I bought some new rear shocks, but they seem to be too long. What do you think?

I have a 2005 F150 Lariat, 5.4, Supercrew cab, 4x4, 138 inch wheelbase, 18 inch tires, which I assume are stock

From my research, it seems like the correct part, ASH846, I checked the Ford parts website, then bought the same Motorcraft shocks from Rock Auto.

I don’t know what “Heavy Duty suspension” vs "Premium suspension" means.

Here are 2 pictures: When I put the top bolt in, it’s about 4 inches longer/sticks down 4 inches below the bottom hole.
A Youtube install video shows it only 1 inch longer..

Also, when I lay the new one and old one side-by-side, the new one is 4 inches longer.

What do you think? Is this a problem? Or not?

Seems 4 inches too long

Why is new shock so much longer than old one?


Thank you!

 

Put a bar through the old shock bottom eyelet, hold with your feet, and try extending the old shock further. It may be stuck from age, rust ect. Press both shocks to collapse limit. If they're the same length they should be OK.

 

That is correct, if you purchased OE shocks they have been updated and are longer. This is fine as you have plenty of travel both directions.

 

That strap is just to hold shock some compressed to fit a box. Compress both new and old and compare.

 

And get some new wheels - I have never seen wheels with huge corrosion pitting like that. Pretty soon you'll have to run tubes in your tires.
They should be more compressed to make it easier to install without raising the truck, but that's what you'll have to do in order to install those. Jack up the frame and let the axle hang. You'll then be able to get them into position, then cut the strap and guide the lower end into place. If they are the wrong shocks you run the risk of bottoming them out.

 

I'm bumping this post ^^ as it's the only one I found that mentions the differing height of the rear shocks. Specifically what I've found is that the original shocks were 25" (measured eyelet-to-eyelet at full extension), and the later ones are 27". Does anyone know what the story was behind this change and about when did it occur? 2" is a pretty significant amount. Did the mounts change in some way?

 

I looked up shock lengths for my '07 FX4 after lowering it 2" in back. I removed the blocks, used new shorter U-bolts. I was thinking I'd need FX2 shocks. I used Bilstein's figures. (I lowered the front near 2.25" .... I modded the shock stem itself.)

As it worked out, when I removed a rear shock and compressed it to see if I still had enough travel, I found no need to change them as the shock still had enough travel to absorb the distance from axle top to bump stop.

FX2 or 2x4 rear ...... Collapsed Length: 15.31 in / 389 mm ... Extended Length: 24.94 in / 633.5 mm

FX4 or 4x4 rear ...... Collapsed Length: 16.69 in / 424 mm ... Extended Length: 27.11 in / 688.5 mm

Maybe explains the difference?

 

Ah, so maybe it's as simple as 2WD trucks got ~25" shocks and 4WD got ~27".

The comment above by "ford390gashog" seemed so definitive, I mostly fell for it as a blanket statement. But what you've indicated above makes more sense. Thanks for the input.

 

I haven't compared the lengths since my investigations leading up to my lowering job in 2011, but it was the case then anyway.