So my previous post talked about this chirping/squeeky sound from the engine bay area. As suggested by some replies to the post, the serpentine belt was replaced as were the tensioner and a few pulleys. Also, the front drive shaft was greased up nicely. It should be noted that the belt was only slightly worn, as were the pulleys. The front prop took very little grease. The chirping/squeaky noise is still there and as mentioned in the previous post, the sound only occurs when in drive mode with forward motion and is proportional to the acceleration - almost a one to one ratio; meaning, gas pedal down, noise is faster. As the Landy slows down, chirping noise slows as well and stops when the landy stops. No noise in P or N mode. Finally, I replaced the front prop shaft from the OEM in June of last year. The front prop shaft was purchased from BPU. This '03 disco is a soccor dad daily use SUV. So, no off-roading stuff. Finally, chirping noise started when I did not use the disco for over a week.


Given the above remedies have not worked, should I assume my front prop shaft is defective and, is this even possible? Center ball failing? I'll try and jack up the landy on all fours and place the tranny in D to see if I can actually better pin point this noise. In the meantime, if I need another front prop shaft, any other vendors to consider? Do they even make a sealed bearing front prop shaft - similar to oem but without the worries of the front prop failing and knocking out the underbelly of the tranny?


Thanks

 

I'm not aware of any issues with the prop shaft from BPU.

 

The failure of the sealed U Joint OEM shaft is related to it being located inches away from the Cats and having a steady stream of AC condensation dripping on it. There could be other things dripping there too but this is the reason you need a greaseable shaft... hostile environment, not bad design.

 

yes. I would grease the drive shaft if you can'
If you can't grease it it will fail probably and if the front drive shaft then it may ruin the
transmission.

I would replace the Drive Shaft with greasable.

 

You could have a front hub in the early stages of failure...

 

Good call on the front hub. Replaced the right front a year ago to date. hmmmm. maybe early failure on the right front hub again?; maybe the left hub giving way? Although the sound seems to be coming from the front passenger side again....


Is there a way to trouble shoot which front hub might be giving way besides the obvious "wobble" when driving?

 

Lift the Disco and grab the wheel at 12 and 6 o'clock and push and pull in opposite directions and feel for any play. Doing the same thing at 3 and 9 o'clock would be how you would check for tie rod ends... If it moved when you push and pull at 3 and 9, but not at 12 and 6, then you have an issue with your rod ends. If it moves at 12 and 6 and also at 3 and 9, you have a hub issue and possibly a rod end issue as well.

If it moves at 12 and 6 and 3 and 9, you can further diagnose the rod ends by prying on the top of them and pushing down to see if there is play in the rod end. It is important to check the rod ends if the hub is bad so that you can replace it all at once.

Rod ends on these involve replacing the drag link and the track rod as one end of each of them has a non removable joint. Or, you can look into aftermarket options that exist that allow replacement of the rod ends on both ends of the track rod and drag link.

The rod ends would not cause the chirping, but that could be coming from a failing hub.

Good luck diagnosing it...

 

To Triple Threat:


It just occurred to me that if one of the hubs was in early failure mode, why doesn't the chirping/squeaky noise continue when I place the tranny in neutral mode and coast? Note I can coast at any speed on the chirping/squeaky noise does not go away. The noise seems to only happen when in the tranny is in drive mode, and at any speed. I'd shoot a vid, but there is so much artifact noise that it would be hard to hear this chirping sound.


It is interesting to note that there is a correlation when the throttle is "revved" up when driving and the chirping noise erupts. Again, only when in D mode and not in N or P mode.

 

That's interesting... Could still be a hub, as when under power, there are different stresses being placed on the hub than when coasting. The forces of acceleration cause the forces acting on the hub to change direction.

Might not be a hub, but the characteristics of your symptoms wouldn't completely eliminate the possibility.