W123 300TD non-turbo wagon/estate with manual 5, 220k miles.
Suffering from harsh vibration when putting strain on the driveline in low revs.

For example, accelerating normally in 2:nd, 3:d, 4:th gear from lower revs. Once it picks up speed and engine revs higher, vibrations go away. Also, when only pressing the accelerator very (very very!) lightly so the car barely accelerates, this is not happening. Same goes with engine braking, when the speed and revs get down to a certain point it starts vibrating badly.

Vibrations and associated noise is consistent with engine revs, so this is probably not anything past the transmission. Feels very harsh, as metal against metal.

Where to begin?
Front engine mounts? Rear one? Throw out bearing? Pilot bearing?

Could try to catch a video if it would be of help.

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Tomas, Sweden
1966 Mercedes Benz 230S with OM617.912, automatic. Disk brakes from W108
1983 Mercedes Benz 300TD grey, OM617.912 and 5-speed manual
1983 Mercedes Benz 300TD blue 7-seater, OM617.912 and 5-speed manual

Do you get this vibration when your foot is totally off of the clutch pedal - or is it happening when you are slipping the clutch?

I would check engine mounts and the damper on the propshaft right next to the gearbox.

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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!

motor mounts would be my first choice. It will sound like a guy has a jack hammer going at your frame.

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

I agree with motor mounts. I just replaced them in my 124 and it made a huge difference in my ability to keep my fillings in my teeth.

Chime in on motor mounts as well. Mine are doing what you describe right now.

When they are really shot, and I mean really gone, the buzzing through the whole vehicle structure is really something. Test drove a car once that way.

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Mac
2002 e320 4matic estate│1985 300d│1980 300td
Previous: 1979 & 1982 & 1983 300sd │ 1982 240d

“Let's take a drive into the middle of nowhere with a packet of Marlboro lights and talk about our lives.” ― Joseph Heller, Catch-22

+1 motor mounts and the center mount beneath the transmission too.

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The OM 642/722.9 powered family
Still going strong
2014 ML350 Bluetec (wife's DD)
2013 E350 Bluetec (my DD)

both my kids cars went to junkyard in 2023
2008 ML320 CDI (Older son’s DD) fatal transmission failure, water soaked/fried rear SAM, numerous other issues, just too far gone to save (165k miles)
2008 E320 Bluetec (Younger son's DD) injector failed open and diluted oil with diesel, spun main bearings (240k miles)

1998 E300DT sold to TimFreeh
1987 300TD sold to vstech

Check your front Flex Disk, you do not want that coming apart.

Check the center Support bearing. wiggle the shaft un and down . The rubber part might be gone letting the DL to vibrate.

I was under a car in PNP yesterday. this bearing was totally gone (Rubber part). lots of un and down movement.

The transmission mount was ripped off also on this car, never seen one this bad, so check that out. they get oil soaked and soft.

Check the engine mounts, I have seen them so far gone the engine mount arm is banging on the body.


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

I replaced the front engine mounts, this took away about half of the vibrations. There are still some, will check the transmission mount and the drive shaft discs/support. Currently the car is awaiting Swedish registration so it's not legal to drive anyway..

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Tomas, Sweden
1966 Mercedes Benz 230S with OM617.912, automatic. Disk brakes from W108
1983 Mercedes Benz 300TD grey, OM617.912 and 5-speed manual
1983 Mercedes Benz 300TD blue 7-seater, OM617.912 and 5-speed manual