phljeeper

I traded a Willys with 3.73 for a Rubicon with 4.10 both on 35s and absolutely noticed the difference. The 4.10 is still a little under powered with 35s but much easier to deal with day to day. If you have the choice the 4.10 should be your choice.

kmrtnsn

All things being equal, the difference in "crawl speed" between a Rubicon and a non-Rubicon comes from the transfer-case, not the axle gearing.

jonb1032

Correct me if I'm wrong, but doesn't the "crawl ratio" come from the combo transfer case, 4-1 and the axle 4.10.

phljeeper

Definitely a combo of the two. Not very noticeable in crawl between 4.10 and 3.73 (assuming both vehicles have a 4:1 Rubi transfer case) but on the highway with 35s very noticeable.

d. gage

In what way? I currently have a JKR with 4.10, but possibly purchasing a JKUR with 3.73

jedg

This might be useful to you... It'll tell you what you have for your overall gear and you can then compare.

When you're in 2WD, the transfer case ratio is 1:1 bot a Rubicon or a regular wrangler (or 4HI for that matter)

When you're in 4LO, the TC ratio for a Rubicon is 4:1 and the Wrangler is 2.72:1

For the transmission, look up the gear ratios for your year and then use 1st gear for 4LO and your highest gear for 2WD

Keeping all things equal, change the diff ratio and you'll see what it does to RPM and at a specific MPH.1


4Lo.com :: Final Gear Ratio, Crawl Ratio, Tire Size Calculators

phljeeper

More grunt when taking off from a stop, more torque at highway speeds and overall better power from the motor. 4.10 isn't perfect as I would much rather have 4.88 with 35s but much more bearable day to day. If you have a choice take the 4.10. Just order what you want rather than settle for dealer inventory.

All that said if you plan to stick with stock tires the 3.73 will be fine.

d. gage

Thanks. I already own the 4.10, but it's on a 2 door and we've been eyeing going back to a 4 door. There's a used rubicon near me for a decent price but it's in immaculate shape, but it's 3.73... I think I'd rather have a great shape used rubicon vs a lower model, that's where I'm at now price is a huge factor.

phljeeper

If it's a great buy just regear to 4.88 and make it even better than the 4.10. Prob a $2k job but may be worth it for a good used Rubicon.

1996cc

Thats easy then. Buy the new one, swap the axles and then sell the old one. No costs other than your time for the 4.10s.