Can I use spacers on a four wheel drive vehicle?
Wheel spacers can be used safely on four wheel drive vehicles when correctly sized, properly installed, and checked regularly. However, there are several 4WD-specific considerations including CV axle angles, hub geometry, and engagement mechanisms that are worth understanding before adding spacers to your setup.
Spacers are a popular fitment accessory across all drivetrain configurations, and many four wheel drive truck and SUV owners run them successfully as part of their builds. That said, there are some considerations specific to 4WD and AWD vehicles that are worth understanding before adding spacers to your setup. Here is what you need to know.
Yes, Spacers Can Be Used on 4WD Vehicles
Wheel spacers are used on four wheel drive trucks and SUVs regularly and are considered safe when they are correctly sized for the application, made from quality materials with precise machining, properly installed, torqued to specification, and checked regularly as part of ongoing maintenance. The fundamental principles of safe spacer use apply equally to 4WD vehicles as they do to two wheel drive applications.
CV Axle Angle Considerations
One of the most important 4WD-specific considerations when adding spacers to the front axle is the effect on CV axle angles. On four wheel drive vehicles the front wheels are driven through constant velocity axles that flex through a range of angles to accommodate steering and suspension movement. When spacers are added to the front wheels of a 4WD vehicle, the effective width of the front track increases, which changes the angle at which the CV axle operates.
For most moderate spacer thicknesses in the range of 25mm or less, this change in CV axle angle is typically within acceptable limits and does not cause issues with standard daily driving and moderate off-road use. However, larger spacers, particularly on vehicles that are already lifted and therefore already operating their CV axles at steeper angles, can push the CV axle angle beyond what it was designed to handle comfortably. Excessive CV axle angle can cause clicking noises particularly during turns and acceleration, accelerate wear on the CV joint, and in severe cases lead to premature CV axle failure.
If you are planning to run larger spacers on the front axle of a lifted 4WD vehicle, consulting with a qualified mechanic or the fitment team about the specific implications for your vehicle and lift combination is a worthwhile step before purchasing.
Hub and Engagement Mechanism Clearance
As discussed in relation to center caps, some four wheel drive vehicles are equipped with manual locking hubs or other hub engagement mechanisms that protrude from the center of the hub. While this is more of a center cap consideration than a spacer consideration, it is worth confirming that the spacer you choose is compatible with the hub configuration on your specific 4WD vehicle and does not interfere with the engagement mechanism or any related hardware.
Front vs. Rear Axle Considerations
On four wheel drive vehicles, the rear axle does not have the same CV angle considerations as the front since the rear axle does not need to accommodate steering movement. Adding spacers to the rear wheels of a 4WD truck or SUV is generally more straightforward from a mechanical standpoint than adding them to the front, and the same sizing and installation principles that apply to any rear spacer application apply here.
When adding spacers to all four wheels of a 4WD vehicle, using the same spacer thickness on both axles is the standard approach. Running different spacer thicknesses front and rear can change the handling balance and track width asymmetry of the vehicle in ways that are worth understanding before making that choice intentionally.
Bolt-On Spacers Are the Recommended Choice for 4WD Applications
For four wheel drive vehicles, bolt-on spacers are the strongly recommended choice over slip-on spacers for most applications. The more secure independent fastening of bolt-on spacers is particularly relevant on 4WD vehicles that are used off-road where the wheel assembly is subjected to more aggressive impacts, articulation, and stress than typical on-road use. The additional security of having the spacer independently bolted to the hub before the wheel is mounted provides a more reliable and robust assembly for demanding use conditions.
Re-Torquing and Regular Checks Are Essential
Re-torquing all spacer and wheel hardware after the first 50 to 100 miles of driving following installation is essential for any spacer application and is particularly important for 4WD vehicles used off-road where the additional stresses on the wheel assembly can accelerate any initial settling. Checking torque periodically as part of regular maintenance keeps the assembly secure and catches any loosening before it becomes a safety concern.
Test Fitting Before Driving
As with any new wheel and spacer installation, performing a full test fit before driving is a critical step. Check clearance at the outer fender edge at full steering lock in both directions, verify inner clearance around suspension and brake components, and lower the vehicle onto the tires to assess clearance under the weight of the vehicle before taking it out for the initial drive. Suspension compresses while driving which can change clearances significantly compared to a static inspection, making thorough test fitting especially important.
Have Questions About Spacers for Your 4WD Vehicle?
If you have questions about running spacers on your specific four wheel drive truck or SUV, want help selecting the right size and type, or want to understand the implications for your specific lift and suspension setup, the customer support team is happy to help. You can reach out through the Contact page on the website and a team member will be glad to assist.