I had a question my Bronco rides pretty good we just use it to drive back roads when I get her over 55 she kind of shakes and sounds like my tires are running over something bump bump what could that be thanks
If the condition is engine-speed sensitive, the condition is not related to tires.
Retain all normal loads in the vehicle. Inflate all tires to the pressure specified on the Safety Compliance Certification Label (usually located on the inside driver's door pillar).
Check both front tires and make sure they are the same size, ply rating, and load range.
Inflate all tires to specified pressure (cold). Check both front tires for the same size, ply rating and load range.
Check for excessive front wheel bearing end play. Refer to Wheel Bearings, Front, in the Adjustments portion of this section. Adjust and/or replace the front wheel bearings. Refer to Section 04-01A or Section 04-01B.
Check for worn or damaged ball joints. Replace the ball joints or spindle pins (kingpins). Refer to Section 04-01A (4x2) and Section 05-03A or Section 05-03B.Check for bent steering linkage or excessively worn joints. Refer to Section 11-03.
Check the steering gear mounting bolts and tighten to the specified torque. Refer to Section 11-02B or Section 11-02D.
Inspect the radius arm if bent or damaged. Inspect the bushings at the radius arm-to-frame attachment for wear and looseness. Repair or replace parts as required. Refer to Section 04-01A or Section 04-01B.
Check other suspension components for damage.
Check for aftermarket changes to steering, suspension, wheel and tire components (i.e., competition, heavy-duty, etc.). Specifications in this manual do not apply to vehicles with aftermarket changes.
Sounds like a bad tire or balance issue, maybe flat spotted. Go get them balanced, tire shop should notice if there is something wrong with them. Typically a bad tire takes a lot more weight than the others.
Otherwise grab the driveshaft and make sure it is solid.