This morning on my way to work, my car (1984 300D Turbo) began to make a rhythmic clacking sound, which seems to be coming from the area of the left driver’s side rear wheel. It starts out loud and slow as I begin to accelerate and increases with speed. It also seems to quiet down a bit when I take my foot of the accelerator and at higher speeds.
I know my way around the engine fairly well, but I have yet to attempt any kind of wheel or chassis work (if that’s what this is) at all. Any thoughts on what I need to look for, how to proceed, or cautionary tales would be greatly appreciated.
Thanks,
Chris

It sounds like a bad outer constant velocity joint. Have a look at the boot to see if it is still intact. If so add some lubricant to see if it quiets down.

The longer you drive on it now the more damage if it is running dry. If there is adaquate lubrication present in there at this moment then the joint is shot.

I never considered it before but more than the engines in this model can clack.

Do you have hubcaps? If so, check for loose lug nut.

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Charles
1983 300D, bought new, 215k+ miles, donated to Purple Hearts veterans charity but I have parts for sale: http://www.peachparts.com/shopforum/mercedes-benz-cars-sale/296386-fs-1-owner-83-mb-300d-turbo-rebuild-parts.html

Classic CV joint noise.

So I drove home from work that same day without a bit of the sound I experienced in the morning. Now I'm not sure what to think. Just to be safe though, I decided to take another car for the rest of the week until I can get a chance to get the car up on stands to take a closer look. I'll post what I find as soon as I know more. Thanks for all the responses.
- Chris

I have a very similar noise, currently, as well.

To find the source, try and move the main shaft of either axle along the axis of rotation. You may find some play and discover the noise you have been hearing....

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If the boot is intact , where do you add lubricant? and what kind of lubricant to use?

If the joints need grease. You can remove the small retaining clip from the boot on the axle and then insert a syringe between the 2 and squirt in some grease. Normally when they have developed the clack, if the boots are good, its a sign the axle needs replacing.

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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

I had the clacking but it only occurred after an hour on the freeway. If I stopped for a few minutes and then continued it went away. Then came back after an hour.

Replacing the axles cured the problem.