Truck and SUV owners (including Jeep Wrangler and Cherokee owners, and lifted truck owners) often customize their vehicles with a variety of aftermarket parts. A slip yoke eliminator (SYE) is an example of an aftermarket part.
So, what does a slip yoke eliminator do? Do you need one? Do you already have one in your truck? And what will the installation cost?
What Is a Slip Yoke Eliminator?
A slip yoke eliminator is an aftermarket part that replaces an OEM slip yoke in a vehicle. A slip yoke is intended to provide driveline movement over uneven surfaces and one is installed at the factory by the vehicles manufacturer.
A stock slip yoke is nothing more than a segment of the driveshaft mounted on the transfer case (recognizing that the driveshaft actually can consist of multiple lengths). The slip yoke is a spline that allows for movement that is in/out of the drive shaft. This design allows for the driveshaft U-joints to oscillate as designed.
Unlike the OEM slip yoke, a slip yoke eliminator removes the slip joint from service. The custom slip yoke eliminator assembly and specialty drive shaft completely eliminated the need for a slip yoke all together, while reducing drive line vibrations.
Simply put, two closely mounted and properly phased U-Joints compensate for the necessary driveline play to accommodate changes in terrain with a slip yoke eliminator assembly.
How Slip Yoke Eliminator Works?
A slip yoke eliminator replaces the use of a slip yoke with a shorter transfer case output shaft, which is designed to easily couple to a CV (Constant Velocity) driveshaft. This concept is particularly useful when lifting the ride height of an otherwise stock vehicle, because a slip yoke is pushed outside of its typical range of travel in such applications.
Using a slip yoke eliminator and CV driveshaft eliminates the need to use a traditional slip yoke by placing two phased U-joints in close proximity to one another, allowing for constant articulation, regardless of the terrain being navigated.
The installation of these components will also straighten out the driveline geometry of a lifted vehicle to eliminate vibrations.
The complexity of installing a slip yoke eliminator is going to vary depending on the vehicle being modified. However, it should be understood that this chore will generally require replacement of a transfer case’s tail shaft section and the installation of a new vehicle speed sensor tone ring and all necessary hardware.
And as previously mentioned, an installation of a replacement CV driveshaft will also be required.
When Is Slip Yoke Eliminator Necessary?
There is no need to install a slip yoke eliminator on any vehicle that retains a stock ride height. A slip yoke is designed to provide an ideal driveline geometry of the vehicle it is being installed on, therefore you are generally not concern for altering that geometry unless a lift kit is being installed.
In general, a slip yoke eliminator should be installed on any vehicle that has been lifted to a height at which the driveline geometry cannot reasonably be corrected with a transfer case drop kit.
This is generally the case for any vehicle with a lift of greater than 2-inches. Although almost all vehicles with a lift of greater than 4-inches will require the use of a slip yoke eliminator.
How to Know if You Have a Slip Yoke Eliminator?
If you want to know if your vehicle has a slip yoke eliminator, the most defined way is to visually inspect it. If a slip yoke is being used, you’ll see a splined section of a driveshaft connecting a vehicle’s main driveline to the transfer case output shaft.
In many cases, the Teflon-like coating that usually coats these splines is also visible. Typically, it is a blue colour a slick-touching texture.
To identify the slip yoke eliminator, you will see two separate U-Joints fairly close, in what is not a reasonable distance away from the output shaft housing of the transfer case. The U-Joints are put together without the need for the slippage that a driveline’s slip yoke provides.
Slip Yoke Eliminator Installation Cost
The actual cost to install a slip yoke eliminator will widely vary per truck or SUV make and model, as far as parts and labor are concerned.
Generally, Jeep Wranglers and Cherokees have many more slip yoke eliminators available than pickups like a Chevy Silverado or Ford F150, and therefore will vary more in parts costs because of that reason.
Typically, most folks are spending somewhere around $800-$1,100 to install an aftermarket slip yoke eliminator and custom CV driveshaft. Because the majority of costs associated with a slip yoke eliminator installation is in the parts and it should not take more than 7 hours in labor, the only labor costs are typically between $150-$400.