[cosworthcrazy]

I have a 1997 F150 4x4 XLT extend cab w.4.6l triton. The truck has 225,000 miles on it. I have developed a noise and vibrationin the rear of the truck. It sounds like someone wrapped zip ties around the drive shaft and they flap against the under body, it is also accompanied by a vibration. It starts anywhere from 25 - 30 mph and gets worse with more speed. It also goes away when when I'm applying the gas. It doesn't seem to matter if the truck is in gear or not. I need a starting point to diagnose it, I'm sure its a common problem with higher mileage vehicle's

 

[Mr Mac]

Have you at all checked your U-joints on the drive shaft? Warn U-joints can cause vibrations in the driveshaft.

 

[cosworthcrazy]

I will, I am just looking for starting points, how about the accompanying noise? It started before the vibration.

 

[Mr Mac]

Another good place to start would be with the wheels and brakes. Make sure everything is tight and nothing is excessively worn. While there, take a look at the exhaust sytem (pipes, hangers and catalytic converter). You can also check your bed bolts while underneath the truck.

 

[cosworthcrazy]

Thank you for your advice, since the noise and vibration are related, I'm going to start with the U-joints and then looks at the hubs, bearings etc. I noticed that when I got the truck a year ago it was dry underneath. Now the rear differential has some wetness on the out side, could there be anything in there I need to look at?

 

[Mr Mac]

By all means, check your gear oil level. It should be right at the upper hole.