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Suspension Troubleshooting

This component is part of Suspension.


Define the component. Include, if known, the german language word for the component, as well as the English or American equivalent. Show a picture, a diagram.

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Describe, in general terms the function of this component. Meaning what is it there for and what role it plays. Describe how it works, the inside mechanism. Use diagrams to explain.


Describe common maintenance procedures, and common faults that may occur. Describe how these may be diagnosed and resolved. Again, include diagrams, photographs and explanations. Where possible, include measures, tolerances, weights etc.

  • Symptoms when it faults
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Old Yahoo content

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While on a nice sunday drive today I happened to suddenly get a frequency vibration that was entirely new to me. As we were about 50 miles from home, I was immediately worried that something major had happened. Then, at the bottom of the hill it stopped and I couldn't make it happen again. While sitting at dinner with my wife I kept running this event through the back of my mind, a little worried because we still needed to drive home. Finally, I'm a little slow, it occured to me that it happened going down a steep hill but not up the same hill. A slight turn to the left or right exacerbated the problem and only arriving at the bottom of the hill seemed to stop it entirely. I'm home now, with no more weird noises, and I think the problem might be 33 year old sagging springs. Going down that hill with all the weight of the car shifted forward must have loaded those springs enough to cause the front tires to rub on the wheel wells. Especially during turns. I have never worked on this type of suspension. Any suggestions? Would it not be better to have it done by a good mechanic? Am I completely wrong? Could it be something entirely different?

A long shot worth checking is your power steering fluid level. If the level is low or air is present, the car will vibrate and make a loud noise.

Will Samples says: check your driveshaft center support.

I had the opportunity to ride in another 230sl this past weekend and I was very suprised at the difference in ride. mine is all original (needs allot of work) and the other has been restored I found that the other had a much stiffer ride than mine. I don't know if he had any thing changed on the suspension but I am sure that mine is original. I have a 66 230 and I think the other was a 64 was the spring rate different on the first 230s or what. I know that the 280 was supposed to be a lot softer. The difference was like night and day.

Joe Alexander says: sometimes the rear wheel bearing will go bad and seize. Then the entire seized bearing and race spin in the bearing race. It usually is intermittent and does make a noise. The bad bearing will be on the side that makes noise under load. In your case I suspect the right side wheel bearing. The bearing can be replaced without removing the differential. However the bearing raceway may be worn oversize so the new bearing is loose in the raceway. Clean the race very well and use Locktite Stud and Bearing Mount to seat the new bearing. You can also put some centerpunches on the worn race to tighten things up as last resort.

These cars are beautiful, but still ladies past their prime and clearly have dveloped some issues with joints and the like. Actually, I have had 2 280SLs and their behaviour is similiar when going over bumpy roads and rough surfaces. Its not nice to hear the shake and rattle as you feel you're hurting the beauty and I wonder if anyone has experience of changing springs and shock absorbers which might have eliminated these shakes, and the car would drive smoothly and quietly, NEARLY like a new Mercedes. But this might be asking for the impossible?

Hans Strom: the action to take in order to improve the feel of the M-B is to change all rubber parts in the chassis, front and rear wheel mounts and engine mounts. Possibly change the shock absorbers as well, as you mention. The springs themselves are usually OK. My cars run w/o any rattle when passing over bumps.

I think the answer is yes. Since getting my W113 last year, I have replaced the front subframe mounts and all of the rear axle and torque arm rubber bushings. The new bushings and mounts made the car considerably quieter over bumps and rough roads. The most recent change was to replace previously installed KYB shock absorbers with Koni shocks. I understand Bilsteins were standard, but I've always wanted to try Konis and I think they're great. The Konis are both quieter and better riding than the KYBs, but of course I don't know how they compare to Bilsteins. The suspension isn't completely quiet, but it's much better than before.

I have a 280 SL. Since I don't know how it should handle, I don't know if it's ok, or needs some work. When driving in a straight line the car seems to wander and it feels like the front end is "floating" - it takes an inch or so of steering wheel movement to correct.

Hans Strom says: what is described below is the notorious rear-end float, a result of dried-out and aged rubber parts. Typical of all MB W 108 to W 113-type cars of the sixties. In order to counter this float, some rubber parts need to be replaced. These are at each end of the trailing rear axle support arms, which are fitted to all W108 to W113 M-B's. Replace these parts, get your auto a proper four-wheel alignment, and enjoy the stable ride! The rubber parts I refer to are 110-352-10-65 and 110-352-18-65. The side support rubber is important too (parts no 111-351-04-44 and more). Further, there are a number of rubber supports in the front of the chassis which also mean increased comfort and good handling when replaced.

Will: certainly the rear axle rubber is a good idea to refresh. But have you completely eliminated all problems with the front axle? These cars are so well made that by the time they start to handle "funny" there can be a great deal wrong. My neighbor bought a 230 SL two years ago and drove it around and enjoyed the car just fine. He finally wanted to eliminate a front end squeak so we thought we would grease the front end. Jacked up the car, removed the right front wheel and found the upper outer control arm bolt just barely hanging on. It was just a matter of time before the right front axle assembly collapsed. But the handling was just fine.

I drove my ‘67 230 SL for over a year with this slight wandering, thinking I just hadn't got used to the car. I removed, disassembled and resealed the steering box several months earlier, due to a constant puddle under the car. I stopped the leak, but it still wandered. When I took it to my alignment man, he informed me that the right front spindle was worn and that the short wheelbase cars require a tight front end. He explained that the right picks up more road dirt and that the left front was just fine. I was able to obtain all new parts, including upper and lower arm kits that connect to the spindle as well as new kingpins and bushings. This was a full days job as it took several hours of reaming and honing the new bushings in the spindle to accept the new kingpin. This system is unusual in that the upper kingpin to upper (A-frame) arm is a large thread, used to adjust the camber. This is a job best left to a dealer or shop familiar to this system. I'm happy to say that after re-alignment, the car handles like a dream.

Frank says: the Factory specifies a certain amount of clearance in the kingpin bushes, which as I recall can produce about 1 mm of play at the tire. This clearance is necessary to allow the passage of grease, and I don't think it is necessary or desirable to reduce this clearance in order to improve handling. When there seems to be excessive play in the front wheels, I always pump grease into the center fitting and re-try it. If the play persists, it is due to looseness in the wheel bearings, steering knuckle bushes, or elsewhere.

Will: I prefer to use the Febi brand of king pins. Their bronze bushings come with grease channels precut inside the bushing. All I have to do is ream the bushing to fit the kingpin. The only clearance I allow is for the kingpin to fit and be able to be turned by hand without undue effort. Max clearance between kingpin and bushing is .016", the 1 mm is measured at the wheel rim with the brakes applied. If the wheel wobbles more than 1mm, then there is too much play in the kingpins (assuming there are no other obvious problem areas).

Frank, my right front wheel could be lifted about 1/2 inch. I reamed and then honed the bushings until I got a free fit, as I had done years ago when I was a mechanic. I did not have a clearance dimension available, but ended up with about.001-.002 in. I believe these bushings are slotted for grease. My Mercedes manual does show a required end play for the assembled king-pin of about .020 inch. I ended up with about .015. I'd like to correct my statement about the top connection. The hollow threaded bushing is for minor caster adjustments. There is an eccentric bolt that slips inside of this for adjusting camber.

Hans Strom: the (rubber) parts in the chassis can be replaced by and by, there are lots of little things in the chassis. A good tip though is right away changing the steering damper, not so expensive and easy. The reason that changing the rear rubber has such an effect on the steering sensitivity and response is a geometry thing - the worn rubber allows the rear axle to move slightly sideways and it also canters. This in effect steers the car. There is a problem with leaving your car at a workshop. The mechanics in workshops today weren't born when these cars came off the line. Very different from todays "change entire unit" and plastic snap-in technology. Oh yes, be sure to grease the chassis regularly. The grease point (nipple) on the drive shaft itself is the most neglected, I would guess...

Will: another problem you have to be aware of is a shop that will put the 113 on a lift. They typically use the frame as lifting points and allow the front subframe to dangle in mid-air. This puts a huge load on the subframe mounts and causes them to rip apart. This leads to the front of the car sagging and looking like the coil springs have collapsed.

Frank: I always jack up under the center of the sub-frame, then place jack stands under the suspension; this avoids tensile strain on the sub-frame mounts.

On G-forces: I finally found it in a reprint of an old road test by Road and Track in June '69. It can be found in the Mercedes 230-250-280SL Gold Portfolio by Brooklands. They compare the E-Type, The Porsche 911T, Corvette Stingray, and 280SL. The 280SL is dead last at 0.674g 31.8mph) behind the E-Type with 0.718g (32.8mph), the Corvette with 0.764g (33.8mph), and the 911T with 0.782g (34.2mph). It confirms my "seat of the pants" analysis. The SL is no true sports car (nor was it intended to be). For example there is a substantial amount of brake dive and body roll...

Hans Strom: well, don´t completely rule out W 113 performance. Facts are, the 230 SL entered and was competitive in a few rallies in the sixties. Also won the tough "Spa-Sofia-Liege" long-distance road rally in ‘63. When the W 113 was first shown in Geneva, it was compared to a Ferarri 250GT Berlinetta V12 on the little Montreux circuit. The 230 SL had, within 0,2 seconds, the same lap times as the Ferrarri. Uhlenhaut was behind the wheel at that occasion.

I can attest the handling prowess of the 230 SL (‘64 Euro). As I drove at about 50 mph on a two-lane road a Ford darted from a side dirt street in an attempt to cross in front of my car. It appeared no more than 10 feet in front of me and there appeared to be absolutely no way to avoid it. No way to even touch the brakes. I jerked the steering to the right, then back to the left. I missed him by no more than inches, and I passed in front of the car. I was in shock at avoiding the collision. I still don't know how I or the car did it. But it responded to the sharp steering input, maintained its composure as it hit the edge of the dirt cross street, then let me turn it back onto the road. All stock except 205X55X16 tires on Ronal wheels, and gas shock absorbers.

Does anyone know the specs on rear alignment in regards to left/right alignment? My right rear tire will rub the inner fender wells on hard left turns... we're talking REALLY hard turns, but using my best measurements, I can get 1-1/2 fingers between the left rear tire and the inside front of the body, but only 3/4 finger on the right rear side. I know there is an adjustment rod that goes to the horizonal mount that SHOULD adjust the differential Left/Right, but is it really as easy as that? Do I need to loosen anything else? Or just start wrenching? Does anyone have measurements as to what the correct spacing should be? Or should I just make them even?

My car will do the same as I have not realigned the rear axle carrier. The right rear wheel is a lot closer to the wheel arch than the left one. I think there is an axle locator adjustment you can make. I haven't done the adjustment yet but will do so soon. I had to do this on a W 108 SEL when I changed over to a 'Sperrdifferential' Limited slip and had to realign the wheels to make them equal on both sides. And this was done via the locator adjustment, which is on the right side in front of the central pivot(crown pinion box).

Specs are : 36mm , +/- 2mm off-set to right of chassis, measured from the center of pivot pin to C/L of chassis.

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