I just got a 99.5 F350 Supercab with PSD. The truck has 55,000 km (35,000 mi) and there is a weird sound coming from the front. I think it is around the front right wheel. It seems to be kind of a repeatitive "whoomp whoomp" that gets louder at like 30 mph and then fades at 40 mph. It gets louder again around 50-65 mph. The truck had a safety and alignment before I got it and they only found a bad ball joint on the front left. New brakes all around. The truck doesn't seem to have any bounce, so I don't think it is a bad tire. Any ideas what it could be??

The front right locking hub turns but is much harder than the front left. I've checked the axle to see if it is turning with the wheel but seems to be unlocked.

Is there a way to lubricate this hub? Do you think the two are related in any way?

 

Very interesting, I have the exact same problem.

 

Could it be the bearing? It doesn't sound like the bearing but who knows what a "1 piece sealed bearing" sounds like when they go bad. i don't. Just a thought. Sounds like you've looked in all the usual places.

 

Thanks for your thoughts... I'm hoping it's not the bearing as I understand they are expensive. If I lift the truck on jack stands how do I check the bearing? The tire should rock in and out on centre right?

How heavy duty do jack stands need to be to support the front end of this beast?

I'd like to get it up and be able to look around, maybe take the wheel off and see what's going on.

Any other input appreciated.

 

Yeah when you get it up on jackstands the tire should not wobble on it's center with you pushing and pulling on the top. Don't do side to side because of the steering gear. It may have some play and mislead you.