Kris

I'm looking to buy a new Jeep but I'm still making up my mind whether to purchase a JK or a TJ so bear with me for a minute. This will be my first Jeep!


Let's assume a '07 JK X, 6-speed manual, 3.21 rear end, 2.72 transfer case.

Am I correct in assuming that 4-Hi powers all 4 tires using a 1:1 ratio through the transfer case?

Am I correct in assuming that 4-Lo powers all 4 tires using a 2.72:1 ratio through the transfer case?

2wd just powers the right rear with a 1:1 ratio through the transfer case, correct?


So what's all this that I'm hearing about lockers? If the vehicle is 4wd then aren't all 4 wheels being driven in 4wd hi or lo?

If not, then which wheels receive power in 4wd with no lockers? I assume you need a front AND a rear locker, correct?



Sorry for all the questions, like I said, I'm a complete n00b but I'm willing to learn!

Caboose

no idea what ur talking about, but i heard the TJ lifted gets about 10 mpg, a JK gets around 15-17 with 35's...thats what did it for me.

degenerate

without locking the front and rear diffs, you will have one front power wheel (drivers side) and one rear power wheel (passenger side) in 4wd.

you don't need to lock them both at the same time. lot's of people will recommend a front locker first. i am one of those people.

Renegade

2WD sends power to the rear axle. With an open differential, both wheels recieve equal power until 1 wheel has less traction, then that wheel will begin to spin. The same goes for the front in 4WD. The "drive wheel" theory is a bunch of crap. The reason 1 wheel is more likely to spin on flat ground is due to the torque applied to one side of the vehicle by the motor revving creates less tracion on the other. In an eneven terrain setting (off road), this doesn't apply. If you have a limited slip dif in the rear, both wheels recieve equal power again until 1 wheel has less traction, then the clutch pack will continue to send power to both wheels up to a certain point where the friction in the clutch pack is overcome and the wheel with less traction will still spin. A locker will send equal power to both wheels at all times. Both JK's and TJ's are available with open difs, LSDs, and lockers. The advantage that the JK has is the Brake Lock Differential feature associated with the ESP/Traction Control System. It uses the brake system to mimick a limited slip in the front and rear. Good luck with your decision.

Kris

Ok, I think I understood that. So, bone stock, in 4WD Lo, I'll have the right rear and front left driving the vehicle. Technically 4WD is not what it claims to be!

So from your explanation, if the front left slips then the front right will drive the vehicle (as an open diff)?

Is the factory LSD or locker really worth anything? I know the aftermarket pieces are stronger but I'm not that hardcore.

degenerate

precisely!

no, if your diff is open, and your power wheel slips, your power wheel slips. that's it. with an LSD, the clutch packs will come together and provide power to the opposite wheel. with a full locker, if one wheel is slipping, that means they both are. knuckle up and pray.

with the traction assist and esp, i'm really not sure it is worth it. a selectable locker is worth it, but they make it a requirement to get the e-disco for the swaybar at the same time, which i have come around on (love it!), but dissuades a lot of people.

Renegade

THERE IS NO SUCH THING AS A "DRIVE WHEEL/POWER WHEEL!"

Renegade

LSD: not really
Locker: YES!

degenerate

...semantics...

Kris

Sure there is! My 8 year old daughter has a pink TJ. I need to charge the battery so she can ride it!


Thanks for all the help guys! Looks like I'll probably either skip the factory LSD/lockers and go aftermarket or I may just order the factory locker. Decisions, decisions........