I recently drove 1800 miles in my '04 1500 Hemi Quadcab, during which the pinion nut came loose and the drive shaft vibrated during coast. Brought it to dealer and they spent an hour installing a redesigned pinion nut and said everything looked good. Returning home for 1800 miles I made it half way and stopped to camp. After about 2 hours parked drove the truck again and the pinion bearing is now humming/singing. Drove the final 900 miles with a very loud high pitched humming noise. Once the problem stated it remained in the same state, it did not get worse. There are no new vibrations accompanied with the noise. The pitch changes with speed and load and it is a high pitched sound. It is the factory gears and LSD.

So my questions are:
Could this just be an adjustment of the nut due to improper torque?
Is there a way to check the torque without ripping the whole rear apart?
If the bearing are shot, would there be any vibration?
Given the earlier loose pinion nut, what are the odd that the bearing is not damaged?
And one tangential question, if I replace the rear gears with a different ratio, can I safely drive the truck in 2wd mode for a week or two until I have time to change the front gears? Would I need to remove the front driveshaft to make this work?

 

I would start with checking the condition of the oil in the differential.
Steve

 

Take it to your local dealer it has a warranty. Sounds like they did not pre load the bearing correctly. Hopefully the change the diff fluid.

 

I did not even think that it would have a warranty. Called the local dealer, they said bring it in and they would inspect it. Going in tomorrow to see if it was faulty work.

 

Even local repair shops will give you 30 days. They should take care of it for free

 

Local dealer looked at the rear, they said the NJ dealer did not do there work properly, they should of opened the diff and saw that there was a problem. But there shotty work was not the cause of the pinion bearing coming apart. Bearing is shot and the R&P are damaged, LSD is ok. Does anyone know where to get a replacement 3.92 gear, most things I see are 3.90. Would that cause a problem with the 3.92 in the front end?

 

Replacement set here.

http://www.moes-performance.com/mobi...lt.aspx#P37736

 

Thanks, I could not find that on the website when i looked. They don't show up when you are using the full web version, but the mobile version you provided shows them.

 

Glad to help. Let us know how it goes.

 

I got a call from Moe's Performance, they said the gear I ordered from the link above was discontinued by them a few years ago. He had a Motive version of the same gear for less so I went with that. Turns out they never removed it from their mobile version of the website.