Low Frequency Growl, Coasting :-(

[TMoran]

My 2001 2500 generally pulls my 12,000# 30' 5er, but not for this event.

Tires, tran temp, and fluid OK. Condition of universals and limited slip unknown.



1. Coasting in 4th, overdrive in 47RE, there is a low frequency growl



2. Acceleration the growl stops



3. Shifting to N, coasting, the growl stops



4. Returning to D, coasting, the growl returns slighly louder.



Where shound I start. Getting worried! PapaTom

 

[JLandry]

How many miles on the truck?

I'd start by replacing all the u-joints and the hager bearing because that's a relatively inexpensive thing to do... and it probably should be done anyway after 100,000 miles as a routine maintenance item. OEM Spicer u-joints typically cost about $30 each, and the hanger bearing can be purchased for around $65 from rockauto.com.

If the sound is still there after replacing the u-joints, have the differential looked at by a qualified shop.

Good luck,

John L.

U-joints

 

[TMoran]

Thank you John L. That is good advice and I will follow it. The best approach is first less expensive things for me. The truck has 130,000 miles and the back axle is near gross as the Yellowstone is nose heavy. PapaTom

 

[BSeyler]

I'd also pull the diff. cover and see what comes out. Then, each axle. Typically, a roller bearing that has a lost or damaged roller will be quiet under load (throttling) and make noise when unloaded (coasting).

Bud

 

[TMoran]

Thank you BSeyler. I have not done the rear end and of course now I feel guilty. PapaTom