Suspension springs interchangeability - Page 3 - PeachParts Mercedes-Benz Forum

juanesoto · #31 08-19-2009, 02:08 PM

Here are the W123 and W126 model descriptions for further reference.

Now you can figure out which models you should look for at the junkyard...

***IMPORTANT***

Just to clarify, this charts and the conclusions made from them are theoretical results. There are a lot of parameters that might affect the results, including the fact that in most cases the springs to be installed may need to be cut to the proper length. Therefore, I take no responsibility for the results anyone gets attemping to do this mod.

Please remember springs are a very important part for vehicle safety and handling. You should check all the suspension parts, including the springs during any maintenance or modification procedure you attemp to do.

Also remember that cutting springs is a very delicate matter. For no reason at all use a torch to cut a spring. A hacksaw or an angle grinder with the proper cutting disk should be used. Use quenching oil or some other low flamability oil (engine oil) when cutting the springs. Slowly cut a few mm through the spring wire and cool down the piece. Repeat this until the wire has been completely cutted. Remeber to soften the edge of the spring end to avoid injury during installation.

kingdoc1 · #32 08-19-2009, 05:23 PM

Are the correct springs for w123's not available anymore? Is this something I should be removing from all my parts cars before junking?

Forgive me if my conclusion is in error, I am assuming that you would have not expended all the effort on those nice charts if the correct replacement springs were easily available, so no one would have to resort to cutting other springs and making them fit.

juanesoto · #33 08-19-2009, 07:32 PM

Thanks for your reply kingdoc1!

To be honest with you, I don't know if you're right in your conclusion. My guess is that since most of the upgraded springs for the W123 were available only by special request back then, they must be quite rare and unlike to be readily available nowadays. I didn't really researched this.

Actually my main motivation to do this research is that I live in Costa Rica and down here even the original springs are quite expensive, at almost $200 a piece!

Even getting an aftermarket set from H&R or a similar manufacturer would be quite hard on the wallet. The shipping would be a budget killer!

Since there are a couple of importers that buy wrecked Benzes in US and bring them down here to dismantle and sell them as parts, for me its easier/cheaper to use OEM springs from other models...

I thought about using W126 springs in the past, but since I couldn't find any concluding facts, I decided to do it myself. As my grandapa used to say, if you want something to happen, get up from your ass and get it done now!

juanesoto · #34 08-19-2009, 07:40 PM

BTW, I made a couple of calls today and located a 300SD springs set along with a 300TDT front sway bar. The guy wants $140 for the parts. I think I'll buy them and give them a try... Just need to get some additional suspension parts I need to replace while I'm swaping the springs. Wish me luck!!

What do you folks think about my guesstimations?? I really would like some input on this...

Brian Carlton · #35 08-19-2009, 10:29 PM

Quote:

Originally Posted by juanesoto

BTW, I made a couple of calls today and located a 300SD springs set.........

Using springs from the heavier 300SD will likely turn the W-123 into a severe nose high condition.........exactly what you don't want.

Then, when you cut the 300SD springs to bring the nose down, the suspension will get quite stiff.

Find some springs from the lightest gassers made..........280's..........with manual everything..........that will give you what you want.

juanesoto · #36 08-21-2009, 05:34 PM

Hello everyone!!

A couple of days ago I started this http://www.peachparts.com/shopforum/showthread.php?t=258833 regarding to springs interchangeability between W123 and W126 models.

I contacted the local dealer to get a qoute on the parts needed for the ultimate handling in the W123, without turning it into a back killer. The parts still exist, but they will definetely kill anyone on a budget!

Here are the prices:

Front springs (123 321 36 04): $348 a piece
Rear springs (123 324 27 04): $334 a piece
25 mm front swaybar (123 323 69 65): $785 each
15 mm rear swaybar (123 326 46 65): $400 each

The springs mentioned above are the factory ones that if cutted to the same length of the Vogtlands, will have the same travel per load characteristics. The front springs were available in the W123.130 US version with more than 2 pieces of additional equipment (auto tranny is considered standard equipment and therefore are not taken in cosideration). The rear springs were available in the W123.130 general version with upgraded suspension for poor road conditions.

The front swaybar is the one found in some +81 W123 T-wagons. The rear swaybar is found in some special application W123 such as police versions, etc.

Bottomline, better keep the springs you find at the junkyard now that they are available, because eventually they might become scarce as time goes by and buying them from the factory is not an option... at least for me...

Just an FYI

Good luck and happy driving!!

DocSarvis · #37 08-21-2009, 07:57 PM

OEM for many things and many cars are very expensive or not available. In this case after market would serve and be much cheaper. Eibach (sp) makes spings for many coilover applications and I would imagine could get you any sping rate you would need or want in any length. not sure on custom coil diameter? Thanks

a2t · #38 08-21-2009, 08:02 PM

yeh i found same thing for my 124. I ended up buying a aftermarket spring when 1 of mine broke in half, since dealer was pretty expensive. Sadly, the spring is totally different length, now the r/f corner is 1" too low. There must be aftermarket options out there that do work.

juanesoto · #39 08-22-2009, 10:34 AM

DocSarvis and a2t, you're both right.The best option to get the springs are the junkyards.

I'm leaving now to the junkyard to look for the sway bars and the springs... Wish me luck!!

winmutt · #40 08-23-2009, 12:52 AM

The 15mm rear sway is NLA.

I covet my precious.

You can have one made of course. I would love to have a 16 or 17mm rear sway. Urethane bushing might help the stocker. I had a thread about using a 126, but its is 2cm to wide. They might be another chassis that is the right size. W124 maybe?

juanesoto · #41 08-24-2009, 12:33 PM

I went to the junkyard on saturday and I was lucky to find the 26 mm front sway bar. However the place I go to has most of the cars already dismantled. This means they have a huge box with W123 springs and another huge box with W126 springs. The only way of finding the right springs is measuring them with a caliper and a measuring tape.

I explained the manager what I was looking for and showed him the springs list I made. He was quite interested in putting tags with the right part numbers on the springs for future reference. He said he'll tag them all and call me back. If they find the springs I need, he'll give them to me free. He was very happy of being able to properly identify the parts he has for sale!

BTW, as Winmutt said, 15 mm rear sway bars are NLA and hard to find at the junkyard. Seems that finding it or an equivalent is going to be a major quest...

I'll be reporting back once I get the springs.

juanesoto · #42 09-03-2009, 11:16 AM

Update!

I installed rear W126 springs in my W123. These came from an early 300SD. The springs were a bit longer and the the coil wire a bit thicker than the original springs.

However I was using 3 nub pads with the W123 springs. Since the W126 springs are a bit longer, I installed them with 1 nub. As you can see in the pictures, with the right pads, both the W123 and the W126 spring will be the same length. The part numbers are the following:

Rear W126 springs: 116 324 08 04
Rear W123 springs: 123 324 35 04 (this might be different for US versions)

After some driving to settle the springs, the car is now sitting about 20 mm higher in the rear and the front seems to be about 5 or 7 mm lower. The rear is quite nice now. The front still needs to get lower.

About the ride quality, the car feels quite good. The rear is firmer, but without being harsh. Actually the shock absorbers have better control with this springs. I guess since the car was sitting low, the damping capabilities of the shock absorbers were compromised due to the limited travel. Body roll has also been decreased a little bit, mainly because the car now a bit more leveled.

I would definetely recommend this "upgrade" to anyone. You'll get a better ride in the rear without compromising comfort. Also, If you decide you want a stiffer rear end along with a lower ride, you can cut a part of the spring to increase the rate. Also, you can still get the stiffer ride without lowering the car from the coil cutting by using thicker pads.

I'll try to tackle the front springs this weekend. I'll be reporting back.

The pictures from left to right are:

1. Car before swap
2, 3, 4. Side by side comparison of the springs (W123 on the left, W126 on the right)
5. Car after swap

No pics of the front yet...

69shovlhed · #43 05-20-2010, 11:37 AM

member johnhef hooked me up w/ springs from an SLC, pn 115 324 22 04. they are on the chart just 2 places down from the 126 springs juanesoto used. i am gonna put them on my 123 td w/ sls removed and see if they work. i'll post again after installation w/ results. this could be another option for those looking for better rear springs. thanks, juan, thanks john. this forum has been a great help to me in my quest to get this funky old wagon going. thanks all.