running errors.I did whack a curb dodging an out of control Escalade and took out 2tires on the right sidewhich got me to change the original Continentals to the Potenzas. At that time, we measured corner to corner, examined struts, shocks, balljoints, etc. with the only 'damage; being strut mounts which were replaced alongwith the tires.
Next stop isback to Tire shop for another round on the Hunter Road Force system and re-doall 4 tires/tyres.
Re the point you made abouttire manufacturers marking the high point with a dot...since my tires are almost new, the dot is still very visible. Does it make any difference to align this dot with some corresponding mark on the wheel (ifthat exists)?
Thanks once again for the wisdom sharing!
Bob
#18
04-02-2007, 12:50 PM
RE: SL 500 vibration
Everyone,
Thanks for all the input. I'm checking to see if the harmonic balancer has been replaced on my car but my engine while sitting in park, doesn't vibrate regardless of RPM. Drove my old 1978 Mercury Bobcat station wagon and my full size 1994 Ford Econoline van this weekend and they both drive more smoothly then my Benz. Drove the Benz into work this morning and the thing just shakes/vibratesfairly continously. While I am sure I'm now sensitized, I don't think I am overly sensitive to the issue. My rotors are Benz and due for replacement which I will replace with Benz stuff.
I guess I could go back to the Continentals but given I've had other tires on without vibration,I'm not inclined to think that is my issue. I'll try this local Benz guru next and then I found an article on Benzworld.org, written in German by a Benz engineer.TheGoogle translator wasn't very clean, so Iam having someonehere at work clean it up if they can. Maybe that has some clues.
Mark
Thanks for all the input. I'm checking to see if the harmonic balancer has been replaced on my car but my engine while sitting in park, doesn't vibrate regardless of RPM. Drove my old 1978 Mercury Bobcat station wagon and my full size 1994 Ford Econoline van this weekend and they both drive more smoothly then my Benz. Drove the Benz into work this morning and the thing just shakes/vibratesfairly continously. While I am sure I'm now sensitized, I don't think I am overly sensitive to the issue. My rotors are Benz and due for replacement which I will replace with Benz stuff.
I guess I could go back to the Continentals but given I've had other tires on without vibration,I'm not inclined to think that is my issue. I'll try this local Benz guru next and then I found an article on Benzworld.org, written in German by a Benz engineer.TheGoogle translator wasn't very clean, so Iam having someonehere at work clean it up if they can. Maybe that has some clues.
Mark
#19
04-02-2007, 01:34 PM
RE: SL 500 vibration
I'm in UK so not familiar with Magic Fingers.
Sounds like you refer to a tizz or tingle or maybe the frequency is lower. Sure your transmission shaft doughnuts are OK.
Not good news that you hit the kerb. Sure you didn't bend the driveshaft?
Need to read up on this Hunter balance machine. Not sure how you can balance a loaded tyre since the loading will damp out (at least to a considerabl;e amount, any vibrations. Usually the RFV machine, which loads a tyre determines the spring rate of the tyre as it rotates and determines whether the spec. has been met. Maybe Hunter are using some "Marketing" terminology or maybe I'm just a little out of date.
Since I assume you have alloy wheels, and further assume that they are round (otherwise this maybe your problem) there will be nothing to be gained by selectively assembling them.
Sounds like you refer to a tizz or tingle or maybe the frequency is lower. Sure your transmission shaft doughnuts are OK.
Not good news that you hit the kerb. Sure you didn't bend the driveshaft?
Need to read up on this Hunter balance machine. Not sure how you can balance a loaded tyre since the loading will damp out (at least to a considerabl;e amount, any vibrations. Usually the RFV machine, which loads a tyre determines the spring rate of the tyre as it rotates and determines whether the spec. has been met. Maybe Hunter are using some "Marketing" terminology or maybe I'm just a little out of date.
Since I assume you have alloy wheels, and further assume that they are round (otherwise this maybe your problem) there will be nothing to be gained by selectively assembling them.
#20
04-02-2007, 01:47 PM
RE: SL 500 vibration
Stuart,
Here's the link to the Hunter System. This is the same one the local MB dealer uses as well. Great tool, and does require 'C' level skill to operate. http://www.gsp9700.com/
I'll add drive shaft to the list for tomorrow. I didn't consider it before as when the Potenzas went on the car, it was as smooth as silk for the first 5-6000 miles. Then....you know the rest.
Bob
Here's the link to the Hunter System. This is the same one the local MB dealer uses as well. Great tool, and does require 'C' level skill to operate. http://www.gsp9700.com/
I'll add drive shaft to the list for tomorrow. I didn't consider it before as when the Potenzas went on the car, it was as smooth as silk for the first 5-6000 miles. Then....you know the rest.
Bob