Mine were bad at 7,000 miles .I replaced them with bilsteins. you could tell a lot of difference , the rear end doesn't bounce all over the highway after hitting a bump.
BAD move for RANCHO they will likely lose a lot of business for the deal with ford. I've seen a lot of $40 shocks last a lot longer than 7,000 miles.

http://i579.photobucket.com/albums/s...dead-horse.gif

just saying...

2800 Miles and 3 of 4 were toast.

I ordered my new truck without the FX4 package, in part because after reading all these threads I saw no value in the Rancho "branded" shocks.

Are the standard shocks the same/better/worse than the Ranchos?

so what are the stock non roachero shocks like?
are they any better? do they hold up any better or should I just pony up and buy new ones?

Ordered my RS9000XLs
 

Will post my results after I swap them out....

Don't know why I waited so long to put the Bilstein 5100's on but finally at 25k miles I noticed a pretty 'buck' from the back right of my truck while going over train tracks. Not any more! When I compressed the old Rancho's that I took off, only 1 rear shock rebounded and that was only 2 inches.

I didn't wait for them to go bad. I just changed them out at 750 miles.

That is why I'm thinking if they are toast I should swap them out.
I have 2500 mi. so far. won't it will wear other stuff out premature if it is like there are no shocks under there?:(

replaced at 40k, 3 were junk, replaced w/ bilstein 5100, ride like a truck again

How A Shock Absorber Work
 

The way the suspension works is, the coil spring take the impact and the shock controls the rebound from the spring. Knowing this means that the absorbing stroke of the shock is the when the shock is being extended. Not how long it takes for it to extend, or if it does extend. I would not fail a shock just by doing this. A shock can still be incorrect for your specific application, like towing. If you are experiencing bouncing that slowly reduces or fluid leaking, this can be a shock. Incorrect ride height can also effect ride quality. FX4 package is the Rancho shock add on and their valving is specific for the Ford vehicle they are supplied on and not just a series model, F-150,-250,-350. The Bilstein shock is a great shock as well and they work great on the truck due to their own specific valving.

I currently have 5000 miles on my 2012 f250 diesel and talked with my dealer about my concerns of the shocks and got the reply of " it rides like a f250 should ride no signs of defective shock" went to next level with ford customer service . Now they want a second opinion at another ford dealer.. Am i wasting my time ?? Has anyone got ford to do anything for them???

You are wasting your time trying to get Ford to do anything on the shocks. The factory shocks are just terrible.

For a low buck replacement go with the Bilstien 5100. For High buck, I really like my King shocks, but they are spendy. Icon also makes nice shocks.

Yeah I hear what you are saying , can't believe enough people have not yelled loud enough that Ford will at least listen .... This truck was 62,000 plus sticker and when I spend that kinda money I think I should get quality components . Honestly traded up to this diesel from a KR f150 loved the truck but ford could not tell me how much a spark plug change would be lol because of another one of their faulty parts .

Ok, so after calling Rancho and asking them some questions about the OEM FX4 shocks on the 2011+ trucks these are the answers I was given.

1. Why don't the OEM shocks I removed ever rebound when I compress them.
A. They actually are not designed to be fully compressed until they stop. As long as they are not fully compressed, they should rebound.

Ok, so I checked mine. This is the case for all of them. They would not rebound once they were completely pushed in, but as soon as I pulled them out about 2" they returned to full length (slowly, but they did come back out...probably took 10 second).

2. Are the shocks actually made by Rancho?
A. The intial design and development were all Rancho, the production (To meet Ford's volume needs) were handled by Ford, Motorcraft, to meet Rancho engineered specifications.

3. What Rancho shock are they based on?
A. Initially the RS5000, but they were redesigned to match the handling requirements of Ford.

4. Can you purchase an exact replacement from Rancho?
A. No, only Ford can sell you the OEM shocks.

Interesting. I'm not sure if others have heard the same.