Parts of a Weight Distribution Hitch

All 8 parts on the diagram

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On the tow vehicle 4

Hitch ball It is bolted into the hole in the head's top. The coupler is lowered onto it and latched.
Shank The head bolts to the row of holes on its upright part. Higher or lower to suit the trailer.
Hitch pin and clip It holds the shank in the receiver. The clip keeps the pin from sliding out.
Head (ball mount) The hitch ball sits on top of it. The round end of each spring bar fits into a socket in it.

Bars, chains and brackets 4

Chains One link hooks onto the bracket above. Both chains are set to the same length.
Hookup brackets The chain hooks onto it. It swings up to pull the chain tight. Makers also call it a connection bracket.
Spring bars They lever some trailer weight off the tow vehicle's rear axle. Pulled up by their chains, they move it onto that vehicle's front axle and the trailer's axles.
Sway control It resists the trailer swinging from side to side. A bar slides in a body that grips it. Each end fits onto a small ball and is held by a clip.

How this list was compiled: Part names checked on 2026-09-30; a name is kept only when two independent sources use it. (1) Harbor Freight Tools, 10,000 lb. weight distributing hitch, owner's manual, https://archive.org/details/manualzilla-id-7037744 (square shank, lock pin and spring clip, weight distribution head with sockets, hitch ball, spring bars, chains, connection brackets, sway control kit). (2) CURT Manufacturing, weight distribution hitches, https://www.curtmfg.com/weight-distribution-hitches (shanks, replacement heads, spring bars, hookup brackets, sway control, hitch pins and clips). (3) Husky right-hand sway control instructions, https://archive.org/details/manualzilla-id-6467828 (sway control, slide bar and main body, sway control ball on the weight distributing ball mount, trailer tongue ball, spring clip). (4) A fifth wheel and travel trailer owner's manual, https://archive.org/details/manualzilla-id-5740957 (weight distributing hitch, hitch ball, spring bars and chains, sway control). (5) Wikipedia, Tow hitch, section Weight-distributing hitch, text only (spring bars and chains under tension move part of the hitch weight from the tow vehicle's rear axle to its front axle and the trailer's axles). Licence: own work

The drawing: Drawn for this site on 2026-09-30 from plain geometry; no maker's hitch, nothing traced. Licence: own work

How it works

A weight distribution hitch adds two spring bars to a trailer hitch. Pulled tight by chains, they shift part of the trailer's weight off the tow vehicle's rear axle.

Read the full guide

Find the hitch, then the bars

The side view starts at the tow vehicle: the shank pinned in the receiver, the head bolted to it, and the hitch ball on top. One spring bar reaches back under the trailer's tongue to its chain and bracket. The view from above shows both spring bars along the trailer's frame, and the sway control beside one of them.

The ball is drawn as if you could see through the coupler; the dashed line is the coupler's edge.
This page names the parts. Setting a hitch up is a job for its maker's instructions.

Questions and answers

What are the parts of a weight distribution hitch?

A shank that slides into the receiver, a head bolted to the shank, a hitch ball on the head, two spring bars, a chain on the end of each bar, a hookup bracket on each side of the trailer's frame, and often a sway control.

What do the spring bars do?

They act as levers. With the chains under tension, they shift some of the trailer's hitch weight off the tow vehicle's rear axle onto its front axle and the trailer's axles, so the vehicle and trailer sit more level.

What is the difference between a weight distribution hitch and sway control?

The spring bars spread the trailer's weight across the axles. A sway control is a separate bar that slides in a body gripping it, which resists the trailer swinging from side to side. Many hitches carry both.