Serious Clunking from Front-End W126
 

Ive been driving my project to and from work but today when I was just about home I began to experience a major repetitive clunking when applying the brakes. It was severe enough I opted to use the parking brake until reaching my destination. Here are the facts:

• This 1986 300sdl wasn't driven for a few years before being driven daily.
• All brakes needed work. front calipers were rebuilt w/ new pads and the rear has yet to be serviced w/ new pads (arrived today in mail).
• After priming this diesel, I opted to drive it to and from work as I reconditioned the interior to my standards. Since beginning to drive this mothership, the shocks have slowly worn down to what Id label as ****. New parts arrive in mail in a few days.
• The clunking is very severe unlike any broken ball joints I have heard on my truck, etc. Location: Front Right
• No clunking or braking discrepancies in reverse .
• After finally stopping( very hard,sudden stop) via the clunking, when I begin on the accelerator pedal I reach around 2k RPM before a loud clunk, after this "release" I am completely mobile w/o any obvious problems such as shifting, etc.

After some research I have considered replacing the Guide-Rod assembly on both ends but am eager for more educated feedback. Physical inspection didn't show any immediate signs of damage or rotten bushings of immediate repair.

This is urgent because I use this car to get to my parent in which I provide care for, as well as needing the fuel saving goddess for a 5 hr road trip I have to make this weekend.

Best,
S-Klasse Cowboy

PS This is my first Post!

I am expecting great things from this community in a mutual relationship to be

I would first check for a loose bolt on the front brakes. It's happened to the best of us, which is why I always use thread locker now. I've only had a bolt come loose and go pinking away under the car (amazingly I hiked back up the road and found it), but a buddy of mine had the whole caliper come off.

Another thing would be the guide rod mount, which is basically what braces the wheel while the brakes are being applied.

If the guide rod mount was at fault, do you think my issue would be present any any given speed? I did notice some pitting in the rubber at the mount during visual inspection.
I didnt use threadlock on the caliper bolts but I know its necessary. Will check them with tools but they feel very secure.

I would not rule out a worn ball joint. You can confirm by placing a jack or jack stand under the lower control arm with the tire a couple inches off the ground. Place a long pry bar under the tire and lift. If there is play in the lower ball joint, you will feel and hear it.

mount perhaps
 

how about a engine mount ... I had issue several yrs ago with
loosen side bolts on mounts,manifested as clunk in that area
when brakes applied or even in place (high rpm / low rpm).

these are easy to inspect,warm engine,lift the bonnet and dance
the pedal up and down so you can see movement of the whole engine
in my case jump was observed from left to right.

cheers
ChO

Rogviler, you nailed it. I AM missing a caliper bolt but in either cause of effect, the guide rod mount is shot to ****. Repairs being made now.

Peace.

You'll be happier after you do all of the rubber in the front end. It will drive like a Mercedes is intended.

Commencing Front-End rebuild after I replace rear shocks!
Very very excited :D

How about a couple of pictures?

Yes, be sure to get the vacant bolt hole from ALL angles so we can over-analyze it for nine pages. ;)

Glad you got it figured out and that it was something obvious. :2thumbsup

-Rog

This line makes me miss my w116.
Just putting it out there, her name was Citrus Clitoris.
RIP

http://www.***************/secure/PartImages/1234210171.jpg

LOL
Just pullin' your pubes, partner. I will update some photos of my cavalry past and present on the forums sooner than later.

Bilstein HD for shocks.

Well, that's what we do.
 

I kinda enjoy reading those volumes of analysis which are created while discussing a missing grommet or a loose screw.