Roar from the read end

[geneange]

I have a load roar or hum that sounds like it is coming from the rear end (my wife calls it a jet engine). The sound increases as the speed increases. I have about 150K on the 2001 Silverado. To my knowledge the transmission has never been serviced. The level in the rear differential is good (slightly high). There is no difference in the performance of the vehicle and the sound has been there for a couple of thousand miles.

Anyone else have a similar experience or any ideas?

Thanks

[jethro_3]

Are you familiar with the frase, "And Boom Goes The Dynamite!!!"

Get to a tranny shop and let them do one of their "Free Inspection" drives. Get the estimate and then go to another shop and do the same "Free Inspection."

Worst case they disagree on what is wrong. Best case you will know what parts you willl be looking for and you will also know if the parts are above your knowledge.

Good Luck.....

[Ape0r]

Could be bearings going bad in the rear end. On a solid axle there are five: pinion, either side of pumpkin, and at the end of the axle shafts.

[tykrz]

1) undo drive shaft and if 2 piece take apart from behind steady brg and then check the steady brg and make sure it spins smooth...if rough-replace.

2) Spin the yoke on the differential and feel for roughness...if rough you need to replace pinion brgs. Also remove tires and brake drums and spin the axles and check for roughness of the axle bearing.

3) if all ok, it's in all likelyhood the gear set worn out and howling.

hope that helps somewhat.

[GMMerlin]

Originally Posted by Ape0r

Could be bearings going bad in the rear end. On a solid axle there are five: pinion, either side of pumpkin, and at the end of the axle shafts.

Actually there are 6
2 on the pinion, 2 on the case and one on each axle.

You can drive the vehicle for 5-10 miles and then when you stop, touch each area of the diff with your hand (be extremely carefull, it could get really hot, use a glove first, if you feel the heat in one area and not on the others, then that is where the bad bearing is)
That is an old school trick to finding a bad diff bearing...you could use a laser thermometer to do the same thing...a lot safer too.