Gobi Wan Kenobi

Resharp, what did you regear your jeep to after 4.10s? and how do the new gears work on the interstate and hills. Tons of hills here in Indiana that are a PITA on the roadways.

And my 2 cents for thread starter, my family member has 3.21 gears and 37s (I do not recommend following in his footsteps) but all he does is road ride and drive in the city and he does fine as in not breaking the D30, but the jeep is a turtle and goes nowhere fast.

resharp001

I’d start by saying this….my jeep is no longer daily driver. I bought a small POS commuter car a few years back just cuz once my odometer rolled 50k miles, I started getting depressed about how fast that was adding up. I put 15k miles/yr on just driving to work, then add in wheelin’ trips and long distance type trips for jeepin’ and I was well over 20k/yr. So, my jeep is mainly a toy/hobby now. I drive it on the weeknights/weekends, and sometimes to work when I just need a mental pick-me-up.

I don’t have the Rubi TC, and my wheelin’ style if fairly aggressive, playing in the rocks. So, I went from 4.10’s to 5.13’s. I live just a bit west outside of Fort Worth, and it’s pretty windy out my way on the interstate, and I’m typically driving ~75mph out there. With 4.10’s, 3.6L, and automatic....I basically had no 5th gear. I only saw 5th gear maybe on long road trips with no wind on flat land…..and could cruise along at 2100 rpm, but more often than not I was in 4th gear and downshifting to 3rd just to pass. The low end around town didn’t kill me near as much as the high end. I think kinda get used to sluggish around town….but as highlighted above…you are stressing your transmission.

Regearing to 5.13 was night and day difference. Don’t expect it to drive like you got a supercharger or turbo, but it drove so much better…like it should have. I would say that I’m geared a bit low for most people’s preference, but I was willing to sacrifice a bit for the offroad benefits. I love the low end power on the pavement, and I love the offroading crawl. Higher speeds on the pavement are the downside. Typical interstate speeds put me cruising at 3k rpm, which in a perfect world is a little high. The engine hums a decent bit and the fuel gauge likes to drop fast. The 3.6L is not quite as tolerating to higher revving rpm’s as the 3.8L seemed to be. I will say though, that sucker sticks in 5th gear on the interstate in to a stiff wind, with just an occasional downshift to 4th if you need to stop the peddle to pass. The only thing that aggravates me a little is if I stomp it to get on the interstate, the Jeep likes to hold 3rd gear for a loooong time, all the way up to ~5k rpm or so before shifting to 4th. I typically just either 1) refrain from stomping on it, or 2) ease up a bit to force a shift.

We all have different styles, uses, and geographic locations. With so many variables it makes apples to apples gearing comparisons difficult, BUT, I’d say that generally people with 37s and an 3.6L auto would probably be happier with 4.88’s. There will always be exceptions, but I think 5.13 would be too low for MOST people with the 3.6L auto. I originally had 3.73 gears and swapped to 4.10 rubi axles back in the day. TBH, there was a tiny hint of difference, but not much. I suspect that kind of difference would be the same between 4.88’s and 5.13’s. Not enough to make a big difference, but the 4.88s would shave 100 rpms off that top range probably. I’m happy with what I have, but if I had to do it all over again, 4.88’s might edge out for the win just for overall driving aspect. IDK, tough call for my situation. If the jeep isn’t seeing a lot of interstate driving, and you have hills around, you might be in that small group that would like 5.13s better. Just be warned the drawback is traveling at higher speeds.

Gobi Wan Kenobi

That was a great explanation, I appreciate the info