Do I need to upgrade anything for 37s on a daily driver?

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Maximus

JK Enthusiast
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Mar 3, 2020
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Wilmington, De
As some of you may have seen my posts, I just got back into a Wrangler after a long time away and already have the mod bug biting me. My TJ I had years ago had 33’s on it but now that’s just not cutting it for me personally. I have a 2015 2-door manual and want to run 37’s. I drive roughly 50 miles a day during the week, don’t plan on beating it off-road, and drive predominately on streets of course. In addition to a lift, would I REALLY need to upgrade anything for normal, easy-going everyday driving?
Thanks!
 
To run 37s daily, you'll ideally want a C load rated tire (if you can find one), a 4" lift (or more), stronger axle shafts (if you plan to off-road it), and I'd also highly recommend re-gearing it, as 37s isn't going to be great with stock gearing.
 
Chris said:
To run 37s daily, you'll ideally want a C load rated tire (if you can find one), a 4" lift (or more), stronger axle shafts (if you plan to off-road it), and I'd also highly recommend re-gearing it, as 37s isn't going to be great with stock gearing.
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Thanks Chris. Off-roading most likely will hardly ever happen so for now I won’t worry about the axle shafts. However as far as gearing goes, what would you suggest? Is it blatantly obvious I’m not very mechanically inclined? Lol

Thanks again,
Chris
 
You're definitely going to need a lift kit for 37's! We have 20+ years of experience lifting jeeps if you ever need help or have any questions about everything that's involved when lifting your vehicle, feel free to give us a call at (203) 691-8593
 
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On the gearing, you will need above a 4.56 gear to have performance that you need. The Clayton people can look into that for you. I run 35's and have 4.56 Eaton Electronic Lockers front and rear on my rig as I do tow an RV Travel Trailer.
 
Ballermaris said:
On the gearing, you will need above a 4.56 gear to have performance that you need. The Clayton people can look into that for you. I run 35's and have 4.56 Eaton Electronic Lockers front and rear on my rig as I do tow an RV Travel Trailer.
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Thanks for the advice on gearing 👍🏼
 
Maximus said:
Thanks Chris. Off-roading most likely will hardly ever happen so for now I won’t worry about the axle shafts. However as far as gearing goes, what would you suggest? Is it blatantly obvious I’m not very mechanically inclined? Lol

Thanks again,
Chris
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Is it an auto or a manual? If it's an auto I would go with 4.88 personally, and if it's a manual I would go with 4.56.

If you aren't wheeling it, the stock axle shafts will be fine. (y)
 
Chris said:
Is it an auto or a manual? If it's an auto I would go with 4.88 personally, and if it's a manual I would go with 4.56.

If you aren't wheeling it, the stock axle shafts will be fine. (y)
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Manual 👍🏼
As much as I would like to, honestly it will hardly, if ever, get wheeled so stock axles sound good
 
Maximus said:
Manual 👍🏼
As much as I would like to, honestly it will hardly, if ever, get wheeled so stock axles sound good
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Yep, 4.56 for your manual then for sure. 4.88 would be for autos only because it's geared slightly different. Of course those ratios are so close together that realistically you could go with either, but 4.56 will work great for you (y)
 
4" of lift is a bit excessive for a 37. On the street you can run 37"s with a 2.5" lift (flat fenders will clear them off road as well). 4" will definitely give you room but you'll sacrifice drivability on the street unnecessarily. The lower center of gravity you have the easier it will be to control. As far as the axles are concerned I'd gusset the inner C's and truss it regardless if it's a rubicon or not.
 
Willys14jk said:
4" of lift is a bit excessive for a 37. On the street you can run 37"s with a 2.5" lift (flat fenders will clear them off road as well). 4" will definitely give you room but you'll sacrifice drivability on the street unnecessarily. The lower center of gravity you have the easier it will be to control. As far as the axles are concerned I'd gusset the inner C's and truss it regardless if it's a rubicon or not.
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I think ideally I’m going 3 1/2” of lift
 
Maximus said:
I think ideally I’m going 3 1/2” of lift
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3.5 is the norm. But a buddy of mine runs 3.5 w/ 37"s and the difference in just 1 inch of lift was wild. If you go that high I'd recommend going with a long arm kit so your control arm angle isnt as extreme and slightly easier to adjust your caster angle.
 
Willys14jk said:
3.5 is the norm. But a buddy of mine runs 3.5 w/ 37"s and the difference in just 1 inch of lift was wild. If you go that high I'd recommend going with a long arm kit so your control arm angle isnt as extreme and slightly easier to adjust your caster angle.
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Good advice
 
Chris said:
To run 37s daily, you'll ideally want a C load rated tire (if you can find one), a 4" lift (or more), stronger axle shafts (if you plan to off-road it), and I'd also highly recommend re-gearing it, as 37s isn't going to be great with stock gearing.
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Question: knowing I won’t be off-roading hardly at all (if anything just easy trails) and will be driven almost always on the street....would I need to truss up front?
 
Maximus said:
Question: knowing I won’t be off-roading hardly at all (if anything just easy trails) and will be driven almost always on the street....would I need to truss up front?
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Nope, definitely not.

You wouldn't even need a truss off-road, unless you were just beating the piss out of it.
 
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If you plan to wheel it at all on 37's and want to keep the dana 30 up front I would definitely recommend a truss, inner C gussets, regear, and chromoly shafts. If it's just going to see asphalt you could probably do without the added strength but it will feel extremely sluggish without at least regearing.
 
Chris said:
Nope, definitely not.

You wouldn't even need a truss off-road, unless you were just beating the piss out of it.
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Ok that’s kind of what I thought as well. Kind I’d like my other post about shocks with reservoirs and if they’re necessary for the street....I feel like it’s just something of a “yeah I got that under there too” thing that’s not necessary but it’s there “just because”

Thanks again
 
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