Smart people

I have a 2001 F-250 Long bed with a manual transmission and mannually locking front hubs.

When I turn left or right I feel a thump thump thump in the seat equal to the timing of the rotating wheels. I feel it more when I have a heavy load.

Is this normal?

I don't think the front hubs are locked because I've made sharp turns on asphalt when they are engaged, and think I know what it feels like to lock up. I turn the hubs the right way and back up at least 50 ft, but am never sure if I hear them click out. I'm sure I used to hear them click out but my hearing is getting worse also? Maybe the fronts are still engaged, causing the thumping when turning? Even going 60mph down the freeway I'll feel it in big turns. I'm sure the 4wd gearshift is in the 2wd position, but maybe that means nothing if the hubs are still engaged and causing the tranny to thump?

 

 

Do you have a limited-slip rear diff?

Read around behind the front wheels and spin the u-joints to make SURE the front hubs are unlocked. If the inner spindle bearing (needle bearing) is dry or shot where the axle stub rides, the front axles will still turn even though the hubs are unlocked and it'll feel like the "thump thump" when the hubs are locked.

If it's coming from the rear, that usually means the diff spider gears or clutches are shot. Sometimes, the limited-slip clutches will "chatter" and you might need more limited-slip additive.

 

Had a similar problem on my '05 excursion. The Rear end e-brake pins had rusted through and the wheel studs were slowly eating the brake pad set.

When was the last time you had the rear end cover off? Look at the teeth good, the 10.5 has been said to chip off sone of the ring or pinion teeth when you run larger tires. Not personally my experience on this one.

Keep us posted!