First off I just wanted to say that this is my first Thread here. I was doing some research for a friend and found this site. Seems good and being and avid Jeep owner I'll be around often.
My friend has a 99 TJ, auto. Looking to run 33s and do a gear swap. I think 4.10 should be good but he is convinced 4.56 would be better. We wheel on the weekends and drive to work and school monday-friday. Any advice would be helpful.

 

i would go 4.56 4.10 are good for 31's and 32's but for 33's i would get 4.56 because if you want to ever run 35's 4'56 would be good

 

4.56 FTW!! Do it....period!!! Always go one step higher than you "think" will be the best. You won't be disapointed!!

 

Does he want good fuel economy or better performace? 4.10's will give him good fuel economy with 33's since it will put him back to stock specs for a 28" tire and 3.55 gears. However, I've been on hill climbs with that setup and decided I needed lower gears than that. 4.56's will be like your jeep coming stock with 3.73 gears which some did. So if the thought of maybe running 35's or wanting to go and be good offroad even crosses his mind he should run 4.56. Let's face it if good fuel economy is what he is looking for he should sell the jeep and buy a honda. Also this is assuming he has a 6cly, if he has a 4cly then he needs to be debating between 4.56 or 4.88.

 

Thanks a lot I'll pass it on.

 

yeah 456 is they way to go it will give you better ability to climb and more torque when needed over the 410's

 

Not to pick, but half of your statement is true. Gears do not make more/less torque. They apply the torque given more/less depending on the ratio.

 

i run 35s on my TJ Rubicon and 4:10 gears... its got the 4:1 low range and it makes a huge difference but in 2 wd its got plenty of pep!
On my XJ. when i run the 33s.. 4:10s . it ll make it run like it did when i was stock. 4:56 and you ll lose the highway speeds you used to have.
If this is your daily driver and your weekend warrior? 4:10 gears
If this is your everyday warrior.. as in you intend on going offroad every weekend then yeah.. more torque.. 4:56.

http://www.4lo.com/calc/geartable.htm


Mark

 

thanks for that link. That should help persuade my friend into the 4.10s. My XJ still has the stock gears, pretty sure there 3.56 or something close. I'm running on 31s with plenty of pep.

 

4.56 definitely. i find myself wanted 4.88s, cant have too much gear

 

I'm all about low gearing but an automatic wrangler doesn't have overdrive which kills the highway characteristics and fuel economy right off the bat. If he does a lot of highway driving I would say 4.10s but if he doesn't drive far or at high speeds, go for the 4.56s.

 

4:10s for 31s 4:56s for 33s and 4:88s for 35s