Re-gearing axles

[Sal-XK]

Check this out http://www.differentials.com/Catalog...?pageNumber=12

[07JeepXK]

Id love to have to 4.11's in my XK right now. If only I knew they would definately work. I dont have the money to be the test vehicle. Unless someone wants to buy me the gears and install kits since I can get them installed for free....lol

[Sal-XK]

I'm guessing the axles pretty common being used in other vehicles that it should work. I don't have a need for them myself but now the info is here.

[07JeepXK]

The only vehicles that I know of with our front differentials are the Grand Cherokee (WK) and Commander (XK). Our front axle wasnt used in a lot of vehicles like other axles.

[Matt]

What gears do you guys have stock?

[07JeepXK]

Sal and I both have 3:73's. You also have 3.73's. Since Im lifted with larger tires a set of 4.10's or 4.11's would pretty much put me back to stock which would be great for the hilly adventure I have to do once a month for the Army out towards NY City.

But 4.56's would also be amazing for future plans to the XK.

[Matt]

Yeah I knew I had 3.73s... wasn't sure if you guys had a different package that came with 3.42s or something.

Ill have to look up our trans gears to be sure... but from my experience, going from 3.73 to 4.10 is very rarely worth the cost. Especially in these vehicles. ... 3.73s should work well offroading with up to a 32" tire when backed by the 4.7 or 5.7 (depending on the trans gears). If you're going to a good sized 33 then 4.10s would indeed be better.. but at that point you might as well go with 4.56.

From a mathematical standpoint, 4.10s with 33s gets you back to stock gearing, but not stock power. The increased weight and rolling resistance and moment of inertia still eat away at performance. Going with 4.56 in this case will utilize some mechanical advantage AND bump up the power output for a given speed (you know what HP and torque curves look like) which will help compensate for those power robbers.

4.30 would actually be ideal for 33s.... but its not a common gear.

....again, I haven't looked at the trans gears yet but I doubt its going to be far from what I'm expecting.

[Sal-XK]

Ya 4:56 would be nice when I get my 35's installed.

[07JeepXK]

I dont think I totally agree with your statement. I do agree that going from 3.73's to 4.10's isnt that big of a jump. However if they ever do come out with gears for our Jeeps and 4.10's are all thats available then it would definately be worth it to me since I would only have to pay for parts and can get them installed for free. Now dont get me wrong 4.56's would be a better option since I do plan on going with bigger tires but ill take what I can get.

My XK does fine with 3.73's and 32's while off roading but I ALWAYS stay in 4 Low. If I had 4.10's though, my XK would be better off on the Mountainous roads on my 5 1/2 hour drive to play Army once a month and result in slightly better gas mileage too.

BTW: did the math....it looks like 4.10's with 32's would be equivalant to stock gearing....not 33's.

[Matt]

Yeah I said its usually not worth the cost.... if you get them installed for free and that's all that's available, then that's a different story altogether. Devil is in the details.... I do my own installs so it'd be free for me too, but I wouldn't go through the trouble unless I was putting 4.30 or 4.56 in.

Are stock tires 245/65 or 245/60? If they're 245/65 then equivalent tire size is 32.4" which is what most 33s measure... so we could split the difference and say 32 to 33.