1985 300D Turbo. If I drive 15 or 20 miles everything is fine. No rear end noise. So all winter was fine since all trips 20 miles or less. This past summer and autumn I heard a rear end noise after 30 miles or so. Let the car rest and hopefully the car would return to normal, and then attempt a trip back home. Had flex discs and center bearing changed as well as rear sway bar links. Didn't fix.The boots are old, the outer boots have a crack but none have any leaks. Noise goes away as soon as mechanic hops in the car.
I want to try to note whatever might help diagnose the cause of the noise. I'm thinking CV joints but would like some evidence before replacing. The half axles have a small amount of play but he says he has nothing to compare it to and his Mercedes contact says probably expect some play even when new.
What driving tests can I perform when I get the noise?
Quick acceleration or deceleration?
Car in neutral and listen while coasting indicate anything?
Any particular type of noise incriminate differential? CV joints?
Maybe I'll try to hook up a cheap compact voice recorder under the car with the ON switch rewired with a long wire to the interior of the car. Then let him listen. Maybe I'll figure out how to get the recording on this forum. A lot of you guys can probably associate various car noises with problem parts. I can't. Might be a helpful thread (Various noise recordings vs probable cause)
Thanks in advance for any suggestions and all past help.
Joe

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1985 300D Turbo
"Evolution is God's way of giving upgrades" Francis Collins

"I hear a rear end noise after driving a bit" isn't much decription to go on.

Can you give a description of the noise? Whining bearing? Gear whirring? Rumble? Whistling? Clunk? Rubbing? Grinding? Screech? Metal-on-metal? Does it sound like something else we might know the sound of too?

Also, is there a pattern to it beyond drive for a distance? Only when accellerating? coasting? Decellerating? Does it change with temperature? Speed? Road surface? And, of course, the ever popular, can you cause it to happen on demand? Try some experiments to see if you can cause the noise to change.

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'83 300DTurbo http://badges.fuelly.com/images/smallsig-us/318559.png

Broadband: more lies faster.

Thank you patbob. Yeah occasionally I do need to have the obvious stated to me. Now I'm motivated to go out and get that noise again. This time I'll try to listen carefully. Its happened a number of times but I must get distracted because I just can't remember it exactly. I do remember the car behind me giving plenty of space though.

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1985 300D Turbo
"Evolution is God's way of giving upgrades" Francis Collins