Originally Posted by Habber
Sorry guys, I'm a bit of a newbie. Please explain when I would need locking diff. Also if someone can explain difference between sport and Rubi I'd really appreciate it.
Jeep TJ 2001 4.0 5MT
For what sounds like you intend to do you probably won't need the locking diff. The thing is though, the one time that you need them they will have been worth it especially considering the price you can get the Rubicon for.
Speaking of the Rubicon here:
In normal operation the differentials are open. This means that the tire with the best traction is the one providing the majority of forward momentum. Even when running in 4WD the axles are still open and typically only two wheels (one front/one rear) are truly providing forward momentum. With locking diff (front and rear) the axle shafts are locked together, in effect making each axle a solid drive unit and all 4 tires provide forward momentum. Or you can lock just the rear axle while in 4WD and gain that extra little bit push if needed (a situation such as having trouble getting through some mud).
The main difference between the Sport and the Rubicon are the axles, the transfer case and the sway bar disconnects.
The axles in the Rubicon are typically geared at 4.10 versus the somewhat standard 3.73 (could be 3.21) gears in the sport. From what you have described the 4.10 gears would be to your benefit since you intend to go to a 35" tire in the future.
The axles in the Rubicon also have the electronic lockers as discussed above.
The transfer case in the Rubicon is geared at 4:1 low range versus 2.72:1 low range on the Sport. The Rubicon transfer case is beneficial when off road, more specifically when the trail has off camber obstacles that need to be overcome. The lower gear ratio allows for more finess when you need to travel at a slower ground speed.
The sway bar disconnects just allows for more front suspension flexibility when going over off camber obstacles.