My right side rear control arm on my '83 123 is starting to rust through on the bottom. It looks like there is good weldable metal around the quarter size rust hole but if the swap isn't horrible I'd rather do the junk yard shuffle.

Can somebody give me an idication on the hassle-o-meter how bad this job is? What's involved in compressing that rear spring to get the arm in?

I had to do this in december. I got one at the junk yard. Support the car on stands. Once you get the bolts out and let it down the spring can be taken out by hand. Rear springs are not under much tension, unlike fronts. One of the bolts is a real B@#ch to get out. I was very reluctant to remove the body mount bolt but when I did the whole rear suspension dropped a few inches and the bolts came out easily then. The body mount bolt looked to be grade 8 and even though it looked rusty it wasn't once I broke it loose. Probably the hardest thing on the project was the emergency brake. The whole bearing assembly is attached to the arm so you will have to slide back the axle. PM me if you have specific questions. Plan on a whole day for good measure.

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1978 450 SEL 6.9 euro restoration at 63% and climbing
1987 300 D
2005 CDI European Delivery
2006 CDI Handed down to daughter
2007 GL CDI. Wifes

The trailing arm is subjected to massive torque stress.
A certified master welder working with an engineer would not be happy trying to weld a rusty one back together.

Liability = DANGER, think of what happens if it fails.

Get a good used one.

Have a great day.

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Listen to Whunter....he knows his stuff better than 99.99% of the people here.

Get a good used on and paint it with POR15 and it won't rust any more.

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Do you need a trailing arm?

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Suggest you send him a PM.
If the rust is where I suspect, he needs a new trailing arm ASAP.

See that's why I would never have a certified master welder and an engineer work on it. Only a novice welder like myself could ever really be satisfied with the job

Thanks for the info Wodnek I may be hitting you up with questions. I found a 123 in the junkyard today. With a rust free control arm. I guess I get to practice on the entire assembly procedure in reverse while I pull it.

R. Leo I'm not familiar with what the trailing arm is. This is a picture of the rusted area. As I understand it this is the control arm.

Attached Thumbnails

 

I'm not trying to nit-pick... just trying to determine if you needed one. Technically, the part is called a 'trailing arm' ...and, yours is the one is on the left side, I believe.

From Fastlane... L2005-16589 Trailing Arm IN STOCK Fastlane Price-> $1568.00

Mine is MUCH cheaper....let me know if you need it.

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Believe you me I appreciate any offers of help, knowledge, or parts! Whether I can use it or not I thought it was called the rear control arm from a line drawing I saw linked when I searched here earlier. (http://************************/BitMapPage.aspx?bitmapid=91&bitmapname=Rear+Suspension)

My problem part is on the right hand side. I've located one in my local U-Pull-it and although I'm sure it would be a ton less hassle to buy it in a box, I need to pull it my self so I can figure out how the damn thing goes in and out.

Yeah, PP; that figures. They sort of make up their own rules/names/prices...



Understood! I frequently use my parts cars as medical cadavers for the same reason.

When doing this project, I suggest that you replace both trailing arms along with installing new trailing arm bushings and subframe bushings.

Here are a few links to threads on changing out trailing arms and related rear suspension work. Good luck, be careful.

Trailing Arm 1

Trailing Arm 2

Trailing Arm 3

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Never a dull moment at Berry Hill Farm.

I know its already been answered but thats junk.....beyond any doubt.....get a good used one.

__________________
Proud owner of ....
1971 280SE W108
1979 300SD W116
1983 300D W123
1975 Ironhead Sportster chopper
1987 GMC 3/4 ton 4X4 Diesel
1989 Honda Civic (Heavily modified)
---------------------
Section 609 MVAC Certified
---------------------
"He who fights with monsters might take care lest he thereby become a monster. And if you gaze for long into an abyss, the abyss gazes also into you." - Friedrich Nietzsche

You're right- a certified Master Welder wouldn't touch that thing.
If any shop's insurance company found out that the shop had done a patch job like that, the shop would be dropped and likely uninsurable after that.

10-4 there good buddy.

It`s not the rust you see that is the problem. It is the rust you don`t see.

that trailing arm is just 2 pieces of stamped sheet metal welded together.
light weight and strong. doesn`t take much rust to weaken it.

Charlie

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That is correct...
What you do not see can kill you..

One more reason I'm glad I live in Texas.

Rust must suck...

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