What could this noise be???
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Registered User
Joined: Feb 2010
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From: Virginia
What could this noise be???
Here's the description of the noise. It sounds like a whining that varries with speed. It doesn't make the noise when I'm gliding with my foot off the gas pedal. It only seems to do it when my foot is on the gas pedal at cruising speed. I can't seem to hear it when accelerating either. I have a 318 with an automatic transmission and 4WD. I know it's not tire noise, but what could it be?
Champion
Joined: May 2008
Posts: 4,839
Likes: 5
From: Apex, NC
Probably one of these two...
GEAR NOISE
Axle gear noise can be caused by insufficient lubricant.
Incorrect backlash, tooth contact, or worn/damaged
gears can cause noise.
Gear noise usually happens at a specific speed
range. The range is 30 to 40 mph, or above 50 mph.
The noise can also occur during a specific type of
driving condition. These conditions are acceleration,
deceleration, coast, or constant load.
When road testing, 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, check for insufficient
lubricant. Incorrect ring gear backlash, or
gear damage can cause noise changes.
Differential side and pinion gears can be checked
by turning the vehicle. They usually do not cause
noise in straight-ahead driving. These gears are
loaded during vehicle turns. If noise does occur during
vehicle turns, the side or pinion gears could be
worn or damaged. A worn pinion gear mate shaft can
also cause a snapping or a knocking noise.Incorrect backlash, tooth contact, or worn/damaged
gears can cause noise.
Gear noise usually happens at a specific speed
range. The range is 30 to 40 mph, or above 50 mph.
The noise can also occur during a specific type of
driving condition. These conditions are acceleration,
deceleration, coast, or constant load.
When road testing, 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, check for insufficient
lubricant. Incorrect ring gear backlash, or
gear damage can cause noise changes.
Differential side and pinion gears can be checked
by turning the vehicle. They usually do not cause
noise in straight-ahead driving. These gears are
loaded during vehicle turns. If noise does occur during
vehicle turns, the side or pinion gears could be
worn or damaged. A worn pinion gear mate shaft can
BEARING NOISE
The axle shaft, differential and pinion gear bearings
can all produce noise when worn or damaged.
Bearing noise can be either a whining, or a growling
sound.
Pinion gear bearings have a constant-pitch noise.
This noise changes only with vehicle speed. Pinion
bearing noise will be higher because it rotates at a
faster rate. Drive the vehicle and load the differential.
If bearing noise occurs the pinion rear bearing is
the source of the noise. If the bearing noise is heard
during a coast, front bearing is the source.
Worn, damaged differential bearings usually produce
a low pitch noise. Differential bearing noise is
similar to pinion bearing. 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.
can all produce noise when worn or damaged.
Bearing noise can be either a whining, or a growling
sound.
Pinion gear bearings have a constant-pitch noise.
This noise changes only with vehicle speed. Pinion
bearing noise will be higher because it rotates at a
faster rate. Drive the vehicle and load the differential.
If bearing noise occurs the pinion rear bearing is
the source of the noise. If the bearing noise is heard
during a coast, front bearing is the source.
Worn, damaged differential bearings usually produce
a low pitch noise. Differential bearing noise is
similar to pinion bearing. 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.level. Where axle bearing damage is slight, the noise
Is it high pitched and sounding like it's coming from behind you in the cab?
If so, I would say that it's the valve body on the transmission. Mine does it too, and I'm just waiting for an issue to arise out of it. It might also be the gears, but I would think that they would do that all the time and not just at cruising speed.
If so, I would say that it's the valve body on the transmission. Mine does it too, and I'm just waiting for an issue to arise out of it. It might also be the gears, but I would think that they would do that all the time and not just at cruising speed.
Thread Starter
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Registered User
Joined: Feb 2010
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From: Virginia
Is it high pitched and sounding like it's coming from behind you in the cab?
If so, I would say that it's the valve body on the transmission. Mine does it too, and I'm just waiting for an issue to arise out of it. It might also be the gears, but I would think that they would do that all the time and not just at cruising speed.
If so, I would say that it's the valve body on the transmission. Mine does it too, and I'm just waiting for an issue to arise out of it. It might also be the gears, but I would think that they would do that all the time and not just at cruising speed.
Record Breaker
Joined: Dec 2006
Posts: 1,366
Likes: 1
From: Englewood, CO
Here we go...
Does it happen in both 2wd and 4wd?
Does it happen in Reverse?
Does it happen or change when steering?
What about at full steering lock?
What year is your truck?
Is it a 1/2, 3/4, 1 ton?
Does it have a two-piece rear drive shaft?
Is the noise coming from the front?
Is the noise coming from the left or right side?
Have you popped the hood and pulled your accelerator cable to see if it happens there?
Is it a grinding noise? An intermittent squeaking noise? Something scraping?
From what I can tell, your bed springs are worn and need to be replaced. Go to the store and tell them you need new bed springs. Make sure you get the green ones since they have a higher spring rate than the blue or gold.
Does it happen in both 2wd and 4wd?
Does it happen in Reverse?
Does it happen or change when steering?
What about at full steering lock?
What year is your truck?
Is it a 1/2, 3/4, 1 ton?
Does it have a two-piece rear drive shaft?
Is the noise coming from the front?
Is the noise coming from the left or right side?
Have you popped the hood and pulled your accelerator cable to see if it happens there?
Is it a grinding noise? An intermittent squeaking noise? Something scraping?
From what I can tell, your bed springs are worn and need to be replaced. Go to the store and tell them you need new bed springs. Make sure you get the green ones since they have a higher spring rate than the blue or gold.
Thread Starter
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Registered User
Joined: Feb 2010
Posts: 11
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From: Virginia
Here we go...
Does it happen in both 2wd and 4wd? Haven't checked 4WD yet.
Does it happen in Reverse? Haven't checked while in reverse over 20 MPH at 5 to 10 MPH in reverse it doesn't seem to be there.
Does it happen or change when steering? Seems the same
What about at full steering lock?
What year is your truck? 1998
Is it a 1/2, 3/4, 1 ton? 1/2 Ton
Does it have a two-piece rear drive shaft? 1 piece
Is the noise coming from the front? Seems like the rear
Is the noise coming from the left or right side?
Have you popped the hood and pulled your accelerator cable to see if it happens there? Not yet.
Is it a grinding noise? An intermittent squeaking noise? Something scraping? It sounds like a whining that varries with speed. It doesn't make the noise when I'm gliding with my foot off the gas pedal. It only seems to do it when my foot is on the gas pedal at cruising speed.
Does it happen in both 2wd and 4wd? Haven't checked 4WD yet.
Does it happen in Reverse? Haven't checked while in reverse over 20 MPH at 5 to 10 MPH in reverse it doesn't seem to be there.
Does it happen or change when steering? Seems the same
What about at full steering lock?
What year is your truck? 1998
Is it a 1/2, 3/4, 1 ton? 1/2 Ton
Does it have a two-piece rear drive shaft? 1 piece
Is the noise coming from the front? Seems like the rear
Is the noise coming from the left or right side?
Have you popped the hood and pulled your accelerator cable to see if it happens there? Not yet.
Is it a grinding noise? An intermittent squeaking noise? Something scraping? It sounds like a whining that varries with speed. It doesn't make the noise when I'm gliding with my foot off the gas pedal. It only seems to do it when my foot is on the gas pedal at cruising speed.
Record Breaker
Joined: Dec 2006
Posts: 1,366
Likes: 1
From: Englewood, CO
Do you know what the fuel pump sounds like? If so, do you think that could be it? If not, with it in park and the wheels blocked have someone start the truck with you under it. Listen for the noise. Then have them slowly press on the gas and see if you hear it raise in pitch or get louder.
My next guess is a bearing or rear u-joint.
How many miles are on the truck? Any recent fluid changes?
My next guess is a bearing or rear u-joint.
How many miles are on the truck? Any recent fluid changes?
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Professional
Joined: Mar 2007
Posts: 242
Likes: 0
From: Lakeland TN
I've noticed the same whine in mine (360 with 46RE) and it will stop once I depress the overdrive button (thereby taking it out of OD and into 3rd gear).
That being said, I'm pretty sure it's OD related.
Try the taking the tranny in/out of OD and report back.
That being said, I'm pretty sure it's OD related.
Try the taking the tranny in/out of OD and report back.
Grand Champion
Joined: Apr 2008
Posts: 7,055
Likes: 7
From: Lee County, North Carolina
It is sounding like a transmission issue since it doesn't do the noise when you are coasting.
Does is sound like the videos on this thread? https://dodgeforum.com/forum/2nd-gen...-rear-end.html
That turned out to be a bad pinion bearing in the rear end.
Does is sound like the videos on this thread? https://dodgeforum.com/forum/2nd-gen...-rear-end.html
That turned out to be a bad pinion bearing in the rear end.