Every now and then I get a loud Ping like someone taps on my drive shaft. Only does it in Reverse and not all the time.... Any ideas?
2004 F150 Supercab Fx4 140k Rear limited slip was rebuilt at 70k and New drive shaft at 115k

 

Check your U joints, you might have one siezed up or wore out.

 

I tried wiggling the drive shaft and inspected the u joints so i dont think its wore out but one cap might be seized seeing it only does the noise every so often so it might only do it when that cap or caps get certain pressure... Ill replace them seeing its cheaper then finding out the hard way.

 

Better safe than sorry!