Evenin all,

I've known for quite some time that my gold SD is going to need a replacement lower control arm as its current one has 3-4 holes in it and I didnt quite feel comfortable with just welding them shut and going on with life.

I've decided to replace it with a good used one. The local junkyard had a 420SEL with good arms on it so I had them pull the one I needed and made it out of there for $50.

Now I'm cleaning/stripping and hoping to do some rebuilt work on it.

Tomorrow I'm going to take it up to my shop and see how much they'd want to replace the bushings and the bearing. The 420 had 150k on it but beyond that I dont know much about it and I figured I'd might as well replace the three things that are on it that I could.

I also have to buy a replacement dust shield/guard as the old one was bent/rusted. Phil has it for $35. From the looks of it this gets assembled when the bearing gets installed.

I have a few questions if anyone is reading:
1) Can the rear bearing be done with the arm off the car?
2) Should I paint the arm before or after I have bushings/bearing replaced?

Here's several pictures for posterity, you never know when someone needs a good picture of a part:


http://i.imgur.com/ATvbsl.jpg
http://i.imgur.com/W5Zrbl.jpg
http://i.imgur.com/sa4Npl.jpg
http://i.imgur.com/UK6VVl.jpg
http://i.imgur.com/ASSCil.jpg
http://i.imgur.com/8eiRZl.jpg
http://i.imgur.com/jFMinl.jpg
http://i.imgur.com/CZcYVl.jpg
http://i.imgur.com/Eskfwl.jpg
http://i.imgur.com/mfaTml.jpg
http://i.imgur.com/ld6Mol.jpg

Wow that looks lovelly!

Are you going to clear coat it to preserve that virginal look?

I've done the rear wheel bearings by myself - with help of a home made wooden vice - and I did it off the car.

As usual with me there's lots of reading (sorry)

http://www.peachparts.com/shopforum/diesel-discussion/277341-w123-rear-wheel-bearing-removal-help-needed.html

Both of my Trailing Arms have a few small rust through holes in them.
However, I hit a 3 inch high island in the Road and cracked the Drivers side Trailing Arm.

I had right and left Trailing sent to me UPS from a Yard in my State. I installed the one to replace the cracked Arm just as it came to me and that was over 3 years ago. I have had zero issues with it.
I did not replace the Bearings in the used Arm I put on the Car. I never changed that other Arm and am still driving around with the tiny holes in it.

I had saved the old cracked Arm and eventually bought the Tool needed to remove the Nut on the Arm.
I Pulled off the Hub using an old Rotor to wack on (instructions in our DIY Section).
(It looks like any method of removing the Hub destroys the Bearings Good or bad.)

With the exception that I had more room to swing the Big Hammer removing the Hub would have been easier if it was attached to the Car.
It should not matter much assembling the new Bearings until you reach the point where you need tighten the Nut and set the Hub Clearance/End Play.
setting the End Play may be easier if the arm is attached to the Car.

You certainly cannot put the Welded Tubular parts of the Arm in a Vice because they will bend/crush if you put a lot of force on them.

Since I already did it; I would use the Arm just as it came from the Junk Yard and see if the Bearings are still good in it.
If you decide to replace the Bearings I would buy them youself so that you get good quality ones (it is too much work to replace them).

If you bought the Tool and an old Brake Rotor you could pull the Hub off yourself and you could see the Bearing numbers and go hunting on Ebay for some USA or Japan Bearings.

She is real sexy now you have her all stripped down. :rolleyes:.

I replaced both Trailing Arms on the 85 300D when I was doing the Sub Frame and trailing arm Bushings. I found them on another 85 a 300CD with just over 200K. got them both for $42 ea.

I just left the bearings in that they came with, figuring they were new compared to my old 350k miles ones. they still are running good. swapping in lower mileage trailing arms was easier than changing the bearings.

Now you have them down to bare metal, degrease them real good with Marine Clean, treat the metal with Metal ready, and throw on a couple coats of POR 15.
I POR`d mine, but being in Calif and no rust issues, I degreased, sanded the arms and sub frame down and painted with POR.

It looks rusty in the splines,but I have seen that before, and maybe in your area with the salt might be more so. I would slap on the anti seize before installing the axles.

Welding on the arms would not be a good idea. with some pin holes showing, there is probably more rust on the inside.
there was a couple threads with pictures showing cracked arms from corrosion. not a pretty picture.

Charlie

That looks too good to have spent its life under a car in Ohio.

Hmm
 

I suggest you remove the rear sway bar link "ball stud" from each trailing arm before further work/cleaning..

Fastlane: Sway Bar Link, Rear torsion bar To trailing arm
http://catalog.peachparts.com/item.wws?sku=W0133-1637060

Fastlane: Sway Bar Link, Rear torsion bar To trailing arm
http://catalog.peachparts.com/item.wws?sku=1233200989

Thanks for all the advice guys, my email had been sending my peachparts notifications to spam so I had no idea.

But my plan with this arm is as follows:

It was from 420SEL that had been in a junkyard up here for about a year maybe or less, it had 150k on it i think. I figured its off the car, might as well rebuild it completely. Its got some scrapes from when they moved the car around, let's strip it down and recoat it. I recently completed a rust removal/restoration on my green SD. The coatings I used on that were pretty robust and cost effective. I ordered a new round of them for this arm and upcoming rust removal/restoration work on the gold SD.

So I sent the arm up to my mech to have the bearing, bushings and protective plate redone.

-I'll get it back tomorrow, coat it, seal it up all nice.
-Drop the existing arm, repair the rust hole and damage.
-Install the "new" arm
-Have the back glass replaced and resealed.
-Then its on to the transmission problem (http://www.peachparts.com/shopforum/diesel-discussion/303941-superior-shift-kit-300sd.html)

I will, of course, post pictures of progress and update this thread with respect to the arm.

Alrighty gents,

I got the arm back from the shop, all nice and rebuilt. They charged me $225 for parts+labor. They were pretty easy on the labor aspect, only charged $70.

My cousin is up from Georgia and she brought her Canon EOS Rebel XTi with her....

PICS OF EVERYTHING!

First I cleaned the metal with the painting prep stuff (Eastwood Pre) to make sure that anything I applied had a good bonding with the metal.

http://i.imgur.com/MuTw7l.jpg
http://i.imgur.com/8JWpnl.jpg
http://i.imgur.com/gAcFpl.jpg
http://i.imgur.com/DWkQ4l.jpg


Then I am applying three coats of rust encapsulator to both sides of the arm:

http://i.imgur.com/nsKDQl.jpg
http://i.imgur.com/T1i06l.jpg
http://i.imgur.com/kUHQLl.jpg
http://i.imgur.com/OgKOwl.jpg

Then, two coats of heavy duty chassis paint (Eastwood Extreme Chassis Black)
[pics later]

Then maybe two coats of rubberized undercoating (not really sure about this one yet, havent decided)

Looks great - a real resto job.

I can't believe you are considering smearing rubber junk all over all that hard work - especially after your first hand experience of MB RUBBER $%$&^%& undercoating...

Army,

You know, you're right. The original arms were not coated with any rubber compounds. I think my current plan of 3 coats rust-encapsulation and 3 coats of the hard chassis paint.

I think that will be a very robust covering. Perhaps comparable or even better than the factory coating. This stuff is pretty robust/tough.

I'm even thinking of dropping the other control arm on the car and repeating the process (minus the complete rebuilt...maybe just bushings)

I've got more pics coming too :) Maybe I'll actually break down and pick up one of these cameras. They're like $400 for the body, lens, and the standard accessories.

More Pictures

http://i.imgur.com/VxnKol.jpg
http://i.imgur.com/bOZnhl.jpg
http://i.imgur.com/YTsHxl.jpg
http://i.imgur.com/ONPCvl.jpg

Hmm
 

Why do you still have the junk ball attached. :confused:

Its only in there to keep paint/coatings from going into the threads and mucking things up.

Its just hand threaded in right now, same reason i have screws in the shock bolt threads as well.

OK
 

Good idea. :)

Alright I am dubbing the arm coated. I have 3 coats of the rust-encapsulator stuff (which is pretty heavy duty stuff) and 4 coats of heavy duty chassis paint. I suspect the car will rust away before this arm does.

I will post up final pictures when my new camera comes in. I caved and picked up a Canon EOS Rebel T3...

In the meantime, I've started the restoration project for my other SD...
http://www.peachparts.com/shopforum/bodywork-repair-paint-tools-tips-tricks/304380-300sd-rust-restoration-project-2-a.html#post2780594