howling noise...help please
Thread Starter
Staging Lane
Joined: Jun 2009
Posts: 59
Likes: 0
From: Pinson, Alabama
howling noise...help please i have a odd howling noise coming from the rear of my car. its only noticable at about 40 to 50 mph with light throttle. axle/wheel bearing or rear end?
i also have a rattle at my front left tire...sounds like a ball joint coming loose but ball joints are fine. strut tower maybe?
i also have a rattle at my front left tire...sounds like a ball joint coming loose but ball joints are fine. strut tower maybe?
12 Second Club
Joined: Nov 2005
Posts: 407
Likes: 1
From: Rockwall, TX
DIAGNOSIS AND TESTING
GEAR NOISE
Axle gear noise can be caused by insufficient lubricant,
incorrect backlash, incorrect pinion depth, tooth
contact, worn/damaged gears, or the carrier housing
not having the proper offset and squareness.
Gear noise usually happens at a specific speed
range. The noise can also occur during a specific type
of driving condition. These conditions are acceleration,
deceleration, coast, or constant load.
When road testing, first warm-up the axle fluid by
driving the vehicle at least 5 miles and then accelerate
the vehicle to the speed range where the noise is
the greatest. Shift out-of-gear and coast through the
peak-noise range. If the noise stops or changes
greatly:
² Check for insufficient lubricant.
² Incorrect ring gear backlash.
² Gear damage.
Differential side gears and pinions can be checked
by turning the vehicle. They usually do not cause
noise during straight-ahead driving when the gears
are unloaded. The side gears are loaded during vehicle
turns. A worn pinion shaft can also cause a snapping
or a knocking noise.
BEARING NOISE
The axle shaft, differential and pinion bearings can
all produce noise when worn or damaged. Bearing
noise can be either a whining, or a growling sound.
Pinion bearings have a constant-pitch noise. This
noise changes only with vehicle speed. Pinion bearing
noise will be higher pitched because it rotates at a
faster rate. Drive the vehicle and load the differential.
If bearing noise occurs, the rear pinion bearing
is the source of the noise. If the bearing noise is
heard during a coast, the front pinion bearing is the
source.
Worn or damaged differential bearings usually produce
a low pitch noise. Differential bearing noise is
similar to pinion bearing noise. The pitch of differential
bearing noise is also constant and varies only
with vehicle speed.
Axle shaft bearings produce noise and vibration
when worn or damaged. The noise generally changes
when the bearings are loaded. Road test the vehicle.
Turn the vehicle sharply to the left and to the right.
This will load the bearings and change the noise
level. Where axle bearing damage is slight, the noise
is usually not noticeable at speeds above 30 mph.
GEAR NOISE
Axle gear noise can be caused by insufficient lubricant,
incorrect backlash, incorrect pinion depth, tooth
contact, worn/damaged gears, or the carrier housing
not having the proper offset and squareness.
Gear noise usually happens at a specific speed
range. The noise can also occur during a specific type
of driving condition. These conditions are acceleration,
deceleration, coast, or constant load.
When road testing, first warm-up the axle fluid by
driving the vehicle at least 5 miles and then accelerate
the vehicle to the speed range where the noise is
the greatest. Shift out-of-gear and coast through the
peak-noise range. If the noise stops or changes
greatly:
² Check for insufficient lubricant.
² Incorrect ring gear backlash.
² Gear damage.
Differential side gears and pinions can be checked
by turning the vehicle. They usually do not cause
noise during straight-ahead driving when the gears
are unloaded. The side gears are loaded during vehicle
turns. A worn pinion shaft can also cause a snapping
or a knocking noise.
BEARING NOISE
The axle shaft, differential and pinion bearings can
all produce noise when worn or damaged. Bearing
noise can be either a whining, or a growling sound.
Pinion bearings have a constant-pitch noise. This
noise changes only with vehicle speed. Pinion bearing
noise will be higher pitched because it rotates at a
faster rate. Drive the vehicle and load the differential.
If bearing noise occurs, the rear pinion bearing
is the source of the noise. If the bearing noise is
heard during a coast, the front pinion bearing is the
source.
Worn or damaged differential bearings usually produce
a low pitch noise. Differential bearing noise is
similar to pinion bearing noise. The pitch of differential
bearing noise is also constant and varies only
with vehicle speed.
Axle shaft bearings produce noise and vibration
when worn or damaged. The noise generally changes
when the bearings are loaded. Road test the vehicle.
Turn the vehicle sharply to the left and to the right.
This will load the bearings and change the noise
level. Where axle bearing damage is slight, the noise
is usually not noticeable at speeds above 30 mph.
Last edited by 91RS383; Nov 4, 2009 at 03:10 PM.
Thread Starter
Staging Lane
Joined: Jun 2009
Posts: 59
Likes: 0
From: Pinson, Alabama
Thanks alot david. i think it might be my rear end goin out on me cause about two weeks ago i was racin this mustang and i missed 4th BAD and ever since then ive noticed the noise. seems to be slowly getting worse too.
and is there anyway to diagnose the sway bar bushings?
and is there anyway to diagnose the sway bar bushings?
12 Second Club
Joined: Nov 2005
Posts: 407
Likes: 1
From: Rockwall, TX
find out what makes the noise when sitting still. Moving the steering wheel? Jouncing the bumper? Then have someone repeat that motion while you crawl under the nose and listen, observe.
The Sway bar should be tight at all conection points.
The Sway bar should be tight at all conection points.
