I am done with the suspension, now on to the drivetrain. I am getting what would be best described as a whinning/droan sound when I let up on the accelerator. There is no clunk when I back off of the pedal, but there is a noticeable sound that is directly related to speed. In that as you come to stop, the sound "slows" down. I have had the rear differential fluid changed, so it's not a matter of old gear oil. While cruising, if I get off the pedal and then get back on it slowly there is no "clink". However if I get back on the pedal quickly there is some "clunking", but I imagine there is to be some expected in a 21 year old car. It's the decelerating whinning sound I am concerned about, or is this fairly common and is nothing to be too concerned about. There is no whinning while accelerating.
Thanks.

__________________
1999 MB SL500 (110,000 mi)
2004 Volvo V70 2.5T (220,000 mi)
2014 Tesla Model S 85 (136,000 mi)
MBCA member

Anyone?

__________________
1999 MB SL500 (110,000 mi)
2004 Volvo V70 2.5T (220,000 mi)
2014 Tesla Model S 85 (136,000 mi)
MBCA member

Greetings Rick,

No professional at drive train matters but have had similar problems with gas driven drive trains and maybe they are somewhat on the same lines for troubleshooting. In one case my rear wheel bearing were coming apart, prepacked of course and unserviceable, so replacement was the only option, Ford's better idea I guess, but they only whined while coasting or while in a slow braking mode. The other experience was when the preload on my driveshaft was tightened incorrectly by the dealership after a front differential seal replacement, and it almost chewed up my pinion gear before it got resolved. Same problem there as well, only made sound during deccelleration or slow braking, none during acceleration. On these old Benz's I think I would personally look at the wheel bearings first to make sure they are intact and running grease then I'd move on to driveshaft to differential problems. It could also be as easy as a slipped steel belt on your tires if the sound is predominant at a certain speed consistantly.


Charles

Thanks for the idea about checking the rear wheel bearings. I know what you mean about Ford's wheel bearings, we once owned a '93 Taurus and everything on that car seemed to be designed to be replaced, not repaired. That's what I like about my Benz. Everything is either screwed or bolted together, so it can be taken apart by hand.
The noise, like I said, is only while coasting when I let off the accelerator. It is more pronounced at speeds below 40 mph. When I first started noticing the noise, I didn't know whether it was normal or not. It has been 10 years since I have owned a rear wheel drive car.

__________________
1999 MB SL500 (110,000 mi)
2004 Volvo V70 2.5T (220,000 mi)
2014 Tesla Model S 85 (136,000 mi)
MBCA member