skibovr6

Hello all. I have been busy working on the "Jurassic" JK. I am almost done with my long list. The Jeep is a 2011 3.8 6spd with 3.73 gears. Its lifted with an AEV 3.5 and I run 35 MTRs. The jeep and trailer weigh about 6400lbs. I have a gobi rack, warn winch, ACE stubby front and ORFab rear bumper. I am looking for the best gear ratio for this Jeep. I have seen the gear ratio spec sheets but they dont account for these things. The Jeep was just fine living in Virginia. I recently moved to Oregon and the hills are killing me, especially with the trailer and tent. Just wanted to get some real opinions on gears. I have been thinking about maybe 37s way down the road but most likely sticking with 35s. Should I go 4.88 or 5.13s? Any info would be great. I have looked and searched everywhere but cant find datas with the weight and trailer.

JKphotoshoot

If it's a auto 5:38's. I am in the same situation. Just moved from Mississippi to utah. Even with 5:38's and 37's it sucks on these mtns!
I ran 5:38's in my Dana 30 with 37 mud grapplers and they held up. Just didn't get to crazy with them.
Richmond gear made the gears but they are hard to come by now. 5:13 without a doubt otherwise.

Edit. Missed the 6 speed, but if you plan on 37's I would probably still do 5:13.
Especially pulling a trailer and all that weight. My rigs 5700 unloaded.

skibovr6

Yes its a Man. 6spd. I was worried that the revs would be to high with the 5.13 and 35s

TheDirtman

IF you like driving fast on the interstate I would look at 4.88 if you are no speed demon and drive 55-60 the 5.13 would be a good choice towing a trailer in the hills.

Sahara Lee

With the 6-speed, 4.88 should be enough with 35s. 6th gear trans gear ratio is not nearly as high as auto OD.

37s might be another story. I can't say. Never had 37s. But many here who have done 37s with the 1 gallon engine and manual (I prefer British units).

BTW - My beast is not light on her feet either.

ronjenx

But, 3.6L and 3.8L don't equal 1 gallon in the UK.

Mark Doiron

Yep. Let me give this some numbers: At 70 MPH with 4.88s you'll be turning 3,000 RPMs. Try driving around in a lower gear at 70 MPH and 3,000 RPMs and see how comfortable you are with that. I have a friend who won't cruise above 70 MPH because he is not happy with it. But, he has 5.13s. And, of course, 5.13s are weaker, especially in a D30 (you don't have a Rubi, right?), though for expedition travel that is less problematic than for a full-time rock crawler. But, bottom line, you're still going to find yourself gasping to get to the tops of hills, even with 5.13s.

skibovr6

It's a non rubicon with a 30 and 44. We are in Bend Oregon and have a ton of hills and passes. In town I rarely maybe once a month will get above 50mph. I take it off road but only on trails no crawling. More concerned with power and towing for the hills than highway

Mark Doiron

4.88s or 5.13s will help. Just don't expect to hold sixth gear on those grades. But it will be better.

TeraFlex

With the amount of weight you have plus the trailer and hills, I would suggest 5:13's. Love that trailer that you have.