Assembly and Installation Tips: Understanding Jam Nuts and How to Use Them
Posted on: March 29th, 2022

Jam nuts, or lock nuts, have been used for well over 150 years to securely lock bolts in place on machinery. Today, we use the same proven method to help our products stay in place use after use. So what are jam nuts? What's the right way to assemble them when you're putting together a heavy metal product like a hitch-mounted carrier?

What are Jam Nuts?
A jam nut is a secondary, low profile nut that is threaded onto a bolt and tightened against a primary nut in order to lock them both into place using tension against the bolt thread.
Jam nuts are about half the size of a regular nut. The two nuts are both screwed onto the bolt and are then tightened against each other.
What are they used for?
The primary reason jam nuts are used is to prevent vibration from loosening the bolt and creating movement. At Discount Ramps, most of our hitch-mounted products feature jam nuts to reduce carrier jostling and to keep connections strong, even after miles on the road. They can also be used to reduce the risk of thread stripping, especially if the threads are galvanized.
How do they work?
By tightening one nut on top of another, the threads jam together and create tension that pulls in opposite directions and reduces the chance of the bolt self-loosening.
How our jam nuts are different
Our mobility carriers and motorcycle carriers feature a refined, more user-friendly jam nut design. Instead of a loose jam nut, ours are welded in place against the steel carrier hitch tube so that the only nut you have to worry about it the single large nut. Not only does this decrease the chance of misplacing the vital, thinner jam nut, it also means it’s already in position so that the bolt order is correct every time.

What Discount Ramps products use jam nuts?
Many of the motorcycle carriers, mobility carriers and cargo carriers we carry use jam nuts to secure hitch-mounted pieces that will experience a lot of vibration on the road. The jam nuts keep everything in place where regular nuts are more at risk to fall out without very regular tightening.

Silver Spring
- SC500-AF Deluxe Folding Mobility Carrier
- SC400-V2 Mobility Carrier with 42" Loading Ramp
- SC500-V3 Deluxe Folding Mobility Carrier with 59.125" Loading Ramp

Harmar
- AL001 Mobility Carrier with Folding Ramp

Tilt-A-Rack
- 350-ARV-Mini Mini Mobility Carrier
- 350ARV Full Size Mobility Carrier
- 500ARV Full Size Mobility Carrier
- TWSC-350 Premium Mobility Carrier

Elevate Outdoor
- UC500-XL Heavy-Duty Cargo Carrier with Ramp
Common mistakes to avoid when using jam nuts
Our customer service team has years of experience helping customers properly install and troubleshoot their hitch-mounted products, and they want you to avoid common mistakes so that your carrier is assembled and installed as safely and securely as can be.

Mistake #1: Not setting the proper bolt depth.
Solution: Thread the bolt as far as you think it needs to go in order for the carrier to be level. If the jam nut is being used at a folding bracket, such as below, make sure that when the carrier is folded down completely it is level and not sloping down away from the hitch.
Mistake #2: Not tightening the nut against the hidden, welded jam nut.
Solution: Finger-thread the bolt as tight as you can while making sure that the bolt stays at the ideal depth. When you can’t tighten it anymore with your fingers, use a hand tool to fully tighten it against the hidden, welded jam nut.
If you follow the steps and still find that you have installation questions about your hitch-mounted carrier from Discount Ramps, give us a call! We will be happy to assist you with assembling and installing your Discount Ramps product.