The message to which you are about to reply is shown first. GO TO REPLY FORM



 VIEW    REPLY TO THIS MESSAGE    PRINT   SAVE 

Strange low frequency hum/rumble from under the car, only when coasting. 200 1980

posted by  drj434343 on  Tue May 8 14:00 CST 2012
Author: [PROFILE] [EVERY POST] [THREADS] [BEST POSTS] RSS Feed     [IGNORE ALL POSTS]
last visit: Thu Oct 24 09:46 CST 2013
[RELATED]

1980 242DL, took the car out for a spin after an engine rebuild and noticed a VERY loud hum, low frequency, coming from under the car when coasting around 40 mph. It sounds like something hits a resonance at that speed, because it fills the cabin with what sounds like a subwoofer on max, VERY loud. Generally, if I coast and keep the car in gear it stays quiet, but if I take it out of gear, the sound really amplifies. I haven't heard it while accelerating, and seems to go away below or above around 40 mph.

At first I thought tires, so tried a new set of those with no changes. When I had the car apart for rebuild, I inspected all the u-joints on the drive shaft and everything felt nice and tight. I also have a brand new center shaft bearing, spring, and rubber housing installed.

Seems like it could either be the rear diff or the drive shaft, but I can't figure out which is more likely to tackle given that it only happens when coasting.

Any advice?






USERNAME
Use "claim to be" below if you don't want to log in.
PASSWORD
I don't have an account. Sign me up.
CLAIM TO BE
Use only if you don't want to login (post anonymously).
ENTER CAPTCHA CODE
This is required for posting anonymously.
OPTIONS notify by email
Available only to user accounts.
SUBJECT
MODEL/YEAR
MESSAGE

DICTIONARY
LABEL(S) +
IMAGE URL *
[IMAGE LIBRARY (UPLOAD/SELECT)]

* = Field is optional.

+ = Enter space delimited labels for this post. An example entry: 240 muffler


©Jarrod Stenberg 1997-2022. All material except where indicated.


All participants agree to these terms.

Brickboard.com is not affiliated with nor sponsored by AB Volvo, Volvo Car Corporation, Volvo Cars of North America, Inc. or Ford Motor Company. Brickboard.com is a Volvo owner/enthusiast site, similar to a club, and does not intend to pose as an official Volvo site. The official Volvo site can be found here.