Symptoms
4WD that engages at the transfer case but doesn't drive the front wheels, or grinding from the front axle. Comanche Club members say to check the vacuum-operated central axle disconnect before your first trail, and to lock it in or bypass it if necessary.
The fix, step by step
- Check the vacuum lines and the switch on the transfer case first.
- If the shift motor or fork is the problem, a manual disconnect kit replaces the vacuum actuator with a cable or lever, or the axle can be made permanently engaged with the right parts.
- Drain the gear oil, unbolt the shift-motor housing, fit the kit and refill with 75W-90.
Tools & part numbers
- Vacuum gauge or hand pump
- sockets
- gasket scraper
- RTV
- gear oil
Where to buy the parts
Crown RT23002 manual axle disconnect kit, 1984–93 XJ & MJQuadratec ↗Amazon ↗
Yukon YCGD30 Dana 30 diff cover gasketQuadratec ↗Amazon ↗
Hunting a used or discontinued part? Search eBay Motors for Jeep Comanche MJ parts →
Rated for a competent home mechanic with a decent tool kit. Confirm torque figures, fluids and procedures against the factory service manual for your VIN, support the truck on stands rather than a jack, and work at your own risk (disclaimer). Some parts links are affiliate links, which pay us a small commission at no cost to you.