Intermittent Noise or Vibration at HWY Speeds after driving for 1hr +

[costalcat]

Hello all,


I have searched on this and not really found anything that applies.

I have a 2003, 190,000 miles. Recent work done, new tires and new steering rack. Outside of that the only work done other than PM has been a DT Exhaust, cat back, and Airlift 1000 bags. She drives very smooth, straight as an arrow no shimmies at any speed, just solid good ride all the way around. I do a lot of road trips in her and the last couple of trips I get this weird noise after about an hour or so of driving. It is in the rear, as far as I can tell, around 63 MPH. It is gone as soon as I let up off the gas or accelerate past 65 and will sometimes come back. It is not all the time, and it sounds like a wind vibration or exhaust noise.

I have crawled all over the vehicle, had it on the lift at my buddy's shop this week, and I can't find anything that would point to this noise.

Like I said it only happens after some drive time but is easy to make go away. If it starts, I can make it come back by slowing down or speeding up to @ 63. Completely confused here... Could it be CATS breaking up and only happening after it warms up? But why would it not be all the time?

Any thoughts would be appreciated

 

[STIGPIG]

I'd definitely try greasing both driveshafts and if you have the time, remove the rear shaft (be sure to mark it for realignment) and clean the splines of the slip yoke.

I am currently battling a vibration but it's coming from my aftermarket CV shafts.

 

[K5Guy]

Might be a Wheel bearing. Or a really small crack in the driveshaft. That happened to my moms vehicle there was a noise that only started at a certain speed and not every time. We removed the shaft and there was a small crack on the yoke.

 

[costalcat]

Thanks, @K5Guy and @STIGPIG

I was able to get some lift time last night at my buddy's shop. I did a complete inspection of the underneath, much easier to do standing up than laying on your back! Looks amazing under there for a 190,000 mile vehicle.. We both could see nothing of concern from a visual perspective. What I did was grease and lube everything I could drivetrain wise. Took it for a test drive with him as I wanted another opinion and of course I could not get it to make the noise. To both of your points if this doesn't help then I am going to drop the drive shaft and look there.

Thanks again.....

 

[aging fleet]

Possible vibration caused by the removal of that weight that hangs from the frame on the driver's side? Long shot, but would be easy to test.

 

[costalcat]

Possible vibration caused by the removal of that weight that hangs from the frame on the driver's side? Long shot, but would be easy to test.

I did not think to check that when I had it up on the lift. Easy enough to check though and worth a look. On a work trip so when I'm back on Friday I have a 2 hr drive and will check prior... Hoping the lube job did it but I will check this as well.

Thank you!

 

[costalcat]

Well, it was certainly much better but I did get it to occur again. I think next to going to drop the drive shaft . Any maintenance suggestions while I tackle that? I may drop the exhaust as well my gut says there could be a leak I just can't see somewhere...