Brian McL

I need to replace the ball joints on a 94 E320...you know, the one WITH the integral ball joint in the lower control arm. Expensive 'cause I need to change the whole lower control arm. Is it possible to replace the control arm with an earlier W124 that has the replaceable ball joint? Perhaps a 93 that as the 104 engine.
Interestingly enough I have a friend who has a 95 E320 coupe and it DOES have the older style replaceable ball joints. Maybe these would work on the sedan. Anybody know??? Thanks

bamberger_1

I never heard that the ball joint ever was an integral part of the control arm. It is always been an exchangable part for all the W124 models. After reading your post I checked with my local MB shop and they confirmed this. It is not necessarily a DIY job, since you need a decent sized pressing tool to get them out and back in. But it never calls for the replacement of the whole arm. The part is relatively cheap ($ 30-40) but my guess is about an hour labor each side.

Brian McL

Hi...well, I think they are wrong. The ball joint cannot be replaced in the US spec. W124 sedan for years 94/95. The whole lower control arm needs to be replaced as the ball joint is not serviceable. Now having said that, if your MB shop is able to machine the old ball joint out then install and weld the new one in AFTER making sure they are correctly aligned, then I suppose it is possible to re-use the original control arm, but not advised. I think this is one of those situations to "go with the flow" and not try to re-invent the wheel.

bamberger_1

Hi Brian,
after your reply I consulted my own literature at home, and, I'm sorry to find out I was wrong and you were right, for the cars with an M104 and M119 engine the joint is welt into the arm. Pretty stupid. I could however not find any reason therefore, other than that the MB documents state "the lower arm assembly has been modified, and the ball joint cannot be individually removed" They dont say anything whether or not the whole geometry changed.

Brian McL

Hi...yeah, couldn't find any good reason either. As a matter of fact the coupe for those years HAS the replaceable ball joints. And they have the M104 engine. I have had both lower control arms side by side and I can't see any difference. There may not be any!!!
Brian

AMGDave

I know, resurrecting a 10 year old post... but anyway:

The reason was due to different brakes. The 4-piston front brakes that MB installed on cars with the M104 and M119 engines (specifically, the 294, 295, and 320mm diameter front brakes) have rotors which sit about 6mm closer to the control arm ball joint area. Since the air gap was only about 7mm and the dust shield occupies nearly 1mm of that, MB had to redesign the control arm to create more clearance. This meant changing to a compact ball joint design that unfortnately is not replaceable.

The good news is, usually by the time the ball joint is bad, the rubber bushings are shot also, so you get new bushings at the same time. The bad news is, the only aftermarket late-style LCA is made by Febi... and there have been a rash of reports in the past few months ball joint faliures after only a few thousand miles on the Febis. Check PeachParts and 500Eboard for details. The OE control arms cost twice as much as Febi but also won't fail a few months later.