The car is a '81 300SD

Whenever I run over a small bump or rough road I get a rumbling, low pitched rattle from the front right side. At first I thought it might be coming from the back, and checked the sway bar links, but they're good. My guess is either upper control arm or strut rod bushing. I checked both, and the upper control arm looks like it could be original, and I didn't get any play when I pulled on the strut arm. I put Bilstien comforts on the front about 3 months ago. The exhaust system is tight.
One interesting thing happened this evening when I checked the front wheel. When I bounced really hard on the front right fender, a loud click came from the wheel, I then jacked up the wheel, spun it a few times, checked for excessive play in the bearings and put the car back on the ground. Then when i bounced on the fender again, no clicking noise. Any guesses? Thanks

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'81 300SD

Did you check the wheel bearing play on the other side of the car?

Sometimes you think the sound is coming from one side but in reality the other side is at fault. Rumbling - as you describe it - sounds like a wheel bearing problem to me. When did you last repack the bearings with grease?

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1992 W201 190E 1.8 171,000 km - Daily driver
1981 W123 300D ~ 100,000 miles / 160,000 km - project car stripped to the bone
1965 Land Rover Series 2a Station Wagon CIS recovery therapy!
1961 Volvo PV544 Bare metal rat rod-ish thing

I'm here to chat about cars and to help others - I'm not here "to always be right" like an internet warrior



Don't leave that there - I'll take it to bits!

Could be the Guide Rod mount. Look for the rod that comes off the lower control armm to the body. that bearing gets worn and will complain as the suspention move up and down.




Could also be a dry/bad wheel bearing.
Charlie

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there were three HP ratings on the OM616...

1) Not much power
2) Even less power
3) Not nearly enough power!! 240D w/auto

Anyone that thinks a 240D is slow drives too fast.

80 240D Naturally Exasperated, 4-Spd 388k DD 150mph spedo 3:58 Diff

We are advised to NOT judge ALL Muslims by the actions of a few lunatics, but we are encouraged to judge ALL gun owners by the actions of a few lunatics. Funny how that works

So I took off both wheels to check the brakes and linkage. The left brakes were worn twice as much as the right, which makes me think I have blockage in the right line since the wheel doesn't drag much when I spin it. Maybe what I'm hearing while driving over bumps is the pads rattling against the rotor.
The outside boot on the right tie rod is ripped which probably explains the rubbing sound that I sometimes get when turning the wheel at slow speeds or a stop.
There's a knocking sound that I can't locate when I move the right steering knuckle from left to right. It's either coming from the idler arm or the tie rod. Is the idler arm rebuild a tough job? Thanks for your help.

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'81 300SD

Have a look here for a step by step multicolour picture festival:-

W123 Tie/Drag Rods and Idler Arm Rebuild DIY

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1992 W201 190E 1.8 171,000 km - Daily driver
1981 W123 300D ~ 100,000 miles / 160,000 km - project car stripped to the bone
1965 Land Rover Series 2a Station Wagon CIS recovery therapy!
1961 Volvo PV544 Bare metal rat rod-ish thing

I'm here to chat about cars and to help others - I'm not here "to always be right" like an internet warrior



Don't leave that there - I'll take it to bits!

Not hard at all. 1 big bolt, knock the old rubber bush out, put the new in & then put the new bolt in. About as hard as replacing pads.

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Grumpy Old Diesel Owners Club group

I no longer question authority, I annoy authority. More effect, less effort....

1967 230-6 auto parts car. rust bucket.
1980 300D now parts car 800k miles
1984 300D 500k miles
1987 250td 160k miles English import
2001 jeep turbo diesel 130k miles
1998 jeep tdi ~ followed me home. Needs a turbo.
1968 Ford F750 truck. 6-354 diesel conversion.
Other toys ~J.D.,Cat & GM ~ mainly earth moving

Thanks guys,

I'll tackle the tie rod and idler arm sometime in the next two weeks. Even if the rumble still persists afterwards, these will be good R&R's to tighten up the steering.

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'81 300SD