108 question.

[squarebush]

I've been working on my 4.5. . . you know the story anyways it isn't a restoration project, I am really tunning it. Thats not the important part but it needs to be said.
I am cutting the rear springs to lower the suspension. The ground clearance when I began is as follows:
front before wheel - 17in
rocker panel mid section - 10in
rear after wheel - 14 in

vehicle height - 56in

I was planning on cutting 1/2 of a coil and bending the top down. This is the general rule with most cars, however the 108 has ample ground clearance to remove 3-4inchs of suspension. Obviously I would have to compensate for less spring travel to keep from bottoming but I want to greatly reduce the center of gravity.

The question is, what sort of lowering have people done? I have seen some 123 with hydros and airbags but I want to know if anyone else has dropped anything.
I am not going for the low rider look, I just need to keep the back end from sliding about so easily (issue I have had too much). I am 19 years old and I drive recklessly
I would feel bad if I did this to my 108 too.

[Tomguy]

FWIW, with a rear swing axle, and no rear swaybar, cutting the springs would probably make your handling worse and not better. Normally it'd help you corner flatter and produce less roll, but that's counting heavily on a swaybar. Since the 108 has no rear sway, I can imagine the inside tire actually lifting while cornering with a smaller spring.

[squarebush]

well the plan is to put a sway bar in on the rear end. I notice a large cylinder on the dif that looks like a dampener, whats the deal with that?

That is the hydro-pnuematic compensator, it helps keep the rear of the car level and keeps the rear wheel camber at the correct setting.

IMHO, lowering a swing-axle Mercedes will cause a Corvair syndrome, where the rear wheel will want to tuck in during hard corners, and might cause the car to flip. At the least, the camber will be way off, and the rear tires will wear out in short order.

These cars handle pretty well with fresh shocks and good sticky tires, if the alignment is right.

[Blue 72 250]

Originally Posted by squarebush

I am not going for the low rider look, I just need to keep the back end from sliding about so easily (issue I have had too much). I am 19 years old and I drive recklessly

I would put more effort in driving better and not in modifying the design. It is possible to have fun driving and not be "reckless". A smashed up jetta is just another car .... a smashed 108 is sad.

If you are getting the rear to break free that easy then you either have bald tires or a death wish.

[squarebush]

yeah I have some more things to check out. The car needs new tires, an obvious factor, and I am going to check out the front and rear for bushing wear.
I wanted to lower the front a rear of the car, a little for handling and a lightly for aerodynamics. . . good joke, eh? Anyways I was planning on cutting half of the first coil and bringing it down about an inch all around.
Do you all really think that my camber will be that out of wack with only an inch or so gone?

[wbain5280]

Don't cut any of your springs. The car will never handle or ride properly. Cutting springs or lowering cars in all the rage with the Ricers, but not with an MB.

You'd be better off replacing the subframe mounts, rubber bushings and making sure the front suspension is properly greased. That's right, it has a grease point at every front suspension joint, several on the driveshaft and two on the swing axle joint. Get a large grease gun with a flexible line and some good grease, I use Mobil 1 synthetic grease on my 1965 220S. You can use regular grease. If any can't be greased, they must be cleaned. The kingpins must also be done.

The engines are similar but this is for a 3.5.

http://www.detali.ru/cat/oem_mb1.asp?TP=1&F=108058&VIN=

and the front suspension:

http://www.detali.ru/cat/oem_mb2.asp?TP=1&F=108058&M=116%2E980&CT=F&cat=232&SID=33&SGR=001&SGN=01

and the rear axle, see items 318 and 320:
Check item 219, the rubber cuff, for cracks. It may need replacing

http://www.detali.ru/cat/oem_mb2.asp?TP=1&F=108058&M=116%2E980&CT=F&cat=232&SID=33&SGR=001&SGN=01

Driveshaft:

http://www.detali.ru/cat/oem_mb2.asp?TP=1&F=108058&M=116%2E980&CT=F&cat=232&SID=41&SGR=001&SGN=01

and the subframe mount repair:

http://www.peachparts.com/Wikka/W108Subframe

Also, check the engine's chain guides. A broken drivers side chide, one of four, will cause engine damage. Replace all the rubber hoses and plastic vacuum lines.

http://www.detali.ru/cat/oem_mb2.asp?TP=1&F=108058&M=116%2E980&CT=M&cat=042&SID=05&SGR=015&SGN=01

Don't cut any springs to make it ride lower, your tires will wear out fast.

Check the other subsystem links to see how the car goes together. Parts are available.

[squarebush]

what if the differential was raised too? wouldn't that maintain the same dimensions? And isn't that all that matters, maintaining the right angles

[Ara T.]

To keep the back end from sliding out so easily either get A.) New tires or B.) A 240D.

Check your alignment too before doing something stupid such as taking 3-4 inches of suspension out. Try new tires, they'll make a huge difference. With my old tires I could do easily get the rear of my 300D out from a stop, with new tires, you have to be going way faster than you will want to around town to slide the rear tires.

[kalpol]

Don't cut the springs...these cars are engineering marvels - everything is in balance and harmony, and you can't just start chopping on stuff because it will throw everything else out. There's always a reason things are the way they are in a Mercedes, and you can't outthink the engineers.

Get the suspension rebuilt, and you will be surprised at how well it handles. If you're just doing it for looks, well maybe you're better off with another car instead of ricing a beautiful old Benz.

[Tomguy]

Well, logically, you will get a worse ride with a lowered suspension due to the swing axle design than you would if you left it go, square. I know it may sound counter-intuitive. But if you simply cut the rear springs, you will NEED to have a new rear differential mount made. The one in the center. You can't cut and re-weld the original. It's designed for the stock height to hold the axle straight, and if you leave it stock, your axle won't look like -o- (where "o" is the pumpkin), it'll look like `o ́ - which is why I say you'll have worse handling and your inside tire will pick up - instead of your tires being parallel, or slightly curved in, you'll have massive rear camber (along the lines of /-o-\ ). See # 324 on this pic:

[Blue 72 250]

makes me wonder if this kid is for real or if this is one of those "get em all fired up" threads

[squarebush]

no, sorry. What I realized was that I overstated my plans. Anyways after studying the whole problem and I have figured my way around this one. Anyways I figured out that raising the differential and then by bringing the axel up slightly I can reduce the roll angle. The purpose will be to counter act the jacking. Anyways to get the most out of the system I will have to run about 2* of negative camber which will give me the extra cornering force I am hoping for. If I hadn't told you, you would never be able to tell. I lowered the springs about 1" and raised the diff 2". I'll will do some mechanical drawings to illustrate the changes and show the effects on the motion and action.
Though some of your comments were a bit nonproductive, I must say that some of the warnings were helpful and gave me some good places to start my hunt. Anyhow, thanks I won't depart radically from the norms but I would like to tinker a bit. I want to go into automotive engineering and I enjoy working with the 108 because it is well made, well laid out, easy to understand, and robust. There are hundreds of perfect showroom 4.5's, maybe it would be fun to make a drivers car, a lot like the first AMGs. Not this http://cgi.ebay.com.au/MERCEDES-300SEL_W0QQitemZ220103507466QQihZ012QQcategoryZ135586QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

[Arthur Dalton]

Neg camber of 2 degrees is easlily obtained on swing axles by changing the spring pads and turning the spring bottom perches to the lowest position
[ Number 4].
You may also change the hydro to a compensating spring conversion with 3MM pads.
That will do it w/o all the BS.

After all is set , don't forget to centralize the axle to 36mm +/- 2mm to the right of chassis c/l.. that would be to the center of the pivot pin hex head bolt, to the right of chassis c/l...

[Blue 72 250]

now that is what I call BIG PIMPIN' ... love the crushed purple velvit.