How to Determine the Diameter of a Trailer Axle
Question:
I need a conversion kit to raise the trailer I just bought. I am trying to figure out which size axles I have. If I measure the current distance across the U bolts it is 2 5/8. I am assuming I have the 2 3/8 axle is this correct?
asked by: Larry
Expert Reply:
Measuring a round axle can be difficult. You would need a set of dial or digital calipers to get an accurate measurement. Using a tape measure would not be accurate enough. Calipers are available at discount tool shops. Nicer ones can get a little costly. But if you don't need precise measurements of things often an inexpensive analog model will work just fine.
Sometimes you can go by the axle capacity but not always.
Typical Axle Diameters Based on Axle Capacity
1,000-lb - 2,000-lb Axles: 1-1/2" - 1-3/4" diameter
3,500-lb Axles: 2-3/8" diameter (can have a 3-1/2" diameter, but rarely)
6,000-lb - 7,200-lb Axles: 3" diameter
8,000-lb Axles: 3-1/2" diameter
9,000-lb Axles: 4" diameter
10,000-lb Or more axles: 5" diameter

Product Page this Question was Asked From
Dexter Trailer Springs Over-Under Conversion Kit
- Trailer Suspension Parts
- Alignment and Lift Kits
- Boat Trailer
- Camper
- Car Hauler
- Snowmobile Trailer
- Utility Trailer
- Double Eye Springs
- Round Axle - 2-3/8 Inch
- Single Axle
- Dexter
more information >
Featured Help Information
Instructions
Continue Researching
- Shop: Dexter Trailer Springs Over-Under Conversion Kit
- Q&A: How to Measure Pop Up Camper Axle Diameter to Pick Out an Over-Under Axle Kit
- Q&A: Axle Over-Under Conversion Kit for 2-3/8 Inch Diameter Axle
- Q&A: Can I Use a 2-inch Square Block Between Spring Seat and Spring for Additional Trailer Height
- Q&A: How Much Height is Gained Using a Dexter Over-Under Conversion Kit
- Search Results: k71~384~00
- Search Results: trailer plug
- Article: Trailer Wiring Diagrams
- Shop: Trailer Hitch
- Shop: MORryde Suspension Upgrade Kit for Tandem Axle Trailers - 2-1/4" Long Shackle Straps
- Search Results: trailer suspension parts
- Q&A: Lug Nut Torque Chart for Trailer Wheels
- Article: How to Accurately Measure Trailer Leaf Springs
- Shop: Dexter Heavy-Duty Suspension Kit for Tandem-Axle Trailers - 1-3/4" Wide Double Eye Springs
- Q&A: How to Determine Hanger Spacing for Tandem Axle Trailer Suspension with 26 Inch Springs
- Search Results: trailer leaf springs
- Video: All You Need to Know About the Dexter Trailer Springs Over-Under Conversion Kit
- Article: How to Raise Your Travel Trailer Height
- Shop: MORryde Suspension Upgrade Kit for Tandem Axle Trailers - 3-1/8" Long Shackle Straps
- Search Results: trailer tires and wheels
- Video: 4-Leaf Double-Eye Spring for 4,000-lb Trailer Axles Spec Review
- Q&A: What is the Best Grease for Trailer Bearings
- Article: How to Measure Your Trailer Wheel Bolt Pattern
- Shop: Suspension Kit for Tandem-Axle Trailers - 1-3/4" Wide Double Eye Springs - 2-1/4" Links
- Search Results: trailer axles
- Video: Complete Breakdown of the Timbren Axle-Less Trailer Suspension w/ Idler Hubs
- Article: How to Tell the Weight Rating of a Trailer Axle
- Shop: 4-Leaf Double-Eye Spring for 4,000-lb Trailer Axles - 26" Long
- Search Results: trailer jack
- Video: Hands-On with the SumoSprings Trailer Helper Springs w/ Line Relocation Bracket