Alright, so to start with background info, I have a 1994 Jeep YJ 4.0L with a Dana 35 rear and Dana 30 front running 3.07 gears and 29" tires, I'm going to look at a set of Moab wheels and 32" BFG MT KM1's this Thursday the moab wheels are 17" there stock off a jk rubicon, I know I'll need wheel adapters, I can get them for 500$ rims and all, I want to go up to 4.10 gears and I want a locker in the rear, if I lock the rear do I have to lock the front? And what would you guys recommend as a locker I don't want to spend to much so I was thinking Detroit tru trac seeing as it's 400$ but I'm also looking at a powertrax lock right locker as well, theyre both about same price and I don't want the locker to hit to hard on the street, but I can't afford an e locker or air locker, so what do you guys think? It's a daily driver and a weekend offroader!
and will 4.10's work really well with the 32's cause I know 3.07's won't be really good and I don't want to compromise fuel mileage to bad! I know I drive a jeep no such thing as fuel economy but I need what I can get but I'm willing to compromise a little for performance.
I upgraded my otherwise stock Jeep TJ Sahara in two increments.
First, the stock 30X9.5X15 tires were replaced with BFG 31X10.5X15 ATs. The stock Jeep did pretty well with the tire upgrade alone when combined with the stock limited slip rear end and open front end. But, in some situations, I had to drive the Jeep a bit harder than I cared to due to tire slip, and lack of low end torque, etc. I also noted that the low end was not all that low, and the minimally taller tires hurt the low end power a bit.
To improve performance further, I decided to upgrade the differentials and gears. After a lot of research and advice, I decided to replace the stock 3.07 freeway fliers with 4.10 gears. I made this selection as my ultimate plan is to get 33" tires. As for differentials, I went with the Eaton E-Lockers front and rear. During installation, I had to upgrade the rear axels due to a compatibility issue with the Eaton E-Locker, so that was a few bucks that I did not intend to spend.
Overall, the offroad performance improved substantially :shock: due to the change in gears and the addition of the E-Lockers. This Jeep will now go pretty much everywhere I've so far wanted it to go, and I have not had to push the Jeep quite so hard. IMO, the rear locker was a must, but the front locker was gravy on the biscuits
. The E-Lockers are easy to control with the flip of a switch, and I can switch them front/rear and on/off independently. Switching on/off the front locker is a nice feature, especially when making sharp turns. With some lockers, you don't get control over the lock up like you do with the E-Locker or ARB.
On the road, the change in gears from 3.07 to 4.10 with the 31X10.5X15 tires has increased the RPM to MPH ratio quite a bit. At 55 MPH, the engine is taching up much higher than I prefer
for sustained driving, so that is something you might want to think about. I don't drive mine on the road much, so its not a huge problem for me, and one that will go away if I ever get a lift and 33X12.5X15s (my long term plan).
I keep rethinking my next lift/tire upgrade due to lack of $$ and the loss of stability that could come with those changes. I guess I'm debating if I want to keep to backroads, or do more of the rock crawling stuff.
I found the color coded gear charts in the Quadratec catalog helpful. I suggest you consult a chart like that to see what your RPM change will be with the gears you have proposed, and then go out and run your Jeep at the RPM before you make the switch, just to see how it will sound/feel/tach. I wish I had done that before changing gears as I might have done the lift first before doing the gear work.
