2004 QC LB 2nd REAR END CHANGE IN 1000 MILES

[byoslandry]

My 2004 5. 9L HO 305HP QC AUTO LB SWD (Stock truck) rear end was changed under warranty around 10,000 miles because of a loud hum at 35 mph and again at 70 mph.

I now have about 11,000 miles on the truck and the loud hum is back at 63 mph. Dealer will change rear end this coming week. Again under warranty. Dealer will install a rear end from a new truck that has a few miles on it that he knows does not have a hum in it.

Dealer now admits that they have had a couple of trucks recently (dealer would not admit to this problem on the first rear end change) with rear end noise. They believe the rear end assembly made by American Axles is the cause.

Has anyone else had this problem?

I really like this truck, but I am now glad that I took out that extended warranty because, I feel I might need it right up to the 100,000 mile end.

 

[BarlowCummins]

Do you know which rearend you have? I have the AA 11. 5 because of the 6spd. I think that the autos may have the AA 9. 5. Does anyone know the difference? I don't have the hum, you may want to try changing the fluid in the new one after they change it. I have used a good synthetic in my rearend since 10k and haven't had a problem. Good Luck Corey

 

[DJennings]

I think all CTD's, Manual or Auto, have 11. 5" AAM rear. I think it's a required upgrade with the Cummins. Mine's an auto with 11. 5" axle.

 

[jwduke]

My 04. 5 with the auto shifter, has a 11. 5 too. I agree with the fact, that all Cummins get them.

 

[Vaughn MacKenzie]

I had a hum on my '03 that I thought for sure was the rear end. After upgrading the exhaust it was discovered that was what was causing the hum, even though it did not sound exhaust related at all.



As I read about rear axle replacements I often wonder if they are getting switched out because they're actually bad or because others have the same exhaust hum I did.



Vaughn

 

[catoiler]

I'm on my third and it is starting to make noise again. 28000 miles on it now, first one at 15000 2nd one at 23000. The dealer told me at 1500 miles the noise was normal and not to worry. at 10000 miles it was toast and they were going to call me when the parts came in. at 15000 I called them to ask when the parts would be in and they "forgot"to order them.

 

[byoslandry]

Corey

I don't know what rear end it is, only that it is the 3. 73 ratio. As far as the oil, the dealer put in the factory's synthetic oil after the first rear end change. I will be curious to know, if the dealer figures this out, what causes this.

 

[byoslandry]

Vaughn

I'll mention this exhaust hum to the dealer and see if he will check that out as the cause of the hum.

I would never have thought of this.

Thanks for you input.

Byron

 

[byoslandry]

Catoiler

The dealer told me on the first rear end change that the hum was due to mismatched gears from the factory. Did the dealer tell you what caused your rear end hums after he changed the rear ends?

Three rear ends. I hope I don't have to go through that.

I just want a dependable truck.

Byron

 

[DPKetchum]

Well if dealer was replacing the ring and pinion and tech did not get it set up correctly I could see repeated noise. In the 2. 5 years the 3rd generations have been out I've read very very few problems with the AAM axels. I read two sites daily. Also FOLLOW a easy break in on any differantial. No heavy loads,no high speed etc. for first 500 miles etc. The owners manual break in procedure is set up more for differantials then the engine. Diffs when new create a lot of heat and gears do wear into each other.

 

[byoslandry]

Update On 2004 Ctd 2nd Rear End Change

My 2004 5. 9L HO 305HP QC AUTO LB SWD (Stock truck) rear end was changed under warranty around 10,000 miles because of a loud hum at 35 mph and again at 70 mph.

I now have about 11,000 miles on the truck and the loud hum is back at 63 mph. Dealer will change rear end this coming week. Again under warranty. Dealer will install a rear end from a new truck that has a few miles on it that he knows does not have a hum in it.

Dealer now admits that they have had a couple of trucks recently (dealer would not admit to this problem on the first rear end change) with rear end noise. They believe the rear end assembly made by American Axles is the cause.

Has anyone else had this problem?

I really like this truck, but I am now glad that I took out that extended warranty because, I feel I might need it right up to the 100,000 mile end.

UPDATE ON THIS LATEST REAR END CHANGE

The dealer decided 3/29/2005 to exchange the entire axle assembly from an identical truck with about 3800 miles on it that he knew didn't have any rear end hum in it. I have driven it about 300 miles since that change at about 11,000 odometer miles and can not detect a hum at any speed. For the second rear end change, it took about 800 miles or so before I could detect a hum. . I hope this works as all I want is a dependable truck.

 

[curatchko]

I have the 11. 5", 3. 73 gear. Had mine replaced at 5000 miles for a loud hum at deceleration... now the truck has 35k on it, and it's been back for probably 10k miles... . dealer has it right now not sure what they are planning to do... . maybe I should just accept it since it's not while there is a load, just decel.

 

[DJaquez]

I have had my rear end changed out twice and looking like I will be going in for a thrid time here shortly. Factory rep told me that is normal in SOME of the trucks, I ran up the BS flag and asked it is normal why doesn't it happen in all trucks? He gave me an extended warranty for free. I told him that I still expected my rear end to be fixed.



Here we go for round three. Hate to think that i am looking at the Lemon law.....

 

[JPM]

I have a growl in my rr diff. on deceleration

With less than 34,000 miles, I have a growl in my rr diff. on deceleration. I'm going to the dealer Tues.

 

[CUMMINZ]

rear end noise

I have 2004. 5 with limited slip. When I am towing my 5er and under hard accelleration turning to the left I get a real hard shudder in my truck. Dealer tells me the factory said it was the rearend and it is normal and I said normal my butt.

 

[MCrossley]

I have seen a few trucks come in and out of the dealer with axle issues, however the comment earlier about who set it up has a lot of merrit. Unfortunalty some dealers just let any grease monkey do the job and not someone who is trained to do the setup correctly... . It is not normal for the trucks to hum, however with that said the 70mph vibe seems to have fallen under that category... .

 

[EB]

My truck has "hummed, whined, howled" for 267,000+ miles and is still pulling everyday. I agree with those that say that some rear ends just whine. I check and change my rear axle oil regularly, and until I start finding chunks stuck to my magnet, I'm going to just listen to it. If the noise changes suddenly and drastically, then I'll know something is wrong.

 

[JPM]

Mine has developed the noise within the last few months. Before that it did not have any issues.

 

[catoiler]

Here is some pics of mine after the first rebuild. Notice the junk that was left in it from the last rebuild!He said the bearings were OK and I made them pull the hub and rotor and show me the bearings. Funny how they had no hardness left on the races and the rollers had crap pressed into them. That statement that DP made is very true!If I did work like that at work I would be kicked out on the street. That job they did would never make it past the first oil sample at work. I have 9000 miles on the 05 that Chrysler bought for me and no sign of any problems yet! [/IMG]#ad
[/IMG]#ad

 

[steved]

I think all CTD's, Manual or Auto, have 11. 5" AAM rear. I think it's a required upgrade with the Cummins. Mine's an auto with 11. 5" axle.

The early 3rd gens were a little different.



The SO CTD with the 47RE came with a 10. 50AAM, the HO and 6 spd cam with the 11. 50AAM. After they dropped the 47RE, I believe all the CTDs now have the 11. 50AAM rear and all have the 9. 25AAM front axles.



steved