Did you guys see this

[NoMatter]

I feel both options need to be available as not all owners use their vehicle's the same way. Granted someone superlifted (or running 33 +) would most likely want a 4.56 where as the 2" guys running 32's who don't spend a whole lot of time off road/still use their ride day to day for highway trips and around town would be better suited with 4.11's to keep that final drive rpm down. No doubt the rapid acceleration of the 4.56 would be freakin sweet though!
Just sayin.

[07JeepXK]

I also agree both would be nice. If they are only making one or the other it doesn't really matter to me. But 4.56's would be great for my next rig. Hey quick question cause I can't remember. Does the QD II front axle use the same part number for the ring and pinion as the QT II?

[NoMatter]

Yes they are the same #. The QDII has a different, larger front housing. I'd imagine someone superlifted or 33's plus would upgrade before anyone else so it would be a good sales decision to produce 4.56s first.

[stites-xk]

4:56's would be nice for my soon to be 35's!

Sent from my DROID RAZR using Tapatalk 2

[07JeepXK]

I'd pull the trigger on front gears the first day they are available!

[Cloud6221]

My vote goes to the 4.56s. I think you would see a nice improvement on both 32s and 33s. The 4.11 gears are okay if you want to return to a more normal performance, but it seems like a lot of work and money just to go back to stock performance. I'm basing this on a tire to gear ratio chart and not any real experience with re-gearing.

[Matt]

You would actually have less performance than stock since those charts dont account for added weight from larger tires or additional wind resistance from the lift. To get closer to stock performance you find the equivalent gear to stock then +1 ratio... hence 4.56s are a more rounded gear for the majority of the market.

[Matt]

Epiphany .... thought it is worth noting that 3.7L owners with the NAG1 might be better suited with 4.10s; i forgot the trans gearing was steeper already for 3.7L owners. I'll put together a quick table to see how the final drive ratios work out.

Edit: heres a spreadsheet with final drive ratios
https://dl.dropbox.com/u/24438380/Gears.xlsx

You can definitely see why the jump in performance from 3.07 to 3.73 for the V6 guys is well worth it! That's like the 4.7/5.7L guys getting 4.56s BTW

Based on this information, I still think the next gear option for our platform needs to be 4.56s since the majority of owners who will do this mod aren't concerned with a 200 RPM difference on the highway, and 3.7L owners have a good option already with the 3.73s.

Then, coming out with 4.10s would be a good gear for 3.7L guys to go a bit more extreme with their gears and the 4.7/5.7L guys to be a bit more conservative with theirs.

Also, don't make the same mistake most people make by comparing the worst OEM gear option to the next step. Think about it this way... whats the best OEM gear option available in your platform? (in this case, 3.73). So now pretend you're not "handicapped" already and have 3.73s.... what gear ratio would you like to have?

I need to take back what I said here.

What I said only holds true when you're dealing with the same trans gearing. It completely escaped me last night that the 3.7L owners who have 3.07 (or 3.55 option) gears stock have completely different trans gearing.

3.07 in the W5A580 actually has (practically) the same final drive gearing as 3.73 in the 545RFE.

So, you guys with 3.07's are not "handicapped".

[07JeepXK]

Jay has 33x12.50R18 Toyo Open Country MT's on 18x9 XD SPY wheels = very heavy setup. The 3.73's we installed in his 05 WK 3.7 made a world of a difference. Like Matt said, there is no need really for 4.10s for guys running the 3.7 liter due to the nag1 trans. Especially when a 3.73 swap is so much easier since you can get a front diff for a 4.7 liter that ready to bolt in.

[NoMatter]

Matt I can appreciate what you said regarding "the majority of owners who will do this mod aren't concerned with a 200 RPM difference on the highway" I agree.
But... I do see an awful lot of threads on gas mileage (I Know we don't drive fuel efficient vehicles. Primarily why I got such a great deal 4 years ago) But to put it out there someone who has the 545RFE and sees 2000rpm @75mph with the effective higher gear ratio from their 32's is gonna crap themselves with the gas mileage at 2200-2500 rpm! I'm fortunate to live here in Colorado with plenty of wide open spaces between places so my fuel economy is a bit better than someone who is stop and go, speed up and slow down. But as they say Slow and Steady.
- Just trying to discuss..
What effect would an over geared axle drive ratio have on the (4 Low) Crawl Ratio. Would that be beneficial or negative to off road performance?