humming noise from rearend?

[azkid]

Guys,

My 04 hemi (2WD) has 3.55 gears and 21500 miles on the odo. When accelerating from 45 – 75, I hear a noticeable hum that I think is coming from the rear axle. The noise goes away after 75, and then comes back at 90 – 110. If I release the gas, the noise goes away. Has anyone experienced this?

Thanks,

azkid

[dodgeatheart]

Make sure you get your rear diff fluid changed, then take it back to the dealership - it sounds as though you might be losing your rear (and no, I'm not referring to a bad outing of Mexican).

[Chuck_IV]

This could be the exhaust drone that lots of people have talked about here. People talk about the vibration mainly, but there is also a low pitched hum/sound that comes along with it.

[Big3]

Make sure to read the TSB about filling the rear end about an inch below the fill hole and not up to it.

[TheSeer]

Does anyone know the TSB about not filling the rear end to the top? I'm having my diff's done in a few days and want to make sure they do it correctly....

[Big3]

I asked my dealer's service mgr about changing the rear diff fluid and if it really needed it at 15k miles. He said it sure does - it needs to be cleaned out and some posi trac additive added to the lube. I didn't think it had posi-trac. Is this true?

[TheSeer]

There is no posi-trac offered - only "traction control" which is accomplished through the brakes. My dealer gave me the bit about the posi-trac additive - when i challenged him about the need for additive since it doesn't have a locking differential, he changed the story. Said they still put the same additive in, but it has a different label on the can. I didn't buy the story and had the work done elsewhere. EXCEPT....they didn't get the rear plate sealed and I'm going to have to take it back to have it redone. :mad:

[whatup]

TECHNICAL SERVICE BULLETIN: MFG Bulletin Number: 1801404

MFG Bulletin Date: 20040525

Component: POWER TRAIN:AUTOMATIC TRANSMISSION:CONTROL MODULE (TCM, PCM)

Details: 42RLE SLOW OR HARSH GEAR ENGAGEMENT AFTER INITIAL COLD START. *TT *MJ

Internal use: 20040506


Check to include on Custom Report
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Create Custom Report TECHNICAL SERVICE BULLETIN: MFG Bulletin Number: 1803303

MFG Bulletin Date: 20040302

Component: POWER TRAIN:AUTOMATIC TRANSMISSION:CONTROL MODULE (TCM, PCM)

Details: GENERIC POWER TRAIN CONTROL MODULE (PCM) FLASH PROCEDURE. 2004 DURANGO. *TT *MJ

Internal use: 20031110


Check to include on Custom Report
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Create Custom Report TECHNICAL SERVICE BULLETIN: MFG Bulletin Number: 0300104

MFG Bulletin Date: 20040113

Component: POWER TRAIN:AXLE ASSEMBLY

Details: THE AXLES ARE LOCATED CONSIDERABLY HIGHER THAT THE ACTUAL FLUID LEVEL. FILLING THE AXLE UNTIL THE FLUID COMES OUT OF THE FILL HOLE WILL OVER FILL THE AXLE, WHICH COULD CAUSE FLUID FOAMING. *MN

Internal use: 20040303


Check to include on Custom Report
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Create Custom Report TECHNICAL SERVICE BULLETIN: MFG Bulletin Number: 04004

MFG Bulletin Date: 20040226

Component: POWER TRAIN:AXLE ASSEMBLY

Details: CERTAIN 2004 TRUCKS EQUIPPED 8-1/4 IN. OR 9-1/4 IN. REAR AXLES MAY HAVE BEEN BUILT WITH CONTAMINATED AXLE FLUID. RAPID RESPONSE TRANSMITTAL SUPPLEMENT A. *TT

Internal use: 20040406


Check to include on Custom Report
--------------------------------------------------------------------------------
Create Custom Report TECHNICAL SERVICE BULLETIN: MFG Bulletin Number: 04004

MFG Bulletin Date: 20040226

Component: POWER TRAIN:AXLE ASSEMBLY

Details: CERTAIN 2004 TRUCKS EQUIPPED 8-1/4 IN. OR 9-1/4 IN. REAR AXLES MAY HAVE BEEN BUILT WITH CONTAMINATED AXLE FLUID. RAPID RESPONSE TRANSMITTAL. *TT

Internal use: 20040406


Check to include on Custom Report
--------------------------------------------------------------------------------
Create Custom Report TECHNICAL SERVICE BULLETIN: MFG Bulletin Number: 0300104A

MFG Bulletin Date: 20040511

Component: POWER TRAIN:AXLE ASSEMBLY

Details: THE AXLES ARE LOCATED CONSIDERABLY HIGHER THAT THE ACTUAL FLUID LEVEL. FILLING THE AXLE UNTIL THE FLUID COMES OUT OF THE FILL HOLE WILL OVER FILL THE AXLE, WHICH COULD CAUSE FLUID FOAMING. *MN *TT

Internal use: 20040303

[whatup]

I just checked with my dealer on the diff service. $150 for rear and $100 for front. I asked if there was an additive for the rear and the service adviser said "Yes". I than stated it was to much for me to have them do it. He said I could do it, just to keep all receipts and be sure to right down mileage on receipts. Said that they have seen warranties denied because mileage was not noted. I went to the parts department and asked what all fluids I needed. He didn't mention a limited slip added that the service department stated I needed. I told him that they just told me a needed to purchase this. He called service and asked what they were talking about. The service adviser stated that they always put an added in because most of dodge vehicle require it. The parts manager stated he wont sale anything I don't need and because my D has opened diffs I didn't need it. I have read in another post that someone else was questioning this additive. This is what I was told. I also had my service Mgr note on my last invoice that using my own lubricant and performing the service myself will not void any warranty.

Just thought I would share.

[TheSeer]

I think some of the service writers are ignorant and don't know what they're talking about. The svc writer at the dealer told me the same thing about them putting in an additive. When I challenged him on it, he changed his story to say they still put one in, it was the same thing, but with a different name and label. He also tried to convince me tow-haul is not supposed to provide engine braking (in 3rd gear) at closed throttle etc. - that the only engine braking you get is 45mph and below if you have the tranny shifted into 2nd gear. I'm getting tired of educating someone who should already be an informed "expert".

[DurangoGuy123]

wondering if the humming only occurs during light acceleration.. i have an 05 and when driving on the highway and slightly pressing the gas i get a humming sound.. if i get off the gas it goes away and if i floor it i dont hear it... thanks