So, if any of you have been following some of my posts recently on wheel bearings and center support bearings then you will have an idea of what I have been dealing with lately.

I just recently changed out the center support bearing which was giving me a good vibration and noise at 30mph and up. That problem solved! New bearing and all that went away. Before that, when I was trouble shooting the noise I found bad needle bearings in the front. Those have been changed out.

Took it for a spin on the highway yesterday got to 75mph and I had quite the resonating sound coming into the cab. Don't know where it's coming from. But it sounds like when you have your hubs locked and you cruise down the road and it's always a little louder when they are locked. But the sound is 5 times louder than that. Never had this issue before.

I double checked to make sure the hubs were not locked. Tires were just rotated. Alignment was just done about 6 months ago. Tire pressure is all good. Lugs are all tight to torque specs. When I had the drive shaft off for the center support bearing I lubed the spline and greased by u-joints. I can't find anything that is touching or rubbing that would cause a sound like this. Here is what else I have changed:
Front Sway Bar End Links
Upper Ball Joints
Lower Ball Joints
Outter Axle Dust Seals
Replaced Hub Vacuum Lines
Front Sway Bar Bushings
Front Wheel Bearing Assemblies
Front Brake Rotors
Front Brake Rotors

I have not changed the front axle u-joints. Not sure if that is a culprit or not. Both the front diff and rear diff fluid has been changed and are full. T case has been flushed and re-filled. Can you see the $$$$$$ signs here? I'm really frustrated with the constant maintenance that is required. I'm sure the age of the truck has something to do with it, but damn! I haven't even hit 200,000 miles on it. I know I'm not the only one who is feeling this pain, not to mention the pain I get from my wife when I tell her there is something else wrong with the truck.

So, as usual I come here for help and advice from those who have possibly been through this before. I would just like my truck to drive normal again.

 

Had the same sound Don, when after dropping the driveline. Retraced my steps and only thing I didn't do was rereading the spiked shaft. I didn't have the blue cheese but at that point, any grease was better than nothing... The harmonic noise was at a mute...

 

What fluid did you put in the transfer case?

 

Did You get Your drive line clocked on the splines correctly.

 

Well I lubed that shaft when I had the drive shaft off. I just can't figure out where this sound is coming from.

 

Mobile 1 Synthetic ATF.

 

I believe I did. I marked everything before I took it off and then re-installed it all the same way. Everything lined up. Hopefully it's in right. How would I know if it wasn't?

 

Ford is now recommending "Motorcraft Transfer Case Fluid" only due to catastrophic failures.

http://parts.autonationfordwhitebear...m/oe-ford/xl12

 

Hmmm, good information. Thanks for sharing that.

 

the yokes should be 90 degrees clocked

 

Ok, I'm the type of guy that needs a picture or diagram. I'll just say it, coloring books. This is probably really simple but I'm not following. So if I can get this spelled out for us not so sharp guys I would appreciate it.

 

So, before I start, I need someone to look at my previous post. I took the truck out on the highway again yesterday and the same noise/vibration is still there. It's so bad that my side mirrors vibrate so much that you can't see clearly out of them.

Still can't pinpoint where it's coming from. Not sure if it's the driveshaft or not. I'm going to be changing the fluid in the T case this weekend. Maybe it's that, I really don't know. I'm speculating again, like just about every time. I really need some thinker cap help on this one guys. I would hate to have to take this in to someone to find out what it is.

 

Here are some of the causes of vibration I have personally experienced on two of my vehicles:

• Rust growing behind the rotors - this can cause spreading in there, making the wheels wobble a little.
• Bent rims.
• Driveline not balanced.
• Bent driveline.
• Damaged U-joints.
• Warped rotors from siezed caliper slide pins.
• Loose front end components.
• Under-inflated front tires.
• Tire imbalance.
• Poor "automotive" front end alignment on a "truck".
• Uneven tire wear (caused by many of the above, as well as bad shocks/springs)

It helps to know the frequency of the vibration. Half-RPM is usually combustion related, RPM can be engine/torque converter related, influenced by speed only (coasting at different speeds in neutral) can be driveline, axles, wheels, tires, brakes, etc....

Noise, Vibration, and Harshness (NVH). There are Android apps (maybe iOS as well) that can be downloaded [LINK][LINK], this would allow an Android device to record the sounds your truck makes. If you were to try this, I would suggest an external microphone attached to something hard on the truck, away from the firewall (no need to get engine noise).

 

Thanks for the input Rich. I'm going to go through that list and see what I come up with. I don't believe the driveline is bent. I'm not sure if it is out of balance. That could be. Would I have to do what you mentioned before and put the rear on jack stands and look to see? Or could I bring the driveline in to someone and have them test it? Just trying to figure this all out. I just need this vibration to go away and the truck will be back to normal again. I'm noticing this vibration/sound at speeds above 65mph. It's when you get into the 70 to 75 mph range that it's humming pretty good. And it seems like when you left off the pedal from 75mph it gets even louder until it slows down to 65 or less. It's really weird.

 

The place to start is with the last thing you did, or the last part you changed out, before the noise appeared. If I understand you correctly, you just had the rear driveline out to replace the carrier bearing. I would start there. Have the balance checked, and make sure the splines are aligned the same as when it came out. Also, could the carrier bearing be defective, or the assembly mis-aligned ? No reflection on your mechanical abilities, just seeking answers.
Since the front driveline doesn't move in 2wd, I don't think this is a factor. Also, IMHO, if the transfer case has the right grade of clean oil, I don't think the brand will cause the noise you are describing.
The next place I would look is your transfer case, as in the internals. How old is the chain ? They can wear and stretch over time, and this, along with worn gears or a worn detent mechanism, may cause the noise and vibration you feel. After all, the output shaft goes into it, and the rear driveline comes out of it, so it turns with the transmission. I just had mine overhauled not too long ago. I have also read about several owners finding the T-case mounting bolts backing out, or even falling out. Might want to check this first !
Anyway, just some thoughts. Hope this helps you out. Good luck brother, keep at it !