'02 F350 with 6 speed, manual xfer case, and manual lockouts. With hubs locked and xfer case in 2 hi, I hear a rythmic thumping sound when making a sharp turn on pavement. Same sound as when turning left or right. Sounds like it's coming from the front left hub. Replaced the left hub/bearing assembly and axle u-joints look fine.

Jacked up the front end so that both tires were off the ground. Turned tires all the way to the left - all seemed ok. Turned tires all the way to the right, and the right tire was now touching the ground and the left tire had lifted approximately 1 in. The front end was probably not level when I did this and the measurements were crude, but I don't understand why one side would drop and the other would rise.

Truck drives fine otherwise with no shimmys or unusual vibrations.

Any thoughts?

 

It is normal to experience some binding, thumping or even a little hopping when you are in 4 wheel drive and have the steering wheel turned to full left or right.

 

The problem is occuring in 2wd, not 4wd. That is, the noise I'm hearing is with the hubs locked and the transfer case in 2wd.

The truck was also making a rumbling sound when in 4wd, which turned out to be a bad cardan joint in the front driveshaft. I had the front driveshaft rebuilt, but I'm still hearing this rythmic thumping sound, although it now sounds as if it's coming from the front driveshaft area.

I'm planning on removing the front driveshaft and driving the truck. If the noise is still present, it must be in the front hub assembly somewhere. If the noise isn't present, it must be in the recently rebuilt front driveshaft, or transfer case. Puzzling problem???

 

im thinking you might have a bad front axle u-joint...

 

They seem to be ok when I turn them by hand. Don't exhbit any noise or binding, but you may be right.

This is my first 4x4 with this long of a wheelbase. In 4x4, it really bucks and hops when making a turn on dirt. It almost seems as if some component is binding up. My other 4x4s didn't seem to exhibit anywhere near this much bucking and hoping. Is this normal for a long wheelbase truck like this?

 

My 2003 w/Esofs will thump in a full lock turn when locked in and in 2 wheel drive.