Is there a way to tell which is bad?

I pulled my front driveshaft and my wicked loud subwoofer like hum has gone away. Driveshaft was rebuilt and re-balanced not to long ago, and I assume with how bad it was before the rebuild that it tore up one or both of the bearings, is there any way to test to verify before pulling them?

 

Can you feel excessive play in either of the yokes?

 

If you can't tell where it is coming from when driving around, put it up on jack stands and drive it. Pinion bearing is a lot more common. Get underneath and you should be able to tell where it is coming from. Just be careful.

 

No obvious slop up/down or left right on either yoke.
I only have 2 jack stands, so I guess I'll just be driving around without the front drive shaft for awhile until I figure something out.

 

Pulling front drive shaft and noise went away would suggest transfer case issue to me. Front axle still turning the same if shafts in or not . Have you spun front yoke on tc yet by hand yet ?
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Yea I spun the t-case and couldn't feel anything, and I rocked the front diff yoke and couldn't feel any play there either.

 

Seeing how front shaft out put In 4h and drive see if noise exists. Coulb be piviot ball in front drive shaft also growling .

 

What is a pivot ball? I'll take it out tomorrow and test, I need to be on the highway for the sound to become noticeable.

 

This is between double u-joint at transfer case end ......

 

Drove it on the highway in 4 hi and the sound wasn't there with the driveshaft still out.

Is there a way to diagnose the pivot ball on the driveshaft?

 

Try a buddys front shaft in its place or move drive shaft around in that area see if its strange sounding/feeling.