Re: 1997 f250 vibration at 55-60
If the noise goes away when the driveshafts are removed..that would make me suspect of the driveshafts themselves or anything downstream they would be attached to... at least thats how i would attack this.
That being said, i would not rule out something internal like the t case- even tho you swapped them out both could have the same issue being 4407ís. If the internal pumps break the main shaft bearing closest to the transmission starves of oil and can literally start disintegrating and short of a slight roaring noise you cant feel any play on the output yokes..you have to tear them down to inspect them.. and it did produce a slight vibration
( this happened to mine and my brothers 4407)
96 F250 CCSB 4x4 E4oD,4.30 gears, 37" tires, 2007 Suspension 160/30, S366 ,Banks IC, Adrenaline, e fuel, AFE, PRECISION TC