I have a 06fx4 that makes a loud whinning noise when its cold. The noise goes away when put into 4H and comes back when put in 2H. It has been in the shop under warrenty twice. They changed a valve and a motor which has made the noise louder. Any advice?

 

i have had the same exact problem with my 04 fx4 this winter. it seemed to happen when i was on the highway. when i hit the gas or slowed down it would go away for awhile then come right back. after the truck warmed up it seemed to go away. annoying.....

 

You're putting the front axle under load when in 4H. The noise occursin 2H so the front axle looks to be at fault. Start there.

 

can't be, cause my 4X2 does is as well. When i hit the gas, its gone, or brake, its gone. Only lasts for 45 seconds at the most when its cold. Took it in, they said it was probably a belt, fixed it, never saw a sheet for it. Then 2 weeks later it was back. Bastards....

 

If you have a squelling belt you can put face soap on it while it's running and it will quite