I know this isn't a "performance" car, but what could I do to enhance the handling of my 300cd? I'm considering new shocks in the very near future. Do I get factory replacements with 20year old technology or is there something better? I'm putting 16inch wheels from a 99 clk this week. I noticed the sway bars front and rear. Do they come in different sizes? How about urathane bushings? My car is not fast, once it gets going it's great. I love taking it on long curvy drives. I still want a smooth ride, but if I can make it tighter with less sway that would be nice too. Thanks for any help, andy

Koni's or HD Bilstiens will really help handling on this car.

Having auto crossed a 280CE not so long ago, here are some ideas:
set 1 degree or so negative camber in front wheels;
substitute smallest rubber spring seats front and rear;
add rear sway bar from station wagon (1mm thicker)
fill holes in front sway bar bushings on firewall with 1/4" aluminum rod;
substitute shorter slightly stiffer alternate rear springs.
I think I can scrounge up MBZ part numbers if you need them.

Be careful with front wheels and tires. Those tie rod ends are very close. That can be fixed too but you may not want to mess with the spindle assembly.

If you're interested, I've got a set of Performance Friction Z rated pads that will fit your car. Drop a note.

Thanks Autox10, I just put my CLK wheels on and they look great. I had to take the rear ones off. The bolts were too long. I'll buy some shorter ones tomorrow. The rear has all kinds of room left(wheels are 16x7 37mm offset with 205/55 tire). The front wheel comes very close to the tie rod. But it doen't touch. The sway bar from a station wagon sound like a good idea. I'll have to check out the front sway bar to see what you suggested. Do the rubber spring seats come in different thicknesses for my car? I think the car would look much better lowered a bit. What's the best way to do this for my car? Does anyone make "sport" springs for this chassis? Thicker, shorter springs, thicker swaybars, new shocks and new swaybar bushings(polyurethane if possible), I think these things would be perfect if I can find them. Thanks for your help. andy

p.s. do you have part numbers?

I second M.B.Doc's comments on shocks. I used the HDs and was v. happy with them.

Rick Ellinger has a set of springs available, check out:
http://www.rc-imports.com/Parts&Services/racing_parts.html

Front spring seats nub height
123 321 13 84 1 8
123 321 14 84 2 13
123 321 15 84 3 18
123 321 16 84 4 23
Each 5 mm difference changes vehicle height 8mm

Rear spring seats
115 325 22 44 1 9.5
115 325 23 44 2 14
115 325 24 44 3 19
Each 5 mm difference changes vehicle height 7mm

STD front spring 123 313 36 04
Std rear spring 280CE 123 324 06 04
123 324 29 04 lowers car 30mm
Std rear spring 300 CD 123 324 35 04 (I think)
If so 123 324 34 04 would lower car 30mm or so

Std rear sway bar 123 326 45 65 is 13mm
123 326 46 65 is 15mm, that doesn't seem like much but it"s 77% stiffer!
Bushings for 15mm bar are 124 326 21 81.

I've got 2 2 nub front spring seats and 2 1 nub rear spring seats left
over. Let me know if you're interested in them. They cost less than $10 each new.

If you're going to swap springs yourself, use the right spring compressor and be careful. Good luck.

Thank you very much AUTOX10. andy

Autox10(or anyone else that can help), thanks for your help so far. I do have a few more questions. I checked my car and I feel that I would like to bring the front down about 2 to 2 1/2 inches. The springs that Rc imports has will lower the car 2.5 inches. I need to call them to ask how much they cost and how they will affect the ride. Also, can I use stock shocks with the car lowered up to 2.5 inches? One more thing, Is there any way to tell wich springs seats I have on the car right now? I think it would help to know my starting point before I try to go up or down. I'd also like to bring the rear down about 20mm. I think I can get close with the spring seats if I have one of the thicker ones to start with. I appreciate your help. thanks, andy

Spring seat ID
 

Count the number of nubs. They should be visible around the top of the springs. The spacing on my post didn't transfer very well. The 1st 10 digits are the part numbers. The next column is the number of nubs for ID, and then the last column height.

The rears run from 9.5 to 19mm, so the max you can take out is 9.5mm which would reduce ride height about 15 mm.

You may like the back end higher than the front for appearance but if your looking to improve handling you want the back end down as it's the only way to improve camber.

I know this is an old post, but I was wondering if you or anyone else have done these modifications to their coupes? :D

No, Not yet, I am planning on it however.

I do have AMG 17x8 ET28 Aero wheels on my coupe though, actually I have three sets of those wheels. Right now I am on pirelli P7000s, but My pilot sport a/s tires ride much better than even the stock tire size.

I think instead of messing with the swaybar on the top of the car, I am going to make a lower sway bar to fit down there.

Putting on a wagon sway bar is a good improvement.

when I take my engine out I am going to put on 560 SEC brakes on the front, which will be pretty soon.

Lowering Kit
 

I did find a British company that sells a "lowering spring kit" for 123 cars. Lowers the car by 40mm, which is, I guess about 1/2 inch. Made by Ventura for 99.00 pounds. They're at www.europarts.com. Now if I could just find a stiffer front sway bar everything would be all good.

Ray

H & R makes a kit for W123 cars.
40mm/25.4mm/in = 1.57"

Cool!

Where can they be found?

pictures
 

does anyone have pictures of how there projects turned out? i am very curious to know what is being done by all....thanks alot-jake

I put on 560 SEC brakes so far, but thats it, and I got BBS RC307 wheels now. It stops good. I painted my calipers black, but I think red would have looked great, I was trying to avoid looking too ricey.

I am going to redo my suspension in the summer.

W126 springs on a W123
 

Good thread! Very good information!

I recently called RCImports and they don't have springs anymore and don't recommend the brands I mentioned from a British website (www.needforspeed.co.uk). They instead recommended to fit W126 xxxSEL springs (without self leveling) from the junkyard for my 1984 W123 300D.

From my two FSMs, the W126 SEL springs, in general, are longer and have higher spring constants. If I cut them, I can use them on my W123 car, and also increase the spring constant to something I'd find in a real spring kit:D . If all goes well, this will also save a great deal of $, since it is about $170/spring at the MB dealer, and shipping from europe is about the same price of the spring kits!!

Anyone have experience with W126 springs on W123 cars? Any forseeable problems? I'll update as my project progresses.

I put non turbo front wagon springs and the smallest caps they make on my '82 wagon. Previously it drove like a bus on the interstate, now it's tight and handles much better. My 80 TD ran so much better at high speed it was silly so I entertained and then did this swap. Worked great. No HD shocks on wagons... it's a no no with the SLS.

I have two 123 wagons, a '79 (with '85 turbo engine) and an '85 Federal. I've always wondered why the '79 feels tighter and handles better than the '85, and felt that the springs in the '79 are stiffer. Are you saying the non turbo springs are stiffer or have a different spring rate?

I've even thought about finding some alternative springs and replacing the ones in the '85 it just feels too soft.

I'm looking into lowering the nose of my 300D Turbo when I complete the frontend rebuild - currently is nose-high traveling down the road - looks like a boat -

Experimenting with another set of 300D Turbo springs & will try cutting one complete coil out, then maybe two...

Weather hasn't been cooperating this week - :mad:

bnc

How much effect will this have? I will be auto crossing my sedan next month and noticed how much better the W114 handles. Cheap is good for me right now and 1/4 aluminum rod is easy to come by.

Cutting springs so that you end up with better handling is a tricky business. The first thing you ought to do is insure you have the smallest spring cap you can. I do not know if the springs on non turbo models are shorter or stiffer, but they certainly did the trick in my handling/high front end problems. I had a 80 wagon and it was much better handling at ALL speeds than my 82 wagon. I went to the junkyard got some 80 wagon front end springs and small end caps and had my indie swap them out. The car was a completely different animal after, and I really liked the results.

The front sway bar is already thick enough... go bigger and you'll be plowing off the side of the road. Get a thicker rear bar, get some lowering springs (easier said than done), some new shocks, replace old sway bar bushings front and rear, and some speed rated tires with stiff sidewalls and it should handle a lot nicer and shouldnt ride too hard.

Do you know the part number for the non-turbo springs you found? The FSM has all the spring properties, but there are multiple springs listed for most models.

I bought some W126 300SD springs from the junkyard yesterday. Only the fronts, though since the car was resting on the rear rotors and propped up on spare tires in the front. The springs are part number 126 321 16 04. I haven't tried fitting them to my W123 yet, but the outer diameter of the W126 spring is roughly 10mm wider than my current springs.:( Anyone know if the rear springs are interchangeable?

Also, does anyone know the front/rear weight distribution of the 300D-T? I'm working on a spreadsheet to calculate which spring to use and how much to cut off.

Thx

I'm livening this thread up to continue a discussion I started in Diesel forum.

I have 3 sedans, 78 200D, 83 300D euro, 85 300D federal. My 85 federal has so much slop in the rear it sickening. I think one of the sway bar ends is loose as it leans much further in corners to the left than right. At any rate I was comparing the 85 federal to the 83 300D. The 83 has signifigantly different springs than the 78 or 85. They look like this :
http://winmutt.com/images/benz/W123-R-Springs.jpg

Is this a TD spring? I am fairly certain the 83 euro served most of its professional life as a taxi, its the right color, the rear has no seatbelts, the right rear door is worn all to hell.....

Anyways the 83 handled like a dream. I am def swapping rear ends and going on the hunt for a TD sway bar. I have the 1 dot pads as well. For those who have chopped their springs, how far were you able to go before the camber adjustment was of no longer use?

http://www.peachparts.com/shopforum/diesel-discussion/170431-group-purchase-vogtland-springs-w123-need-interested-members.html?highlight=vogtland

I hope that you saw that thread regarding the springs.

Kmac offers a kit for adjusting the camber for the rear of the w123 cars, with using their polyurethane bushings/bolt kit.

Austin

Where are these Kmac units? I sound like an old record but when I talked with reps at SEMA in 2006 they said they could not get them...

Here is my back axle...
Lowered 45mm with ventra springs (out of UK)
All new suspension - including most Long or HD parts
No wagon rear bar - read it is not good for under/over steer...should find out!
17x7.5 Monoblock wheels
Bilstein HD shocks
Cann't rememeber what spring cups we used...

Jake

I wouldn't cut more than one link- at least from the front. Even with all new suspension bushings, my coupe sits right at the edge of whats still within spec after an alingment.

Springs
 

I put a 300D turbo engine in my 240d with a manual tranny and the front end dropped ALOT. It handled awsome though, then I blew the engine. :behead:

Fuel regulator or shut off valve or whatever went while I was haulin ass and the rpms went through the roof, car wouldn't shut off, cars redlining, panic ensues, black smoke is billowing out the back. I think it might blow up or something so I run across the street and watch her DIE.
She started back up and got me all the way home, 30 miles and never ran again. Thats a real car.

I'll have another soon though.