2008 JKU Regearing help: 5.38v5.86 on 37"s
#1
JK Newbie
Thread Starter
2008 JKU Regearing help: 5.38v5.86 on 37"s
I'm new to owning a Wrangler and know nothing about axles or gearing. I have a 4D Rubicon with auto transmission, stock axles (Dana 44 I believe), and stock 4.10 gearing. I am currently running 37" tires (no plans of ever going larger, but could possibly drop to a 35" in the future). Based on countless searches through the forums it seems I'd benefit from regarding down to either a 5.38 or 5.86.
Can the Dana 44 handle 5.38 or 5.86? Are there benefits or downsides to either of these? Which would you recommend and why? I really appreciate any help the community can offer. I'm hoping your experience can point me in the right direction.
Can the Dana 44 handle 5.38 or 5.86? Are there benefits or downsides to either of these? Which would you recommend and why? I really appreciate any help the community can offer. I'm hoping your experience can point me in the right direction.
#2
Super Moderator
Welcome to JKF.. Nice Ride.. Curious; what is your intended or planned use for your Rubi? 4.10s w/35s is what I run with a 6spd .. upgraded from 3.73s when went to 35s. 70 mph is at the 2200 rpm level on the highway.. IMHO- Unless you are climbing mountains you won't need the 5's and you will suffer a loss in MPG. If you plan on 40s then 5's would be feasible.
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#5
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With my 3.8 Auto, I am running 5.38's and 37's (with a 'measured' height of 36"), which has it just over 2400 rpm's at 70mph. Maybe a bit higher than some other folks would prefer, but works just fine for me.
#6
JK Newbie
Thread Starter
Welcome to JKF.. Nice Ride.. Curious; what is your intended or planned use for your Rubi? 4.10s w/35s is what I run with a 6spd .. upgraded from 3.73s when went to 35s. 70 mph is at the 2200 rpm level on the highway.. IMHO- Unless you are climbing mountains you won't need the 5's and you will suffer a loss in MPG. If you plan on 40s then 5's would be feasible.
#7
JK Newbie
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When you went to 5.38s did you notice a significant change in the feel? Mine is pretty sluggish currently. Seems quite a few are recommending 5.13's. Is there a reason you went with 5.38's? Based on your response above, I'm leaning towards 5.38. Thanks
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#8
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I was already running 5.13's and 35's, the bump to 5.38 and 37's came as part of an axle swap. But as far as a 'significant change in feel' goes, I think a lot of it depends on your own personal opinion/perception. Some folks go into a gear change believing it will be instant V-8 power - instead of just bringing the rpm's back up to a more usable level. But just looking at the numbers, there's only like a 110 rpm difference between the two ratios at freeway speeds, you'll be good either way you go.
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