jetmechabq

I do have a rubi. However i'm concerned that 5.13's are to thin as i like to rock crawl. I'm still thinking the 4.88's are best. I would like to hear more from those who did a gear change. Thanks for the feedback everyone.

c17loadmaster

I did rehear to 4:88's. I was just pointing out the potential problems with 5:13's. If you go 4:88's and 37's you will likely get your stock power band back, which is optimal.

adamisadam

So are 5.13s in a Rubicon just as strong as 4.88 in a non Rubicon?

c17loadmaster

Id say so because you have the larger set in your d44 front

RFL83-13

I am a differential mechanic, and I tell most of my 4x4 customers to go to ringpinion.com (randys ring and pinion web site). They have a gear calculator. You plug in your info and figure out what would bring you back to stock, or above if that's what you want. Also, when you lower the ratio the pinion does get smaller (just in the number of teeth). So in order for the ring gear to make contact it has to be thicker. So really your stock ring gear is thinner. They also make different carriers to support different ratio ranges also. It's not that big a deal though. When you change your ratio you are creating less stress on the gear set anyway. Don't forget, www.ringpinion.com. and you should find out what your last gears overdrive is, and what rpm you operate in at the desired speed. You will need it for the calculations.

RFL83-13

You shouldn't be so concerned about strength. If you want something stronger then wait for the rehearing and get some Dana 60's. What I'm saying is, what makes a differential strong is its size. That's what big trucks have big diffs. Big commercial trucks can run 7.30 ratios and that doesn't mean that there not strong. The diff is gigantic and that is what makes it strong. All you need to be worried about is ratio. Do you understand what I'm saying?

jetmechabq

I do I think I might get 60's front and rear but that will be down the road.

jetmechabq

I'm leaning the same way with 4.88 I think I'm 90% sure.

ttfhell

I've got a '12 auto Rubi with 37's and 4.88 done by Evo. Noticeable difference than stock gearing. Would not go any larger on the gearing. Pushing 3000 rpms at 70. Think it's perfect now. 4 Low absolutely crawls.

Ecb12

That seems kinda high. The stock 3.73 turn 2300 and 4.1 turn 2500 with stock rubi wheels/tires. I wonder if 4.56 would be the enough to turn the heavy tires without the high rpms.