Suspension diagnosis for w123 - PeachParts Mercedes-Benz Forum

JHZR2 · #1 02-03-2011, 09:02 AM

Hi,

This is about the 82 300CD. I have to wonder if my shocks are starting to go bad...

The car rides great. It goes over potholes very comfortably, and is reasonably well planted to the ground, given the tire and suspension setup. Most road imperfections it soaks up. However, once in a while, and I think it is more when the imperfection is raised like a bump, rather than lowered like a pothole, I get the feeling that the car is teetering side to side. It feels almost like a see-saw but left to right on the car.

TIres are properly aired up, suspension is tight, the car shows higher wear on the outer front tread blocks compared to the inners, but this seems to be common for all w123s that Ive owned.

Any ideas? Is this just a shock going bad and so the dampening on either side is mismatched?

Thanks!

vstech · #2 02-03-2011, 09:21 AM

this sounds like classic upper control arm issues to me. I'd look at the rubber UCA mounts, and the swaybar mounts in it, not to mention the upper ball joint that is built into the UCA...

t walgamuth · #3 02-03-2011, 04:35 PM

I'd also look at the rear sway bar links. Funny handling/ride issues can be traced there sometimes.

JHZR2 · #4 02-03-2011, 10:04 PM

Im starting to find that at far left turns, my driver side wheel rubs the guide rod, and it sure looks like the wheel tilts outward as it it is pushing out to the side. Not sure if that is absolutely the case though...

#5 02-03-2011, 10:12 PM

Something is way off, maybe the UCA? I wouldn't drive too far or too fast until you identify the issue.

JHZR2 · #6 02-04-2011, 09:21 AM

So its not just me... the ds wheel tilts out a bit too much a full turn, right?

Because in the bottom pic, it isnt touching the guide rod, but slightly into turning bac is when it will rum, I guess because some suspension angle is coming bac inline.

Everything feels pretty tight and works good otherwise...

vstech · #7 02-04-2011, 09:50 AM

it's not you.
that upper control arm is likely shot and ready to fall apart! get a pic of the control arm! I bet it's as worn as mine was. or worse!

colincoon · #8 02-04-2011, 10:21 AM

That tire is waaayyyy farther out then it should be!! I agree with the UCA's, and it's not a completely expensive part to replace. Do both sides and see if it helps, it really should.

Inspect all the rubber components as well. Not that they would cause this, but if your UCA's are in this shape there's a good chance that the bushings etc. will need attention relatively soon as well.

byronnash · #9 02-04-2011, 10:23 AM

I feel like my car (300TD 84') over turns like that too. But the Upper Control Arms are new as well as the Tie Rods, Steering Damper, and Idler Arm. I'm getting ready to buy parts to work on the lower control arm. It's getting a bit squirrelly at times.

JHZR2 · #10 02-04-2011, 10:24 AM

UCAs?

This is the main thing to see, right?

Both are from the DS, as that is the side in question... I'd obviously replace both...

vstech · #11 02-04-2011, 10:26 AM

that's it, but your pics only show the ball joint and the swaybar bushings. angle the camera to show where it attaches to the body of the car. it's those bushings that matter most.
your ball joint looks great though.

colincoon · #12 02-04-2011, 10:37 AM

Here is a picture of a new UCA. The bushing on the far right of the picture is what might be worn out. As you can see if it disintegrates it can have a LOT of play in it.

Another thing you can try is to jack the front end up and check the wheels for play.

Daman858 · #13 02-04-2011, 11:16 AM

It cannot be fixed. Now send me your chrome bundt wheels ASAP.

JHZR2 · #14 02-04-2011, 11:25 AM

Quote:

Originally Posted by byronnash

I feel like my car (300TD 84') over turns like that too. But the Upper Control Arms are new as well as the Tie Rods, Steering Damper, and Idler Arm. I'm getting ready to buy parts to work on the lower control arm. It's getting a bit squirrelly at times.

My LCA bushing was badly squashed, and was replaced. I don't know if it is really The case, but it may be getting bad again. The thing is, the steering is tight and the car feels good besides the described issue...

Yak · #15 02-04-2011, 11:29 AM

You can see the rub marks on the guide rod in pic 5 post #4.

Are those chrome Bundts? Stock size wheels/tires? No spacers or anything with the wheels? Everything stock?

I'd also look at toe settings and the tie rods.