Rear End Noise

[glav]

Got 37K miles on my truck and am starting to hear a noise from what I think, is the rear end (AAM 11. 5). It sounds like the tires are going sideways on gravel. I hear is mostly when I start up from a dead stop and turn either right or left, pulling a heavy fifth wheel. Never hear the noise when pulling straight ahead. Also don't hear it much when driving solo (without the trailer). Dealer said that with the Trac-Rite that is normal, got a "Tech Tip #20". Has anyone else had such an experience? Would appreciate your comments.

Many Thanks

Gene

 

[rbattelle]

The noise as you describe it sounds almost like a light grinding. And since it's doing it under load, that could mean trouble. What axle fluid are you running, and how often have you been changing it?

 

[glav]

I had changed the fluid at 15K miles using AMSOIL 75W-90. With 37K I was a little overdue for the next change. Well today I had the oil changed and had the shop check out the rear wheel bearing and then we checked the pinin and differential gears, all were OK. We also checked the gear wear pattern on the teeth and they seemed to be OK. Now we checked them without the trailer, so need to figure a way to check under this size of load. The old oil looked good and there we no evidence of metal in it. So I am getting to move the trailer again next week, so will be very focus on how we handle the turns. Fortunately, I checked with a local Dodge dealer and they claim that the rear differenial is considered part of the power train and I still have warrantly left on that, but want to get this resolved as soon as possible

Thanks for your help

Gene

 

[draymorris]

I had the same as you describe, except I felt it more than heard it - under load only - on corners and taking off. The big difference is that I had a lot of metal in my fluid. I also run amsoil - the oil will not cause this problem and don't let anyone tell you there are supposed to be friction modifiers in the oil - these are clutch-less rear ends so friction modifiers are not needed.



The dealer replaced my entire rear end the first time and then the ring and pinion 10 k later because the bearinigs became loose. They told me that they could NOT see unusual wear on the gears - even after they removed the assy, but the amount of metal was enough to replace it. This is NOT normal unless they are just saying that the failure is normal. I know my technician, and he has told me that these trucks are coming in a bunch for this problem. It is in the anti spin (if that is the right term) gears.



After the Ring and Pinion they told me that the whine in 6th that I hear is just resonance coming up the drive train into the transmission from the rear end. Mine does seem to act right now so I will just tolerate the slight whine in 6th.

Good luck