I just bought a new Quad Cab 4X4 and hear a rear-end whine at highway speeds. Older traded 99 2500 LWB and never heard a whine - but then again, the engine was a lot noisier, so maybe this is normal. Noise stops when I let off pedal.

 

Sounds like a bad pinion bearing to me. Had a lifted Jeep cherokee that had this same issue. I think its your front pinion bearing if it howls when youre on the gas and your rear bearing if it howls when your off the gas.

 

Have you checked the fluid levels in both differentials?

The '03's are notoriuous for being underfilled from the factory.

Know of one guy who had his rear replaced under warranty due to it being underfilled.
(Can't remember if it's SierraPhil or FiverBob, I always get those two confused )


phox

 

Phox<br><br>Pretty easy to get those two confused all righty, they both are senile and forget where they hid the key to the 5th wheel!<br><br>Heck, BobWhite is still dreaming of an almond truck and Sierra is thinking he had his rear end replaced but it still &quot;hoot&quot; once in a bit! <br><br> ;D<br><br>Hunter

 

[quote author=nailzsn link=board=20;threadid=14973;start=0#140419 date=1053480852]
I just bought a new Quad Cab 4X4 and hear a rear-end whine at highway speeds. Older traded 99 2500 LWB and never heard a whine - but then again, the engine was a lot noisier, so maybe this is normal. Noise stops when I let off pedal.
[/quote]


From 2003 Ram Truck Service Manual:
REAR AXLE - 11 1/2 AA
DIAGNOSIS AND TESTING
GEAR NOISE

Axle gear noise can be caused by insufficient lubricant, ncorrect 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.

Sure sounds like the rear pinion bearing. They should replace the ring and pinion gears, and both pinion bearings. The should also disassemble a Trac-Rite Differential, clean and inspect components as per service manual. The Trac-Rite differential cannot be repaired, no replacement parts, but must be replaced as a unit.

Also from 2003 Ram Truck Service Manual:
Page 3 - 146 REAR AXLE - 11 1/2 AA DR
DIFFERENTIAL TRAC-RITE (Continued)
INSPECTION
NOTE: Minor corrosion, nicks or scratches can be smoothed with 400 grit emery cloth and polished out with crocus cloth.
(1) Inspect pinion gears teeth for chips and cracks (Fig. 42).
(2) Inspect pinion gears shafts and brake shoes for scratches,
flat-spots or worn (Fig. 42).
(3) Inspect side gears teeth for chips and cracks (Fig. 43).
(4) Inspect pinion and side gear bores for scratches (Fig. 44).
NOTE: If any damage is found the differential must be replaced as an assembly. Individual components can not be replaced separately.

I hope this helps. I don't believe the Tech who replaced my ring and Pinion gear and bearings cleaned and inspected my Trac-Rite Diff. It now seems to grab on turns below 15-20 mph, giving a definite jerk going around corners.

Hope this info helps.

BeenThereDoneThatPhil

 

Holycack, phox mulder, sierra phil, hunter.<br><br>Thanks for the input. The truck has less than 500 miles on it and is sitting home waiting for me to get there from traveling. I will check the fluid levels (front and back) first and then pinpoint exact speeds at which noise is evident. I believe it was above 50 mph when I noticed it, but I will check for sure on Friday. I plan on towing in about 3 weeks so I would like to have this resolved. Thanks again.

 

i HAVE THE WHINE TOO it seems.<br><br>I think I mentioned it a while ago and thought it was the tranny tailshaft bearing or something to do with the cut of 6th gear.<br><br>Altogether I am not too sure.<br><br>But on the other hand it isn't getting worse.

 

I had the ring and pinion replaced on my truck at 6500 miles.It would howl or whine at about 68-70mph.I took it in and had it checked.They replaced the gears no questions asked.<br><br> mike b<br>

 

dmdbit, hope they replaced pinion bearings. They should put new Pinion bearings with new R&amp;P gears, as bearings are usually shot and the whiners.

 

I get a howl between 50 &amp; 55 when my 48RE kicks into ODrive....I also checked the differential and it was low about a quart and it felt like it was dragging the truck down.....<br>Filled it with specified lube and feels real smooth and not dragging......but still with the howl.....

 

Rear axle whines/howls will only get worse with more miles. Have it checked under warranty. It is a real safety issue. REMEMBER WANTABEE! His axle had bearing lock up and twisted rear axle apart at 70 mph. Damaged his auto tranny and drive shaft, and who knows what else. Having a work order which shows you reported a problem to dealer, erases the question of possible negligence on your part and shifts it to Dodge should there be a failure. 50-55 mph is when pinion drive bearing noise becoume really audible. Don' hesitate on a safety issue.

 

I started this thread less than a week ago - have been traveling (not in my truck), back now and checked the truck out. Here's the scoop. I begin to hear the whine at about 55mph, but very light. Then it starts in louder at about 63mph and gets louder to about 70mph. I have not taken it faster than that. At all speeds, when I let off the pedal, the whine stops until the pedal is pressed again. The front axle is about 1/2&quot; low. My manual says 1/4&quot; +- 1/4&quot; below hole -so that one is on the edge. The rear (11.5) axle is about 1&quot; below the fill hole. My manual says 1/4&quot; +- 1/4&quot; below hole on the Rear 11.5. I've read other info on this and other forums that says 3/4 to 1&quot; below fill is acceptable. What do you guys think. Could this much low cause the whine?

 

I When I filed the differential I wiped the plug off because there was about 1/3&quot; of shavings on the magnet I then took it too the dealer about two weeks later and they said I destroyed the evidence : Hell I didnt want too drive around all day with a differential that had low fluid and its my only vehicle

I have a maiden voyage this weekend of about 300 miles, so we'll se how it goes (she's only got 1,800 miles)

 

[quote author=Sierra Phil link=board=20;threadid=14973;start=0#141861 date=1053856385]<br>Rear axle whines/howls will only get worse with more miles. Have it checked under warranty. It is a real safety issue. REMEMBER WANTABEE! His axle had bearing lock up and twisted rear axle apart at 70 mph. Damaged his auto tranny and drive shaft, and who knows what else. Having a work order which shows you reported a problem to dealer, erases the question of possible negligence on your part and shifts it to Dodge should there be a failure. 50-55 mph is when pinion drive bearing noise becoume really audible. Don' hesitate on a safety issue.<br>[/quote]

 

Update after taking to dealer. Tech said the whine was not normal and said bearings must be replaced. He said Dodge may want to replace all the gears, but is not sure. I explained that the fluid was 1&quot; low and the book says 1/4&quot; below fill hole. He said fluid looked OK since he was able to touch it with his pinky. It seems to me that my method of using a small tape measure should be more accurate, but he's the techy.