Hydraulic Top Out, or HTO, solves a specific problem: when a shock is nearly fully extended, a harsh top-out can jolt the truck exactly at the moment the suspension has the least travel left to absorb it. HTO forces shock oil through a secondary shim stack near full extension, slowing the shaft down before it reaches the end of its travel instead of stopping abruptly. This matters most after adding heavier tires or lifting beyond factory spec, both of which push a shock closer to full extension more often.
This is the rear shock in Fox's 2.5 Performance Series HTO lineup for Super Duty, built for stock height up to a 1.5" lift. The 2.5" body is Type II anodized aluminum, larger than Fox's 2.0 line for more oil capacity, and a 5/8" hard chrome shaft and internal floating piston round out the core design.
Sold individually, order two for the rear axle. This is a straightforward bolt-on with no reservoir to mount, top and bottom mounting bolts is the whole job.
Fox sells this same HTO shock in several lengths for different lift heights on this platform, confirm your actual lift height, not just "Super Duty," before ordering, since the wrong length will either bind or top out.
