Hi guys,
I hope you can help me. I am new to this site and do like my truck. I have a 08 F150 super crew with 267,000 kms on it. I have developed a whirring noise under load that stops when I take my foot off of the gas. it gets signifanctly loader the faster you go. When I break sometimes sounds like brakes without the pad type of grinding. I have just replaced my brakes front and rear so I know it is not that. It sounds like it is coming from the rear end. it was due for a change of lubricant so I took off the cover and everything looks great. I am also getting that bump that is mentioned on another post today where every now and then in traffic after i slow down and then speed up I get a clunk. I am not having any issues with heat, or vibration, gas mileage. I just drove to Seattle from Vancouver and back over the weekend and got 700 km on 3/4 tank of gas.
I am interested in your thoughts.
Brian

 

Take a look at your ujoints.

 

If it changes when you take your foot off the gas, I would be concerned about the rear end.

 

My joints are tight and I had the cover off the rear dif and inspected it myself and a HD mechanic and it looks great.

 

Taking the diff cover off doesn't show all. Could be your pinion bearing. When those go they whine when driving and get louder (almost a grind) when off the gas.

 

How do you check to see if the pinion bearing is going? I have put on probably 5000 km and doesn't get worse??.

 

You have to pull the drive shaft off the diff.

 

Haha love that guys videos! Beers!

 

These trucks are infamous for rear end howl. I've had dozens of them apart for the same howling complaint. Some had bad bearings but most had nothing wrong. I believe ford may have redesigned the cut on the ring and pinion gears but didn't help much. Give the pinion a wiggle to check for play, and rotate it to feel for roughness. Make sure the breather is not blocked and keep an eye on the pinion seal for oil leaks. As for the grinding I would recheck your brake job. I know you get a lot of rain out there, if the truck sits for a few days it may build up some rust on the rotors. That can cause a grinding noise that will fade with some use. If you find nothing with the howl, I wouldn't worry about it unless it starts getting worse

 

Theses are the words I used to live by in high school, driving cheap cars hoping they keep on going.

But now that time has past and when you own vehicles that cost a fair amount of money you definitely want them running, sounding, and looking good all the time. Whats the point of owning something nice if your not gonna take the time and keep everything sorted out.