What are my locker options currently for an 03 with SelecTrac?

[Begle1]

I have an '03 Liberty with the 3.7, SelecTrac and automatic trans, and I just installed the ol' OME lift kit from Rocky Road.

I'd like to get some lockers next. What are the good locker options currently?

The rear differential is open currently. I have stock tires now but figure I'll end up with 245/75R16's when these wear out. (I gather those are the biggest that'd fit.) I plan to never go bigger than that. This is a daily driver that needs to go up and down muddy, rutted-up trails and occasionally also drives on wet/ muddy pavement where I very much do like to use the "Full Time" mode. I'm not rock crawling or trying to go fast off-road.


Would it be wise to use a selectable locker on the front to avoid any possible on-road handling problems, and then use an automatic locker on the rear to get three-wheel drive? If I ever get stuck on three wheels then I can activate the front locker and hope for the best?

Or is there an automatic setup that works good in the front with SelecTrac, even on-road? Am I best off just going selectable on both ends?

Thank you, I know nothing.

 

[Begle1]

Doing a lot of reading, it seems like I can find any opinion I want in terms of how badly an autolocking differential in the front affects road manners, or even in the rear.

This is my loaner car too, so I'd like to make sure road manners are as friendly as possible. I've always felt like "Full Time" mode on the transfer case has been as useful and forgiving on slick pavement as one can ask for on a vehicle without any electronic aids.

I'm trying to wrap my head around what kind of funny things an autolocker could do while cornering on slick pavement.

I'm currently leaning towards a clutch-based LSD in the rear and a selectable locker in front, or selectables front and rear, to try and make road manners as forgiving as possible... But if I would be happy with lunchboxes in the front and rear, I could certainly be sold on that due to how much easier and cheaper it would be.

 

[KJowner]

Don't lunchbox the front it will blow it to bits! The alloy housing isn't very strong.

 

[DefCon2]

Your idea of having a selectable in the front is good, but not entirely necessary. I've had Dana Truetracs in the front of most every Jeep I've had. It will only engage when a wheel spins, so you will always anticipate when it will engage. It does not negatively effect road manners or drivability. Some people are afraid that the front diff could grenade, but there would only be a risk of it if you were hammering the throttle and creating massive wheelspin. Moderate throttle would have the locker engaging before the tire could get up enough revs to create any real stress.

 

[mike]

But if I would be happy with lunchboxes in the front and rear

Excuse my ignorance, what are "lunchboxes"?

 

[DefCon2]

A lunchbox locker is a generic term for a locker that engages by itself by use of an internal planetary gear (or similar) when one wheel on the axle begins to spin. Selectable lockers engage when the push of a switch locks the gears either by an electronic servo or pneumatically.

 

[KJowner]

They aren't very nice for on road use, if you search on here you can find lots of posts about them, they are the cheapest option but far from the best for a road car. The front end is a well known weak point on the KJ, unlike other Jeeps it's an aluminium casting with modified Dana 30 internals, probably one of the weakest ever made, on the other hand the rear is a later 8.25 which is very strong & will even handle the full torque of the CRD in 2wd mode.
As I said, it's been well discussed over the years, there's a recent thread on here about fitting Spartan helical lockers that are a bit kinder to the driveline, have a search