If you're building a rock crawler, rock bouncer, Jeep, Ultra4 car, mud truck, or custom off-road vehicle, suspension links are one of the most important components underneath your rig. They control axle location, suspension movement, and take tremendous abuse every time the tires hit a rock, ledge, or obstacle.
One of the most common questions we hear at Wide Open Design is:
"What size aluminum suspension link do I actually need?"
The answer depends on several factors including vehicle weight, link length, available clearance, and the rod ends or joints you're using. In this video, Adam walks through the process of selecting the proper 7075 aluminum suspension link diameter and thread size for your application.
Watch the Full Video
Why We Use 7075 Aluminum Suspension Links
At Wide Open Design, we build our suspension links from 7075 aluminum because it offers an excellent combination of strength, durability, and weight savings. Unlike steel links that often stay bent after a hard impact, 7075 aluminum has memory characteristics that allow it to flex and return closer to its original shape. This makes it a popular choice for:
- Rock Crawlers
- Rock Bouncers
- Ultra4 Cars
- Jeep Builds
- Trail Rigs
- Mud Trucks
- Mega Trucks
- Custom Tube Chassis Vehicles
However, simply choosing aluminum isn't enough. The diameter and wall thickness of the link must be matched to the vehicle and intended use.
Bigger Is Usually Better
When selecting a link diameter, Adam's advice is simple:
If you're on the fence, go to the next size up.
The weight difference between a larger diameter link and a smaller diameter link is often minimal, but the increase in strength can be significant. This becomes especially important when looking at:
- Longer suspension links
- Heavier vehicles
- Racing applications
- High-horsepower builds
- Aggressive rock crawling
The greatest strength gains occur in the threaded area of the link as well as the center section where bending loads are highest.
How to Determine Thread Size
Many customers are simply replacing an existing suspension link while keeping their current rod ends or joints. The easiest solution is to identify the manufacturer and part number of the joint already installed on the vehicle. If that information isn't available, you'll need a few simple tools.
Tools Needed
- Digital Calipers
- Thread Pitch Gauge
- Existing Rod End or Joint
Using calipers, measure the outside diameter of the threads.
Then use a thread pitch gauge to determine the thread pitch.
For example:
- 1.25" diameter
- 12 threads per inch
- Would be identified as:
1-1/4"-12 Thread
You'll also need to determine whether the joint uses:
- Right-Hand Threads
- Left-Hand Threads
This information allows us to build links that match your existing suspension components.
Measuring Suspension Link Length
When ordering replacement links, the most important measurement is:
Jam Nut to Jam Nut
Measure from the outside face of one jam nut to the outside face of the opposite jam nut. This provides the finished link length needed to match your current suspension setup. For custom applications, be sure to verify:
- Suspension geometry
- Available chassis clearance
- Tire clearance
- Full suspension travel
Need a Custom Thread Size?
Not every suspension joint uses a common thread pattern. Some manufacturers use unique metric thread combinations that may not appear in standard ordering menus.
For example:
- M30 x 1.5
- Specialty steering joints
- Custom tie rod ends
- Proprietary suspension joints
In these situations, we can often machine custom thread patterns. Typically, we simply ask customers to send us the joints so we can verify fitment and ensure everything threads together correctly before shipment.
Use the Link Sizing Chart
To make the process easier, we've created a suspension link sizing chart that helps determine the appropriate:
- Link Diameter
- Material Size
- Vehicle Weight Range
- Recommended Link Length
The chart is available directly on our website and is designed to help builders select the proper link for their specific application.
Final Thoughts
Choosing the correct suspension link is about more than simply ordering a piece of aluminum tube. The right diameter, thread size, and length all play an important role in suspension strength and reliability.
If you're unsure what your vehicle needs, don't guess.
Measure your existing joints, review the sizing chart, and give us a call. Whether you're building a rock crawler, rock bouncer, Ultra4 car, Jeep, mud truck, or custom off-road chassis, we'll help you select the right 7075 aluminum suspension links for your build.
At Wide Open Design, every set of aluminum links is built to order right here in Tennessee and designed to handle the abuse that serious off-road vehicles encounter every day.
Questions or Comments?
We'd love to hear your thoughts or answer any questions.