I was driving my 300D today and it started making a loud somewhat of a low pitched whine from somewhere in the driveline. It doesn't occur all the time but usually at higher speeds and I guess more often when I was slowing down a little. I thought that it was coming from the transmission for a while but when I coasted it in neutral it continued. Could this be coming from one of the CV joints or could it be the center driveshaft bearing. I couldn't tell exactly where it was coming from because it reasonated throughout the interior. It's got me worried.
Anyone have any similar experience?

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DJ


84 300D Turbodiesel 190K with 4 speed manual sold in 03/2012

Center bearing can whine, grind, roar, or vibrate. Clue is that the sound is constant so long as the car is moving and is located roughly at the rear edge of the front seats. Vibration can be felt most stronly on the tunnel right next to the front seatback.

Differential noises almost always "trolley" -- sound like the electric motors on an electric trolley, with the frequency changing with speed. Excess or offset clearance will cause a diff to whine, usually only in float, coast, or acceleration, almost never more than one.

Suddenly appearing noises are usually the center bearing or carrier going bad, diffs and rear CV joints are usually gradual in onset.

Rear CV joints almost always show up as vibration.

A bad tranny mount will show up as excessive roughness on shifts and a thumping vibration on acceleration.

A bad center u-joint will sound like a bad muffler and shake the floorpan.

I'm sure I missed something obvious (like the short in the GC at work that had it down for a week).

Peter

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1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!

I too am experiencing a very similar sound in my 87 300DT and have been thinking of asking the same question.

My center shaft bearing is new, so I know that is not my origon for the sound, but when PSFRED mentioned "excess or offset clearance" with the differential, are you refering to the bearing adjustment of the input shaft in the diff. ring bearing?

If so, maybe mine is worn! When I put it into reverse, or into forward, there is a bang, but not real hard! There is an amount of play in the drive shaft that I don't think should be there and I now think the whine I hear, usually around 55mph, could be the differential?

I'm interested to follow this post and find out what develops.....

I didn't notice any vibration in the driveline. The sound is more like a hum and the strange thing it tends to go away sometimes but then it comes back when I start slowing down from highway speeds and sometimes it goes away speeding up again. I don't get any noises at lower speeds. It usually starts after a long drive at higher speeds.

__________________
DJ


84 300D Turbodiesel 190K with 4 speed manual sold in 03/2012

I wondering if it will cause any serious harm to keep driving it like it is? I'm thinking I'll find out for sure what part is going out exactly but I don't want to get stranded somewhere and end up needing to tow the car home. I've been driving it like that with the noise and it seems to occur more frequently and its a bit unnerving
I do have the 230CE to drive now but I still have to change over the title and get it insured.

__________________
DJ


84 300D Turbodiesel 190K with 4 speed manual sold in 03/2012

change the diff lube to synthetic and see what happens. This is the cheapest thing to do, and you are probably due anyway.

peter

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1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!

My 300DT begins to whine at about 50 mph and begins to fade away at about 55 mph. It will get louder if I accelerate within this 5 mph range.

I changed the differential oil to Mobile 1, synthetic differential gear lube and there was no change in whine!

I never thought to check oil in the diff. In fact I don't think I've checked it since I got the car. Good thing it's an easy thing to check.

__________________
DJ


84 300D Turbodiesel 190K with 4 speed manual sold in 03/2012