Low whine/whistle while rolling - PeachParts Mercedes-Benz Forum

JEBalles · #1 05-19-2010, 10:25 AM

I've got a low whine/whistle noise going on while the car ('83 240D) is rolling. It seems rather intermittent. Seems to be most consistent/loudest at 25-30 mph, but not always. 35 mph I didn't hear anything. Definitely not engine-related. Sounds like it's coming from the front. Wheel bearings? Brakes? Transmission maybe? Everything else is fine. Is it still safe to drive?

rummur · #2 05-19-2010, 10:27 AM

no

what if it is a bearing.. could melt the race, and the hub could come off driving down the road.

JEBalles · #3 05-19-2010, 10:45 AM

I just noticed it today, can I drive it the 5 miles home?

rrgrassi · #4 05-19-2010, 10:53 AM

If you can, raise up the front end and spin the wheels and check for bearing play. 5 miles may not seem like much, but anything can happen. If you take it really easy and slow you may should be able to make it.

Oracle12345 · #5 05-19-2010, 10:58 AM

to check for a bad wheel bearing turn off the radio etc and listen carefully to each side as you accelerate. if you think its a tire problem it will go away when you turn go faster however a bad wheel bearing will not. slowly accelerate and turn both wheels if you still hear it then its a wheel bearing. also rasie the car and spin the wheel hard and make sure its smooth and theres no play

vstech · #6 05-19-2010, 11:02 AM

when it's whining, can you touch the brakes and make it stop? or do the brakes intensify the noise? pull the wheels, and see if the brakes are worn, pull the pads, and then put the wheels back on, spin the tires, see if you can hear the noise.
grab the wheels top and bottom, and see if you can feel play. if you can, you have bearing issues.

JEBalles · #7 05-19-2010, 11:15 AM

Alright, called my dad (been working on cars since the 70's) he told me to jack up the car and spin the wheels and listen for any noises. I did and didn't hear anything besides the brake noise (pads resting against rotors). He also said it's safe to drive home.

I recently (in past 6 months/3,000 miles) inspected and repacked the left front bearings, so I don't think it's that.

If I recall correctly, the brakes did not affect the noise, which rules out brakes, I guess. When I'm checking for play, I check parallel to the axle, right? If so, I didn't feel any play.

Didn't sound like a tire problem. Didn't sound like acceleration affected the noise, only speed.

I will do the brake and turning test again after I get home.

vstech · #8 05-19-2010, 12:06 PM

well if dad's given you the OK, you should be fine, it's on him though.
drive carefully. and when you stop, touch the wheels to see if they are hot.
how did you adjust the endplay when you repacked the bearings?
you could have gotten them too tight, and now they are failing.

JEBalles · #9 05-19-2010, 01:37 PM

Made it home alright, couple notes
-noise did not change while turning
-noise varies in tone/frequency
-braking does not affect it
-after I drove a mile or two (engine up to temp.), noise went away completely
-at one point, I thought that I felt the shifter was vibrating with the noise, but that may have been my imagination
-hubs felt normal

I set them end play without the dial indicator, I used the 1/3 (2/3?) turn method. I'm inclined to think maybe the output shaft bearing on the transmission (although that would suck because I just replaced the damn thing). I'll check the fluid level and report back.

fruitcakesa · #10 05-19-2010, 04:18 PM

I set the endplay like you did and burned out the bearing in 12k miles!
Drove all winter thinking it was my noisy snow tires and when I finally put the summer tires on the noise was a rumble and the 20 mile drive to the repair shop totaslly destroyed them and came within a c-hair of damaging the axle shaft!
Check it out.

JEBalles · #11 05-19-2010, 06:37 PM

Alright, update--not the wheel bearings. Jacked up the rear wheels and put it in gear and had the noise big time. I guess it could be the prop shaft center (hopefully) or the trans. output shaft (f*ck my life). I need to make a tool to check the trans. fluid level. When I swapped trans. about a year ago I just filled it up with whatever auto trans. fluid I had on hand and/or just bought the cheapest stuff and haven't checked it since. Could I have screwed my trans., or is it just a matter of putting in more/thicker stuff?

charmalu · #12 05-19-2010, 11:32 PM

You have a 4-spd manual transmission, why do you need a tool to check the fluid?

crawl under the car, remove the upper plug on the trans. the fluid should be at the bottom of the hole. your finger is the tool. If you don`t see any leaks around the transmission, then it is probably where you filled it last. check anyway.

these transmissions use ATF, a thicker fluid will just give you problem shifting.

grab the driveline and see if there is loosness at the trans and the center bearing/u-joint.

Charlie

JEBalles · #13 05-20-2010, 06:26 AM

The plug takes a 14mm allen key, but the one I have doesn't fit in between the trans body and tunnel, so I gotta go buy a cheap one I can cut up.

I've read threads where people argue about which fluid to put in and which ones make the least noise.

I will check for looseness and check the fluid and report back.

JEBalles · #14 05-20-2010, 10:50 AM

Didn't feel any looseness, although I'm not really familiar with checking.

Checked fluid level--is it possible to have TOO much fluid? Mind you, the car wasn't on a completely level surface, a little lower in the front. When I removed the fill plug, it just came pouring out.

I really hope it's just the center bearing.

JEBalles · #15 05-20-2010, 03:56 PM

And a new development: when running with rear wheels in air, there is a shuddering, rhythmic clunk that appears to come from the differential. Whine still sounds like it's coming from the center. Is this normal for the wheels in the air?