The SYE kit addresses the driveshaft vibration that appears on non-Rubicon JKs at lift heights above 3" — it modifies the NP241OR output shaft to accept a slip yoke that allows a proper CV driveshaft to operate correctly at steep angles.
The non-Rubicon JK uses the NP241OR transfer case, which leaves the factory with a specific rear output shaft configuration that works correctly with the factory driveshaft at stock ride height. When you lift the JK above approximately 3", the angle between the transfer case output and the rear differential pinion increases beyond the design limit of the factory U-joint-style driveshaft. The result is a vibration that appears at highway speed and worsens under acceleration — sometimes described as a buzz or shake that can be felt through the floor and seats. The SYE (Short Yoke Eliminator) kit replaces the factory output shaft with one that accepts a slip yoke and mates to a properly built CV driveshaft, which handles the steeper operating angle without transmitting vibration.
Rubicon JKs with the NP241J transfer case do not need an SYE — their output shaft configuration is different and does not exhibit this issue at typical lift heights. Non-Rubicon JKs on lifts between 1.5" and 3" often live with some vibration or address it with a slip yoke eliminator and stock driveshaft. Above 3" of lift, the SYE and a custom CV rear driveshaft are the correct solution. The Teraflex SYE at $299 is the most commonly installed kit — it's engineered specifically for the NP241OR and includes the output shaft, slip yoke, and hardware needed for the transfer case modification. Advance Adapters at $279 is the budget alternative; the Tom Wood's kit at $349 includes additional precision machining that shows in smoothness on the final installation.
The SYE kit alone solves the transfer case output shaft issue, but it must be paired with a new rear driveshaft that is built as a CV (constant velocity) design. A standard two-U-joint rear driveshaft will still vibrate at the steeper operating angle even with the SYE installed — the CV design cancels the operating angle at both ends and delivers smooth rotation across a wide angle range. Tom Wood's Custom Driveshafts are the most commonly recommended source: they build to your exact vehicle measurements and lift height, and a custom shaft from Tom Wood's typically runs $350–$500. Plan for both costs together — the SYE without the correct driveshaft is an incomplete fix.
Installation requires removing the rear driveshaft, dropping the transfer case a few inches (or fully removing it depending on body clearance), and performing the output shaft swap with the case outside the vehicle or in place on a transmission jack. The transfer case is heavy (50+ lbs) and awkward — a transmission jack is not optional equipment for this job. Torque specifications for the output shaft retaining hardware are critical; undertorqued hardware has caused output shaft failures in the field.
| Part | Vendor | Est. price |
|---|---|---|
| Teraflex SYE Kit for NP241OR Transfer Case (JK) | Teraflex | ~$299 |
| Tom Wood's Custom Driveshafts SYE Kit for NP241OR (JK) | Tom Wood's Custom Driveshafts | ~$349 |
| Advance Adapters SYE Kit for NP241OR (JK) | Advance Adapters | ~$279 |
Written and maintained by an AZ wheeler and driveway wrencher. Always cross-reference your factory service manual — modifications affect vehicle safety and warranty. Work at your own risk.