Strange Noise

[Blazer24]

99 Silverado Extended Cab, 5.3L

 

???   I have been hearing a ticking sound which appears like it's coming from the rear end.  I originally thought that it was coming from the wheels but after finally being outside the truck and having someone moving it in forward and reverse, I am certain that it not coming from the wheel area.  I'm hoping that someone else has experienced a similar problem and can provide me with a resolution (I'm going to take it in but if it's something simple I'd rather do it myself).  Any help would be appreciated.

 

Thanks

[chevy4x4trucks]

is it your exhaust by any chance?  Sounds odd, does it do it at idle or just while you're in motion?  If it does it all the time I'd think it's exhaust.  Have someone rev the engine a bit in neutral while you listen to the truck.  Otherwise you could have someone ride in the bed for a bit to see if they can hear anything.

 

Could you provide a better description of the noise, constant, intermittent, while in motion, all the time, etc...

[Blazer24]

It's been intermittent when the truck is in motion and under load.  It almost sounds like there is a piece of metal hitting against something while the truck is moving.  I've looked everywhere underneath and found that nothing was loose, pulled all wheels and inspected for any type of debris, also finding nothing (except my rear brakes were getting low    ).  Putting the truck in neutral going down a hill I was unable to hear anything, but the wind noise made it a little difficult to hear.  Let me know if you need any more info.

[Blazer24]

The more I think about it, the more I want to say that the problem is with a U joint.  It's the only thing that makes sense, to me anyway. I would think I would have a vibration of some kind if the problem was in the rear differential, but I don't.  I've had U joints go bad on other trucks but I didn't get this type of noise, but different years and body styles may be the factor there.  Let me know what you think. :thumb:

[Shaners]

Check and make sure that nothing is tapping against your drive shaft.  When I had my Transfer case replaced, they left a cable too close to the front drive shaft, and everytime I engaged 4x4 it would click as it slapped against it while it was spinning.

[2000 GMC]

Hope it's not a bent axel??  

[Blazer24]

It actually was the U joints, replaced and corrected the problem.  The weird thing is, I don't think they were ever good to begin with.  I never liked the way it shifted in the past, I know the trucks had a tendancy to shift hard to begin with so I thought nothing of it.  With the new joints it still shifts hard, yet not like it has since day one.  It is so much smoother in it's transitions between gears now, I no longer dislike the way it shifts.  Or maybe I'm just going crazy.