Rooty

I went from 373's to 410's in a 3/4 ton dodge ram. Big waste of money the rpm differance was less than 200 and the pulling power was hardly noticeable. The mpg was the same. If your going to be a bear be a grizzly

Doc_D

Around here traffic on the highways moves along at 80 mph. At 80 mph I'm probably at 2,900 rpm. There's nothing wrong with that and it won't hurt the vehicle. But it does feel a little buzzy. It's absolutely zero issue. But if I was a sales person who was on the highway for hours every day or I drove cross country then 4.56s might make highway driving a little more relaxed and comfortable.

Doc_D

I should also mention that regearing isn't just about improving performance in a 6 speed. It's about overall driveability. When I was running 35s and 4.10s and was in slow moving traffic I'd have to be on the clutch and off the clutch constantly with lots of slipping because 1st gear was effectively too tall to drive at slow speeds. Now with 4.88s I can drive along at 1 - 2 mph with the completely clutch out with no problem.

I also hardly have to slip the clutch at all to get the rig moving from a dead stop. I can actually very easily get the truck moving without touching the throttle and barely slipping the clutch. So your clutch will thank you too.

With 4.88s I actually have the option of using 1st or 2nd gear from a stop.

When I was on 4.10s the gears were spaced too far apart. I'd often find myself cruising at a speed that was too fast for one gear but too slow for the next. I'd upshift, the jeep would bog down and I'd immediately have to downshift again. That never happens with 4.88s.

Crawling and engine breaking in 4 low is vastly improved as well. My crawl with my 4:1 t-case is nuts

jeepwave

My crawl with 3.73 is messed up!!!! I swear at one point crawling down a rocky hill I almost thought I wasn't even in 4lo. My buddy was like wow what'd you do throw it in neutral and let her roll?. Nope. Just doesn't crawl very nicely.

Good info here, thanks.

Stuck between 456 and 488 but honestly I'm thinking 488 is what I'll end up doing.

RedRockJeeper

If you had 2012 you could get away with 3.73's, with a 2009 (I believe you said) 4.56's is the absolute minimum I would run.

TheTerminator

Forget about 6th gear. Now your outstanding gear is 5th.

Most likely because you're in a wrong gear, like 6th on the highway. Drop it to 5th and watch the mileage rise. I lost only maybe 1mpg or less on highway when I went to 35's, and that's on auto tranny too.

I suggest you get a new shifter knob, that shows the 5 gear transmission shift layout

This is true even on stock tires.

It's worth it if you need to engine brake on steep descents, or if you just need better 1st gear performance. For all other gears it doesn't make much sense, as you can choose your own optimal gear for whatever speed/conditions you're at. Keep in mind on automatics, 1st gear is much worse than on manuals. Even with 35's, your 1st gear is still better than an auto's and stock 32's tires. However, there are other ways to get even better 1st gear performance on the trail (than regearing), and that is by switching to a Rubicon t-case or Atlas t-case (or Rubicrawler for autos). Of course, having both will be even better, but I'm sure money is limited for most people.

Only if you're lugging your engine. You could lug your engine even with 4.88 gears, no problem, too.

TheTerminator

There will always be hills too steep to engine brake. I'm sure if you regear, you'll find them as well.

ghostjk

So he should spend two grand on an atlas transfer case and install instead of gearing his jeep to the correct gear set for his tire size? When the average cost of a regear is 1000 bucks including install and parts?

Doc_D

+1

There is a lot of silly advice in this thread from people who haven't regeared and are trying to rationalize their decision.

There are probably 1000+ posts on this forum from people who have regeared and are extremely happy with the results. In all the regear threads I remember exactly 1 person who wasn't happy. If i remember correctly he was running 33 inch tires and a 6 speed and put 5.13s in. That was just lack of running the numbers on his part.

In my opinion if you haven't regeared you probably shouldn't be giving advice since you haven't lived with the jeep both ways.

If there is someone who has regeared and isn't happy with it they should definitely chime in and give Jeepwave your opinion.

dellpjJK

If 35 is all the bigger you are ever going, then get 4.56. You'll be very happy on the highway with them as well. If you might go bigger, or dont care about the highway rpms, then put in 4.88s. Eitherway, youre better than with the 3.73s.