I have an 89YJ that I have lifted 3.5" with 33" tires and just installed the 4.0 engine swap and all works great. I would like to install some new gears, But have been told several gears will work 4.11- 456 are the main two? Because this is my daily driver I would like to install the right gears that work the best for performance and mileage, does anyone have an opinion on this that could help me? I have a Dana 35 rear & Dana 30 front and should I match the front gears with the rear or could I do the rear now and front later or am I going to have problems with 411 or 456 in the rear and stock gears in the front?

I also just received my Posi-lok system to do away with the old stock vacuum 4 x 4 engagement system. Has anyone heard any good or bad things about the Posi-Lok?

Thanks,

Josephelk

Oh NO! Please don't put the gears in one at a time.. If I did that I would pull the shifter out of the transfer case or the front driveshaft.. I'd make it where there was NO WAY to engage the front wheels!
With never going higher than 33's using a 3:73 should work fine for the best milage. If around home is hilly maybe the 4:11.. But I think the 4:56 is a bit low for that engine and only 33's.
The posi-loc is a good thing to have unless you drive over the top of a lot of heavy offroad brush and small trees.
Big JIm <img src="/forums/images/graemlins/pfft.gif" alt="" />

Big Jim is right. You have to re-gear the front and rear axles at the same time. I would run 4.11's with your engine and tire size. You would be fine with 3.73's but I think you will still be looking for more low end juice with that ratio.

Robert
Classic City Offroad

Flad landers, sheesh.
Posi lock indicates that your wheeling will be at least serious enough that you can't afford to not have 4x. How into jeeps and jeeping a given person is, is how I answer this question.
If you are sold on the virtues of jeeps and wheeling, 35" tires are next with lockers an axle swaps not far behind.

4.56 or even 4.88 is just fine with 33s assuming a 5 speed
manual tranny, if automatic 4.10 or 4.56.

Forget 3.73.
You have mountains to drive, snow to wheel (snow we have here now 24") get gears that not only suit the imediate need but future needs as well.

SD

I think you should go with the 4.11 gears rather than the 4.56 gears. I have the 4.56 gears in my trail-dedicated CJ7. Even with 35" tires, the gearing is too low for me to travel any considerable distance on the highway -- rpms are just too high at 60-65 mph. Yours would be even worse with 33" tires, especially since you say that it's a daily driver.

You could probably get away with 3.73 gears, but I think you'd be happier with the 4.11 geaars once you get off of the pavement.

Personally, I would never drive a 4x4 that had different gear ratios in the front and rar axles. That's a MAJOR screw-up just waiting to happen!

Thanks for the responses,

I think I will go with the 4.11 front and rear. What manufacture of gears is the best and what manufacture should I stay away from?

I�ve never installed gears before but I pickup on things pretty quick and I have my service manuals that I purchased when I changed out my 258 engine for the 4.0. Is this something I could do myself or should I take it in and have them installed?

Thanks again for the excellent feed back.

I would just get it done by a pro unless it's something you really want to learn how to do. You will need someone that can teach you and the special tools required to do gear installs.

Richmond gears have always worked good for me. But any name brand should do fine.

I got a 2006 Rubicon . I am getting a 5.5 RE lift and am trying to decide whether or not to go with 33s or 35s. Any opinions...?? I was worried about the 35s being to big for everyday driving.

I think I will have someone else do the gears. After the engine swap I did on my Jeep I think I will take about a year break from working on it? Ya right, I will get my gears and try them out and end up breaking something. But that�s what it's all about, Build it and break it sometimes.

Thanks again for all the good advice.