Strange front shock sticking - PeachParts Mercedes-Benz Forum

eatont9999 · #1 05-29-2012, 07:04 PM

Hey fellas,

My car has been doing this ever since I bought it but a more recent incident confirmed there is something not right. Often times when I have to stop quicker than normal (not even slamming the brakes on) the front end will clunk and stick. When I accelerate the front end will make a pop sound and rise to the normal height. Yesterday I was coming down a hill to a stop sign and turning right. I got the usual thunk but when I accelerated, it didn't pop back up until a while later. The front driver's side felt like it was riding on only the spring (very bouncy). After the car shifted into O/D I heard a thunk from that side and the suspension returned to normal.

I know I need to install a guide rod mount kit on that side because I can rattle the guide rod with my bare hands. The passenger side guide rod is tight and doesn't move. The shocks on the car are aftermarket from Midas or something and they seem to be leaking or have already leaked. My question to y'all is: Would my issue be a sticking shock or would a guide rod cause the suspension to act like that?

Thanks.

Stretch · #2 05-30-2012, 03:18 AM

I'm guessing this is on your '83 SD then?

If your front suspension sometimes goes into chicano mode and does not return to the normal ride height I would stop driving it until you can work out why. That sounds really dangerous to me.

eatont9999 · #3 05-30-2012, 10:48 AM

Quote:

Originally Posted by Army

I'm guessing this is on your '83 SD then?

If your front suspension sometimes goes into chicano mode and does not return to the normal ride height I would stop driving it until you can work out why. That sounds really dangerous to me.

Chicano mode -- I love it. That is funny!

It got stuck that one time. Usually it just pops, clunks and thunks. I'm thinking it is the shock because it is not an OEM spec unit and it looks to have been leaking or already leaked out out. I guess I'll have to throw in a set of Bilstien touring shocks when I get the $$ together to do the guide rod mount.

Stretch · #4 05-30-2012, 01:32 PM

I don't think a sticking shock is going to be strong enough to do that - I could be wrong but I suspect something a bit more serious than that. I hope not. But whilst you are down there looking at the shock check the rest of the suspension very carefully.

eatont9999 · #5 05-30-2012, 01:54 PM

Maybe I should take some pictures and post them because I am not a suspension genius. I replaced all the tie rods and steering dampener and that solved my wobbling problem over 40MPH on rough terrain but that is all I have done. The clunking issue has always been there, I just haven't had the time or funds to address it. I'll take pictures of everything I can down there and post them up.

Last time I checked for play in the front wheels was before I replaced the tie rods and I had 3-9 play and very little to no 12-6 play.

Oh, yeah, the car did sit for a few years and was rarely driven in that time.

Stretch · #6 05-30-2012, 02:20 PM

If you are at all unsure you'll find that you'll get a good response to pictures here - we all love pictures!

eatont9999 · #7 05-30-2012, 11:05 PM

Here are the pictures I took earlier tonight.

Index of /images/83mercedes-benz300sd/suspension

Stretch · #8 05-31-2012, 03:12 AM

I hope you don't mind me adding direct links to some of the pictures you took - it looks like you're using your own server or something like that?

If that isn't OK let me know and I'll edit out the links.

On the whole it doesn't look totally terrible to me - I can't see anything hanging off or snapped off!

However there's evidence of worn out bushings and possibly split ball joint boots? I do think the shock is toast too unless the oil muck is coming from somewhere else. Please bear in mind that whilst they say the camera never lies it is sometimes difficult to diagnose things this way.

Anyway here are the pictures of the bits that concern me.

Can anyone who actually owns a W126 let us know?

Stretch · #9 05-31-2012, 03:17 AM

1) Have you checked to see how loose the bolt is on the end of the anti-roll bar?

It looks loose in this picture - the rubber bushing doesn't look like it is compressed

2) What made the mark in the muck on the shock?

3) How often do you check your tyre pressures?

It looks like you're running under-inflated...

You might also say that the camber is a bit out the inside of the tyre is wearing a bit more than the outside

eatont9999 · #10 05-31-2012, 10:41 AM

You can re-post the pictures all you want; they are hosted on my personal web server. I didn't post them directly in because some forums get upset if large pictures are linked into a thread.

I'll answer your questions in order.

The ball joint boots on both sides of the car are broken. Given the involved process of replacing them, I will have to wait. I might even need to take it to a shop to have them done.

I have not checked the roll bar bolts but I will when I get home.

I made the mark on the shock for perspective. It is caked in dirt and grease. I had an oil drain tube leak and the PS pump seeped a little from the front shaft but not badly when I bought the car.

I noticed the tire wear as well. The guy put air in them before I brought the car home but probably not enough. I'll fill them to 30PSI; I think that's what they take.

I had an alignment done about 6 weeks ago after I installed the new tie rods but once I replace a few more things, I'll take it back and have them check it again. I might as well use that 6 month alignment warranty.

Stretch · #11 05-31-2012, 02:23 PM

The thing with busted ball joint boots is that they usually go hand in hand with worn (as in broken) ball joints. In my mind I can imagine a sticking stubborn ball joint causing the chicano effect more than a shock...

...but this is pure guess work.

More investigative work is needed I feel.

pmckechnie · #12 05-31-2012, 07:03 PM

In IMG-1147 it looks like the shock is bent. Bent shocks can cause the problems you discribe. Anyone else see this?

Paul

eatont9999 · #13 05-31-2012, 08:27 PM

Quote:

Originally Posted by pmckechnie

In IMG-1147 it looks like the shock is bent. Bent shocks can cause the problems you discribe. Anyone else see this?

Paul

I definitely see what you are referring to. I kinda figured it was something to do with the shocks. I guess a set of Bilstein Tourings are in my future.

Do I need a spring compressor or can I jack up on the control arm/have a fat chick sit on the fender? I guess I should do a search, huh? Let's see, "fat chick on fender."

eatont9999 · #14 05-31-2012, 09:06 PM

Oh, I also inflated the tires to 50PSI. The max PSI listed on the tires is 51PSI.

Stretch · #15 06-01-2012, 02:33 AM

Quote:

Originally Posted by eatont9999

Oh, I also inflated the tires to 50PSI. The max PSI listed on the tires is 51PSI.

That's the maximum pressure of the tyre not the pressure it is meant to be inflated to - you'll be bouncing around the road like you are on a po-go stick...