Diagnosis suggestions for F150 front end issues.

[Eddo Rogue]

Not sure where to start on on my '08 F150. Front end feels like I am driving over square edges, and its about to explode. I cant visually see anything wrong. I haven't worked on rack and pinion vehicles much, do they have tie rods that go bad? Is it suspension bushings? ball joints? wheel bearings? All the above? At 130k miles, the only things I have changed is shocks and wheel bearings (they come with a rotor). I would rather just throw parts at it than crawl around with a pry bar for an hour and find nothing...

My rotors are warped, but I just live with it until its time for brakes.

 

[Uncle Gump]

Is it 2WD or FWD?

Rack and pinion steering has both inner and outer tie rods.

Maybe a better description of the symptoms too.

 

[Eddo Rogue]

Sorry yes 2wd. It kinda feels like a flat tire. I'm running Falken LT's down to 55psi to reduce the bump steer. At speed on the freeway it's as if I'm driving over a bunch of little bumps...

 

[dvdswan]

Are the tires load range E? Do the tires have cups or flat spots? Does it change if you swap the front and rear tires?

 

[Eddo Rogue]

I think so yea...they call for 80psi. I wanted super beefy tires to handle capacity loads easily and not pop rubbing rain gutters. Good suggestions, I should probably start with a tire rotation...maybe check for missing wheel weights....

 

[4x4prepper]

> At speed on the freeway it's as if I'm driving over a bunch of little bumps...

Many times when I have seen that happen we ended up replacing the shocks. Good enough to about 45 MPH and then vibration bad enough to think you have death wobble. Even though the shocks had passed the bounce test and had resistance (gas shocks) the shocks were still bad.

 

[Eddo Rogue]

> At speed on the freeway it's as if I'm driving over a bunch of little bumps...

Many times when I have seen that happen we ended up replacing the shocks. Good enough to about 45 MPH and then vibration bad enough to think you have death wobble. Even though the shocks had passed the bounce test and had resistance (gas shocks) the shocks were still bad.

You might be right...that is pretty much exactly what it does. I replaced shocks recently but Rancho is hit and miss...maybe the are blown already.

 

[Curious Hound]

Sounds like a lot if pressure for an unloaded truck. Just because the tires have a high max air pressure, doesn't mean you have to run that much all the time. Someone posted a calculation recently that you use to figure out the right pressure for the load that is actually on the tire. An unloaded F150 isn't terribly heavy. Then just raise the pressure when you put heavy loads on the truck. How does it ride at 35psi?

 

[85_Ranger4x4]

Sounds like a lot if pressure for an unloaded truck. Just because the tires have a high max air pressure, doesn't mean you have to run that much all the time. Someone posted a calculation recently that you use to figure out the right pressure for the load that is actually on the tire. An unloaded F150 isn't terribly heavy. Then just raise the pressure when you put heavy loads on the truck. How does it ride at 35psi?

+1

I run my F-150 at 35PSI and it rides great. 40+ unladen it rides like a lumberwagon.

 

[Eddo Rogue]

Sounds like a lot if pressure for an unloaded truck. Just because the tires have a high max air pressure, doesn't mean you have to run that much all the time. Someone posted a calculation recently that you use to figure out the right pressure for the load that is actually on the tire. An unloaded F150 isn't terribly heavy. Then just raise the pressure when you put heavy loads on the truck. How does it ride at 35psi?

Yes way too rough at 80psi. I run em at 55 psi. I'll try 35psi. Gonna rotate em this weekend on day off.

 

[Eddo Rogue]

Hey guys, thought I'd update this thread.

Noticed weird wear on my front tires, which indicated worn shocks/ out of balance tires.

Noticed weights missing off the wheels. took em in, all 4 were out of balance. One was really bad.

Balanced and rotated the tires, and it helped a lot!

I ordered some bilsteins and brakes. should fix it the rest of the way.