300SDL Advice Needed: Driver's Side Upper Control Arm / Sway Bar Connection Broken - PeachParts Mercedes-Benz Forum

chasw3 · #1 12-01-2012, 09:37 PM

I recently had to slam the brakes on my '87 300SDL to avoid an accident. My wheels locked up and as I was skidding to a stop, I heard a thud (the sound was very similar to the transmission shifting hard as a result of low vacuum). I made it home and realized that the ball joint broke off that connects my sway bar and upper control arm.

I read a post where someone else broke a piece off their rusted sway bar and mentioned it was a $1000 fix with an indy mechanic due to the nature of the repair. I could be wrong in my visual diagnosis, but it doesn't appear that the sway bar itself is broken. If possible, I'd really like to repair this on my own and save the money.

I see that there is a threaded connection. Does anyone know how I can fix this? I've attached a few photos for reference. Thank you for any suggestions or advice!

300SDL Advice Needed: Driver's Side Upper Control Arm / Sway Bar Connection Broken-1.jpg

300SDL Advice Needed: Driver's Side Upper Control Arm / Sway Bar Connection Broken-2.jpg

300SDL Advice Needed: Driver's Side Upper Control Arm / Sway Bar Connection Broken-3.jpg

Mark Rapier · #2 12-01-2012, 09:52 PM

Here is the $100-200 answer to your problem

http://www.peachparts.com/shopforum/mercedes-benz-tools-reference-library/178104-qp1000-torsion-bar-saver-w123-w126-s-class.html

vstech · #3 12-01-2012, 09:59 PM

it looks like the bolt just fell out.
you need a new bolt and washer set, along with new bushings for the swaybar connection.

vstech · #4 12-01-2012, 10:03 PM

nope. I see in your pic, that the end is indeed broken. you will need the repair end to avoid pulling the entire false firewall from the car to change the entire swaybar.

chasw3 · #5 12-01-2012, 10:25 PM

Thank you for your reply. Are you referring to a specific replacement part ('repair end') that I would need to buy to fix this myself, or do you mean that I need to take it somewhere to get the entire swaybar replaced?

I added a few more pics for extra detail. The last image is from the opposite side of the car (passenger's side, still intact and functional).

300SDL Advice Needed: Driver's Side Upper Control Arm / Sway Bar Connection Broken-4.jpg

300SDL Advice Needed: Driver's Side Upper Control Arm / Sway Bar Connection Broken-5.jpg

300SDL Advice Needed: Driver's Side Upper Control Arm / Sway Bar Connection Broken-6.jpg

300SDL Advice Needed: Driver's Side Upper Control Arm / Sway Bar Connection Broken-10.jpg

Brian Carlton · #6 12-01-2012, 11:16 PM

Quote:

Originally Posted by vstech

nope. I see in your pic, that the end is indeed broken. you will need the repair end to avoid pulling the entire false firewall from the car to change the entire swaybar.

It appears that your original diagnosis was correct. The bolt and bushing and washer on the forward side has disengaged and allowed the bar to come loose. The threads appear to be fully intact and not damaged in any way. There appears to be some significant corrosion on the forward face, but this does not appear to be a fracture of the bar.

If the bar is fractured, there is an available kit to weld a new tip to the bar. Replacing the entire bar (10 hours work) isn't cost effective for a vehicle of this age.

vstech · #7 12-02-2012, 01:20 AM

Quote:

Originally Posted by Brian Carlton

It appears that your original diagnosis was correct. The bolt and bushing and washer on the forward side has disengaged and allowed the bar to come loose. The threads appear to be fully intact and not damaged in any way. There appears to be some significant corrosion on the forward face, but this does not appear to be a fracture of the bar.

If the bar is fractured, there is an available kit to weld a new tip to the bar. Replacing the entire bar (10 hours work) isn't cost effective for a vehicle of this age.

nah, look at the pic, there is no where near enough threaded end to clear even the inner part of the UCA... it's broken. the threaded end should stick out of the inner bushing, and have plenty of meat to reach the outer bushing.

OP, click on the link in the 2nd post, and then click on the link in whunter's thread, and look at the part that needs to be welded onto the end of your sway bar. the instructions for what needs to be done are also in that link... the end of your bar needs to be cut smooth, and the new end needs to be welded onto it.

mespe · #8 12-02-2012, 09:33 AM

It would help if you took off the rubber bushing before taking pictures.

Brian Carlton · #9 12-02-2012, 11:08 AM

Quote:

Originally Posted by vstech

nah, look at the pic, there is no where near enough threaded end to clear even the inner part of the UCA... it's broken. the threaded end should stick out of the inner bushing, and have plenty of meat to reach the outer bushing.

Yes, I see it now........surprisingly clean at that break, however. The bar must have been two inches longer.

Brian Carlton · #10 12-02-2012, 11:19 AM

This link explains, in detail, what is necessary.

http://www.peachparts.com/shopforum/mercedes-benz-tools-reference-library/178104-qp1000-torsion-bar-saver-w123-w126-s-class.html

You'll need to bring the vehicle to a certified welder to be able to do a proper job on the heat treated swaybar.

You'll also need to prep the swaybar by cutting it to a reasonably accurate length.

LandYaghtLover · #11 12-02-2012, 02:12 PM

Been there, done this. Both sides even though one side was all that broke.

You will have to cut off the end, nice and square, and weld on the new ends. If you just ran a bolt there is a high probability, no matter the strength, that is will bend or break off. There is just not enough metal.

Replacing the ends is pretty simple. You MUST cut the end to the proper length. You may have a couple millimeters of play, but it really needs to be spot on. With that said, when welding you could make minor adjustments. The sway bar and uppers are not adjustable via alignment.

As for a certified welder... if you really want to. Mine have been holding up fine since I bought the car. The sway bar end these weld onto is not really flexed in any way. That action happens more in the long run between arms at at the bends. The concern is welding tensioned steel. but I have no issues simple having an experienced friend make the welds. Just make sure you clean, prime and paint the ends after welding.

qwerty · #12 12-02-2012, 02:17 PM

Quote:

Originally Posted by LandYaghtLover

The sway bar and uppers are not adjustable via alignment.

If necessary, the outer UCA bushings could be shimmed to a more forward position.

Diesel911 · #13 12-02-2012, 06:41 PM

Unless there is a special kit for your Year and Model to use the W123 Kit the OD of you Sway Bar has to be the same.

One or 2 of our Members had drilled the end out for Studs and used something to Sleeve the Stud to the OD of the Original projection. Instead of a Bolt going thought the Control Arm the Stud goes through and you uses a Self Locking Nut or you can double Nut it.

Sway Bar issues, front and rear.

vstech · #14 12-03-2012, 12:44 AM

the "something" or spacer you can use on the bolt is an alternator spacer from a 617 upper bracket... I'm pretty sure it's the same diameter...

pawoSD · #15 12-03-2012, 12:56 AM

Can always go crazy and do a full bar replacement!

Here is the thread when I first did it on my dad's now retired '83 back in 2005:
http://www.peachparts.com/shopforum/body-repair-restoration/138289-w126-epic-has-begun-project-sway-underway.html?highlight=epic+project+sway
Ironically, the car was retired in January 2010 from a bad trailing arm, so it made it just over 5 years from when the sway-bar project was finished.....then 4 months after the car was retired, I broke the bar on my '82. So I pulled the '83 completely apart, took the nearly-new bar back out, and dismantled mine and put it in the same way, in a WEEKEND back in April 2011.

That was intense.

Its a well traveled sway bar. I may even retire my '82 this spring as its deteriorated to the point that I don't want to deal with it anymore, so when I strip it down the bar will be removed once again. (along with most everything else thats usable)