Overview
The Advance Adapters 50-7906 is a transfer case slip yoke eliminator kit for the NP231 transfer case. A slip yoke eliminator replaces the sliding slip yoke on the transfer case output with a fixed yoke, which lets a damaged rear driveshaft be changed on the trail without losing all the transfer case lubricant.
It is for Wrangler NP231 transfer cases and is designed to reduce noise, vibration and wear on a lifted NP231. The heavy-duty rear output shaft offers a 54% increase in torque capacity and an 18% larger spline diameter.
Key features
- Fixed yoke replaces the slip yoke on the NP231 transfer case
- Heavy-duty rear output shaft with a 54% increase in torque capacity
- Spline diameter 18% larger than before
- Aluminum rear output housing included
- Allows a damaged driveshaft to be changed on the trail without losing all the lubricant
Driveline after a lift
A slip yoke eliminator changes the driveline by removing the sliding yoke from the transfer case output. The rear driveshaft then runs at a fixed length, so the angles at each joint need to be checked once the lift and driveshaft are assembled. Driveline vibration on a lifted Jeep often comes from angle problems rather than the eliminator itself, which makes measurement a useful step.
Because the fixed yoke pairs with a CV-style rear drive shaft, plan the shaft choice before disassembly. Inspect the transfer case output bearing and seals while the housing is open, and replace worn U-joints so the new driveline is not limited by old parts. Recheck the driveline after the first few trail runs.
- Measure driveline angles after installation
- Inspect output bearings and seals while open
- Recheck the driveline after the first trail runs
Specifications
| Brand | Advance Adapters |
|---|---|
| Part number | 50-7906 |
| UPC | 808331005240 |
| Transfer case model | NP231 |
| Torque capacity | 54% increase over the standard output shaft |
| Spline diameter | 18% larger |
| Replacement yoke type | 1310 CV style yoke |
| Included parts | New tail shaft, new output shaft, new extension housing |
| Other components | Aluminum rear output housing, bearings, seals, snap rings, bolts |
Vehicle fitment
It is a direct fit for the NP231 transfer case and uses a 1310 CV style yoke.
Transfer cases other than the NP231 are not covered. Check your transfer case model and Wrangler year before ordering.
Installation notes
Some models may require the mode fork shift rail to be shortened, so check the mode fork before assembly. A CV rear drive shaft is required with this kit. Work under a raised Jeep only with jack stands on level ground.
What’s included
The kit includes a new tail shaft, a new output shaft, a new extension housing, an aluminum rear output housing, bearings, seals, snap rings, bolts and instructions.
Not included: the CV rear drive shaft, which the kit requires.
