Upper Control arm nightmare
 

Decided to replace my upper control arms due to worn bushing and a worn ball joint. Passenger side blot was seized to the sleeve - would not budge! So after reading other threads on this problem - I decided I would try to cut the bolt / sleeve with the sawszall. Sawzall cut through the metal great, but it was kind of hard to get the blade in there with the stabilizer bar in the way. At first attempt, I was cutting against the stabilizer without really realizing it!!:eek::eek::eek:. So how bad did I screw this up?? I hate saying this, but would this be an OK situation to fill in with JB weld?

http://img19.imageshack.us/img19/1303/img1746q.jpg

weld it- not the jb kind.

The sway bar tip is rusted too far and needs repair = combine the weld with the repair.


QP1000 Torsion Bar Saver W123, W126 S-Class
http://www.peachparts.com/shopforum/mercedes-parts-reference-library/178104-qp1000-torsion-bar-saver-w123-w126-s-class.html

I'd take whunters opinion.
Next time, maybe use a die grinder.

Agreed.

Unfortunately, You're best bet now is replacement. With a cut like that to the spring-steel that these torsion-bars are made of, I wouldn't trust any type of repair.

Happy Motoring, Mark

There is none with heat treated.

Is there anyone who thinks that if the Sway Bar was going to break it would break at the tips that are at least 1/2 the diameter of the Sway Bar instead of at the scary cut (which I think is more of a Psychological issue)?

I agree with Diesel911. That cut is not significant, and the bar is not heat treated nor is it spring steel-if it were the weld on repair piece would not work. If the end of the bar is usable, I'd put it back together the way it is.

Over the short term. I would agree. The problem over the longer term is that the cut could cause a concentration of stress which could lead to a crack which could eventually cause a failure of the bar.

I believe it is some grade of spring-steel.
I've seen torsion bars snap from rust craters much shallower that that cut. They didn't break immediately, but they did break.
Maybe this stabiliser bar isn't made of such fragile steel, but I'm not the one that will be taking the chance.

Happy Motoring, Mark

My thought was that the tip being thinner would break off first; even with the cut there is still more metal on that section of the bar than at the tip and because it is close to the tip would be subjected to a similar stress.

If that same cut was down there next to the the 90 degree bend I would be worried.

You would think that the welding heat itself and the stress of the metal solidifying after the weld would do something undesirable to the metal; harden or soften it. Niether of which is good for Spring Steel.

Yet the repair seems to work.

I mig welded a bolt to the rusted/broken off end of one of these bars. The car was then driven the 500 miles or so back home and sold a few years later. If the bar were made of a spring steel it likely would have cracked at the weld. On the other hand it's really not a heavily stressed part.

Thanks for all the replies guys. I was actually wanting to sell this car soon (83 240D). And was really bummed out when I did this! I really don't have the time right now to replace the whole thing like probably should be done (I would probably break other stuff yanking it out), and I have no welding experience or anything. I was just wanting to get a feel for how bad of a situation this was so I know how to communicate that to any potential buyers.