is the sound coming from the motor or the tranny?

 

honestly i cant tell. only thing i can tell is i THINK its coming from the right side of the truck. beyond that i couldnt tell ya, besides that if it does it when im sitting in a drive thru, i kill the engine so it wont give me a headache. im very sensitive to high pitched noises... the hartmonic resonance gives me a headache, and if someone blows a dog whistle near me, it makes my head hurt really bad

 

fixed the phasing on the shaft...vibration still exist. Anyone got any other ideas???

 

As noted earlier, try turning one end of the shaft 180 degrees. Sometimes it phases better in one orientation vs. the other (since it can go together 2 ways). If that doesn't help, a few choices:

1. Remove rear shaft and drive in FWD, if the vibes go away, it's something in the rear shaft.

2. Take shaft back to shop that messed it up and have them fix it.

3. Take the shaft to a driveline shop and have it checked for runout and balance.

 

Removed the shaft and drove in fWD vibes get worse the mechanic said. I stated this above I think(post #8).

 

Assuming you trust the mechanic, and indeed the vibes are worse, then it may be nothing to do with the rear shaft (afterall the rear shaft is not there with that test). Might try it yourself to see if it is the SAME vibration or something else. Could be the front shaft is is messed up or you might have a bent rear axle shaft or something else going on (broken belt in a tire, bent wheel, etc.). Check the rear wheels for runout.

 

Well the tires only have about 14k on them...I rotate them reguarly and look for broken belts. I dont see any, and the tread seems to be wearing fine. The wheels are brand new, put them on about month ago. Could be a bent rear axle shaft I guess. Like i said the vibrations are in the seat and u hear the low humming noise from the rear. I dont normally ride on the highway with my hubs locked...bout once a month I do for about 10 miles to keep the 4wd working properly. This problem has become very annoying...especially on my wallet.

 

Did You drive it with the rear shaft removed?

I hate to be like this, but I don't know many techs that would do this. Especially if it would show there was something wrong with the work they did.

 

Well i trust this guy, he always helps me out. He could be lying to me but...why would he go through so much trouble to take out the shaft if he wont gone tell the truth. I saw him take the shaft out and drive it.

 

Aite...I drove it today and I had a load in the bed of the truck. No vibrations while the load was up there...but once the load is off...the vibrations come back. Any ideas guys?

 

Load will change the ride height and that can affect the angles on the driveshaft, more so with a CV shaft but also with a u-joint shaft due to the shackle angle change.