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Discussion Starter #1
I would like to redo the suspension on my 72 280 SEL 4.5L The rear end sags and the front wheels have play. For my MGB there are a number of readily available manuals to explain what parts should be replaced and how to best do so for a suspension renewal. I have been less fortunate finding the proper manuals for my Mercedes. For the rear end sag, does this sound like worn springs? I see no obviously broken parts. If I do replace the springs are there other logical items to replace besides shocks? Are there commonly worn bushings for instance? For the front end, I am sure the bushings are worn, but when buying parts I want to be sure I don’t leave anything out, so does anyone have a good shopping list for a front suspension redo? And if I am replacing springs and shocks in the rear does it make sense to replace the front ones too? Thanks for any help & guidance.
 

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The sag in the back is due to a camber compensator bolted over the pumpkin that has gone bad. The OEM part is a pneumatic cylinder, but there is a coil spring replacement that is a fraction of the cost of the OEM one. I had a W108 twenty years ago, and the dealer had the spring part for cheap. Don't know where you'll find one now, but if you Google "W108," there is an owner's web site that may help.

The front end is worn bushings everywhere. Rebushing the whole assembly will correct the slop there, unless the parts have been metal-to-metal enough to damage them. Again, your W108 web site should provide a shopping list for parts for you.

I had the car you own, and I loved it. I'd love to find another to share the garage with my W220. Good luck.
 

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I've just had the bushes, kingpins, tie rods and bearings replaced on mine and it's made the world of difference.

I chose to do the whole lot as they all pretty much had play in them and it's easier to get it done in one go.
 

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Discussion Starter #4
Thanks for the advice guys! regarding the front bushings - am I looking at upper and lower A-arms? are there others I may be unaware of? I was going to ask about replacing the Kingpins and tie rod ends - so thanks there! I am having one heck of a time trying to find a replacement pneumatic camber compensator cylinder let alone a spring replacement. does anyone know where to find one or if I can repair the one I have? thanks
 

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You'll find the spring replacement here: Mercedes 108 Steering and Suspension Parts, as well as a lot of other suspension parts. To be clear, a worn/faulty compensator will not cause the rear end to sag, it will cause the rear wheels to toe in, perhaps badly. A sagging rear end is likely due to tired springs, just like any other car. The main wear failure in the front is kingpins, give them and the associated control arm bushings a thorough inspection.
 

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I think you refer to bushing collapse and spring pads being flattened. I still don't get the wear part because all they do is twist a little.
 

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you are right Warren,it's highly unlikely the springs have sagged. On top of each rear coil is a rubber pad. There are several sizes available to compensate for expected load and abuse of the car. On the bottom of the spring is another rubber but this is just to stop noise .The lower spring pad is adjustable and has three settings to adjust the angle of the rear wheels. you need approx .5* of negative camber to get a good safe anti oversteer condition.
The two torque arms have rubber bushes in the Diff end and a donut bush in the forward end. These must all be replaced at 100,000 miles. There is a link which centers the diff. The rubber bush's in that will need changing too.
I wouldn't waste money replacing the Boge compensator. Unless you are going to be carrying a bunch of fatties in the back seat,I would just look for a used compensator spring and bracket and bolt that in.
Check the condition of the rear shocks. They will leak oil but that is not a very good indicator of condition,they must be removed and pushed fully down. If they go down easily ,the gas has escaped . If they do not fully compress the oil level has dropped too far. In Either case they need replacing. Replace with genuine parts ($$$) as aftermarket offerings are pretty lousy in general.
don't forget to replace the two front axle mount bush's and the locator rod. Check the condition of the steering column flex joint and replace that if it's worn.
 

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Check the condition of the rear shocks. They will leak oil but that is not a very good indicator of condition,they must be removed and pushed fully down. If they go down easily ,the gas has escaped . If they do not fully compress the oil level has dropped too far. In Either case they need replacing. Replace with genuine parts ($$$) as aftermarket offerings are pretty lousy in general.
Sagging springs are not uncommon on 30+ y/o cars. Also, Bilstein shocks are readily available on the aftermarket. What make Bilstein shocks from the dealer acceptable, but from the aftermarket lousy? :confused: They are identical.
 

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Discussion Starter #12
So if I wanted a reasonable shopping list to freshen the suspension on my 72 280 SEL which cured the rear end sag, and the front end slop it would be:

Front:
King pin kit
Control arm bushings upper and lower
Tie rod assembly (or just tie rod ends?)
Front axle mount bushes
Locator rod
Shocks (as necessary)
Springs to be on the safe side

Rear:
Rubber pads – top of coil spring
Rubber pads – bottom of coil spring
Torque arms rear rubber bush
Torque arms forward rubber doughnut
Rubber bush for link which centers the diff
Compensator spring replacement
Shocks (as necessary)
Springs to be on the safe side

Is this correct?
 

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Add to that the rear diff mount in the center forward section of the trunk.

As far as the kingpins are concerned, there is a proscribed amount of end play. This is corrected by shims. Getting the correct thickness shims takes a dial gauge. See the sl113.org forum for good procedures.

Drive train, fuel, suspension, steering & brakes

and search on kingpin. The 60's SL's use the same suspension, 230, 250, 280 SL.
 

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I also had to have the steering column coupling replaced as it was worn as hell. Might as well check that whilst you are under there and have your hands dirty.
 

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Sagging springs are not uncommon on 30+ y/o cars. Also, Bilstein shocks are readily available on the aftermarket. What make Bilstein shocks from the dealer acceptable, but from the aftermarket lousy? :confused: They are identical.
After measuring a few hundred sets of springs over the years,i have come to the conclusion that it's quicker to merely replace the pads. I have probably seen one set of sgagged mercedes coils on a 1936 220 which was made into a truck and thus overloaded for close on 50 years.
As for shock absorbers,i always by direct from Daimler to ensure i get Bilsteins,not Bilstines,or other variations of brand plagirism.. :)
I have forgotten the number of other brands which i have removed after they failed after a couple of years use.
 

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Add to that the rear diff mount in the center forward section of the trunk.

As far as the kingpins are concerned, there is a proscribed amount of end play. This is corrected by shims. Getting the correct thickness shims takes a dial gauge. See the sl113.org forum for good procedures.

Drive train, fuel, suspension, steering & brakes

and search on kingpin. The 60's SL's use the same suspension, 230, 250, 280 SL.
Warren,while it may seem like a good idea to prevent the spindle from wobbling, the wear will still be in the bushes. Kingpins are getting cheaper and it's no big deal to replace the bushes and get them reamed to the correct clearance. Plus the kits come with new thrusts etc.
 

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After measuring a few hundred sets of springs over the years,i have come to the conclusion that it's quicker to merely replace the pads. I have probably seen one set of sgagged mercedes coils on a 1936 220 which was made into a truck and thus overloaded for close on 50 years.
As for shock absorbers,i always by direct from Daimler to ensure i get Bilsteins,not Bilstines,or other variations of brand plagirism.. :)
I have forgotten the number of other brands which i have removed after they failed after a couple of years use.
You must have had a bad dream. Been in the business for 30 years, and have never heard of, let alone seen a "fake" Bilstein shock absorber. That's just silly. The only other brands I have seen on an old Benz are Boge (aka Sachs) and Monroe (I suspect there may be others), and neither name exactly merits "plagirism".

Oh, and I'll call DB for you and let 'em know they can stop wasting their time and money furnishing replacement springs.

Happy holidays.
 

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German: I put a set of Konis on my W108, so you can add that brand to the list of replacements. That was 25 years ago and the car was still in the "active" replacement parts bins of after-market suppliers and DB even though it was over 10 years old.
 

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you are right Warren,it's highly unlikely the springs have sagged. On top of each rear coil is a rubber pad. There are several sizes available to compensate for expected load and abuse of the car. On the bottom of the spring is another rubber but this is just to stop noise .The lower spring pad is adjustable and has three settings to adjust the angle of the rear wheels. you need approx .5* of negative camber to get a good safe anti oversteer condition.
The two torque arms have rubber bushes in the Diff end and a donut bush in the forward end. These must all be replaced at 100,000 miles. There is a link which centers the diff. The rubber bush's in that will need changing too.
I wouldn't waste money replacing the Boge compensator. Unless you are going to be carrying a bunch of fatties in the back seat,I would just look for a used compensator spring and bracket and bolt that in.
Check the condition of the rear shocks. They will leak oil but that is not a very good indicator of condition,they must be removed and pushed fully down. If they go down easily ,the gas has escaped . If they do not fully compress the oil level has dropped too far. In Either case they need replacing. Replace with genuine parts ($$$) as aftermarket offerings are pretty lousy in general.
don't forget to replace the two front axle mount bush's and the locator rod. Check the condition of the steering column flex joint and replace that if it's worn.
Can anyone explain how to adjust the lower spring pad. I thought the camber was dependent upon the hydro pneumatic strut not the spring pads. My camber is off a little so I thought my strut was going bad. the car sits a little low in the rear too, so I thought I could fix the height issue by adjusting that spring pad, I just don't know if I have to remove the spring or what. The hydropneumatic compensator (strut) is too pricey to replace and it ain't real bad.
 
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