# Triangulated 4-link (solid axle)

> What is a 4-link suspension and why do crawlers use it?

- Category: Car design › Suspension geometry
- Kind: Standard part
- Basis: Design rules and figures from the cited sources; example geometry by Xem Studio
- Page: https://xemstudio.com/objects/four-link-solid-axle/ · JSON: https://xemstudio.com/api/geometry?object=four-link-solid-axle · Plain text: https://xemstudio.com/objects/four-link-solid-axle/sheet.txt
- License: dimension sheet CC BY 4.0 (Xem Studio); files CC BY 4.0 or their publisher's license
- Use in every chat: add https://xemstudio.com/mcp as a connector (https://xemstudio.com/use-with-ai/)

**Exact dimensions.** True size, with no printing tolerance added.

## Notes

- A triangulated 4-link locates a solid axle with two lower links and two angled upper links; the triangulation locates it sideways so no panhard bar is needed (Axial).
- Axial says it moves the axle in a more linear path with less sway, steer and torque twist than a 3-link. Builder rules of thumb on NC4x4: at least 6 in of vertical link separation at the axle and 40 deg or more of triangulation for lateral control.

## Sizes

| parameter | value or range | source |
|---|---|---|
| Vertical link separation (full size) | 6 in or more | NC4x4 forum (rule of thumb) |
| Triangulation | 40 deg or more | NC4x4 forum (rule of thumb) |
| Upper vs lower links | uppers shorter so anti-squat falls with droop | NC4x4 forum |

## Where the files are

- Axial: [Suspension Link Types Explained](https://www.axialadventure.com/axi-blog-archive-suspension-link-types-explained.html) — web — Publisher's page; dimensions are facts
- NC4x4 forum: [General 4 Link Suspension Design Information](https://nc4x4.com/forum/threads/general-4-link-suspension-design-information.72892/) — web — Publisher's page; dimensions are facts

## Questions

**Why triangulate?**

To give lateral location without a panhard bar (Axial; NC4x4).

## Fits with

- [Camber angle](https://xemstudio.com/objects/camber/)
- [Caster angle](https://xemstudio.com/objects/caster/)
- [Front kick-up (RC)](https://xemstudio.com/objects/kick-up/)
- [Front toe (toe-in / toe-out)](https://xemstudio.com/objects/toe-front/)
- [Rear toe-in](https://xemstudio.com/objects/toe-rear/)
- [Ackermann steering geometry](https://xemstudio.com/objects/ackermann/)