My 300D has developed a slight clunk at the left front. I just took it to the shop and we could not find anything except a little vertical movement in the steering box output shaft. The steering box is just about the only part that hasn't been replaced recently, so I'm going to try tossing in a rebuilt steering box and see if that resolves it.

This clunk only happens if I hit the right bump at the right speed and it's still pretty subtle. It's very annoying when it does happen, hopefully the steering box will take care of it.

Anyone have any other ideas?

Have you checked out the front end components? I had a clunk when my tie rod was beat. Then I had a similar clunk when the guide rod mount was beat, but that one also clunked while braking or accelerating.

Right now, my SDL is clunking due to beat upper ball joints. I'm fixing that tomorrow.

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Chad
2006 Nissan Pathfinder LE
1998 Acura 3.0 CL
OBK#44
"Pleasure in the job puts perfection in the work." - Aristotle (384-322 B.C.)

SOLD
1985 300TD - Red Dragon
1986 300SDL - Coda
1991 - 300TE
1995 - E320
1985 300CD - Gladys

Yup, I had all the components replaced about a year ago and we spent about an hour going over everything again this morning. I actually got a bad guide rod mount the first time and had it replaced under warrantee, that was a little different clunk; I could actually feel it in my left foot.

What's going on now is the strearing box shaft seems to have a slight amount of vertical free play, if I push straight up on the pittman arm it will make an audible clunk but it's hard to tell if that's what I'm hearing.

Did you replace the track rod mounts at that time? They can be the most elusive source of a clunk.

Can you feel the clunk at your left foot?

Exact same issue here. I'll be pulling the wheels off on Sunday to review.

Last night I grabbed the front left wheel and gave it good shake and I heard the clunk again. Mostly when I brake or accelerate though.

-Andrew

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'85 300TD "Puff The Magic Wagon" - Rolling Resto
'19 Mazda CX-9 Signature - Wife's sled
'21 Morgan 3-Wheeler P101 Edition
'95 E300d - SOLD
'84 300TD "Brown Betty" - Miss this one
'81 240D "China Baby" - Farm grocery getter

I have an occasional clunk under my left foot in the 240D.....Larry please tell me what you are thinking!

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Current Mercedes
1979 maple yellow 240D 4-speed

Gone and fondly remembered:
1980 orient red 240D 4-speed

Gone and NOT fondly remembered:
1982 Chna Blue 300TD

Other car in the stable:
2013 VW Jetta Sportwagen TDI / 6-speed MT

Yes, that was a different clunk; more of a feeling in the left foot when the wheel tries to move forward or back. That was resolved with the track rod and mount replacement.

This one sounds higher and or more forward (like a tie rood or something) but we couldn't get anything else to make a sound with a pry bar.

Look for a rod that goes from the front suspension back towards the fire wall, at the back end it is connected to the unibody with a bushing in a mounting assemble that's held in place with a few bolts. Try moving that and see if you can reproduce the clunk. When you are driving, you can feel it more than hear it.

If you can reproduce it by hand, it should be easy to find.

Thanks Craig - I am still getting used to your new avatar - have trouble remembering who you are!!!!

__________________

Current Mercedes
1979 maple yellow 240D 4-speed

Gone and fondly remembered:
1980 orient red 240D 4-speed

Gone and NOT fondly remembered:
1982 Chna Blue 300TD

Other car in the stable:
2013 VW Jetta Sportwagen TDI / 6-speed MT

Be nice to peggysue.

Just a thought , if your going to replace the steering box why not try adjusting the backlash on it and then verifying if that in fact is the clunk.

Worst case its tight and you have to manually center it , best case it cures your clunk.

By no means do I suggest driving with it tight but just to check it. My 300sd made a clunking noise that wound up being slack in the box . I was able to dial it out with the adjustment nut.

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Experience : what you receive 3 seconds after you really needed it !!



86 300SDL 387,000? Motor committed suicide
81 300SD 214,000 "new" 132,000 motor
83 300SD 212,000 parts car
83 300SD 147,000

91 F700 5.9 cummins 5spd eaton 298,000
66 AMC rambler American 2dr auto 108,000
95 Chevy 3/4 ton auto 160,000
03 Toyota 4runner 180,000 wifes

I found that the best way to test the rear guide rod mounts was to park the car on a hard/level surface, keep it in Park, release the emergency brake, grab one of the front tires at the 3/9 o'clock position, rock the tire fore to aft and look underneath where the "guide rod" goes into the rear "guide rod mount". If the rod pulls in and out of the mount, it is toast. Having a helper rock the tire while you watch "the rod" is a bonus.

If they are really bad (like mine were) you can grab the rod (with the car on the ground) and move it around by hand. That clunk was really annoying.

Craig... I think you are probably right about the steering box... Did you look at the UCA bolts (through the inner fender well)? Maybe a split upper shock mount? Those subtle clunks are a PITA to track down sometimes....

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AJ

1985 300D (SOLD)

Yup, tried that too, adjusting it helped the free play in steering a little but didn't reduce the vertical free play at all; I think the box is just worn out (500k miles).

Yup, we checked all the bolts and tried to move everything with a pry bar. We even checked the sway bar bushings.