nthinuf

Locking the front and leaving the rear open will not cause any problems, other than the normal driveability issues associated with having the front end locked. (There is a new debate every few months on whether locking the front or rear is better when you can only afford to do one end.)

Assuming you do have 3.21's (?), now is a good time to consider adding some form of traction, instead of spending that $80 or $90 or whatever on another open carrier. Which way you go with it will depend on your use and needs. If you need a full locker and can afford the $1000 +/- price tag, a selectable is a great choice. If you do a lot of wheels-in-the-air offroading and don't drive a lot of snow/ice, a front detroit may be a good call. If you do not do a lot of heavy offroad, a truetrac is a fantastic option considering the cost vs performance. (around $390 for the d30 truetrac at Summit. You can get a pair for less than the cost of a single selectable)

blackstang3o2

What would be the benefit of a truetrac in a newer jk with traction control. If one wheel slips with trac on power goes to other wheel correct? Same function as a true trac.

horrocks007

Momentum. That breaking on the other wheel slows you down. It may pop you out of otherwise not moving, but a mechanical limited slip will work without breaking.

This comes into play in mud, sand and snow.

Limited slip is nice, I got a mopar tracloc put in mine at no charge from the shop when I got my regear. Truetrac is better I bet though.

In hindsight, I wish I just put a locker in the rear and a true trac up front. Best combo for my needs, current and future.

Sahara Lee

Don't forget to change the seals while the carrier is out. Get those plastic spacers too. Might as well change the U-joints and ball joints too.

nthinuf

I guess we are roaming away from the initial gearing topic, but, it depends on your actual usage and needs. A quick question for you would be: if the computer controlled traction was good enough, why are both limited slips and full lockers offered from the factory?

As you noted, with an open diff, you'll have a tire that does have traction, but has no power to move the vehicle, and a tire that does not have traction, but is getting all of the power and spinning freely. At some point, the electronics decides to engage the brakes on the spinning tire, which sends "some amount" of power to the tire with traction, which 'hopefully' gets you unstuck. But how does this help if you actually needed momentum instead of having the brakes on, or needed the tire with traction to have more power than it gets through the braking transfer? Onroad or light offroad, bld may be all you need. But many people find that bld is not sufficient for their usage, either due to the timing of the transfer or that not enough power is actually being transferred.

To me, it seems kind of like the negative to selectable lockers. You drive with open diffs until you are stuck, then you reach down and push the button to lock the diffs and try to get yourself out. If you had known you were going to get stuck, you would have reached down and locked the axles before you got there. But then again, you didn't know you'd be stuck, so how could you have known to engage the lockers... (maybe that is over-simplified or understated or whatever, but ya know) The truetrac on the other hand (or any automatic locker), is always on. You never have to think about it. You aren't stuck before it thinks "hey, maybe I should apply the brakes and get to work", it is always helping whether you knew you needed it or not.

And as noted above, unlike the stock limited, the truetrac uses gears instead of clutches, so it will never wear out and be utterly useless.

Matthewd5

OP

trust the charts + listen to Northridge

I have 5.13's on a six speed manual 2012 and 37's

The 5.13's are perfect for my Jeep but if I were a commuter I'd probably wish I had gone with something else like 4.88

The chart told me that 5.13 was better off road and ok on road

4.88 were ok off road but better on the highway

My goal was 90% off-road performance

Matthew