Notices
JK Wheels and Tires For all questions and answers concerning Wheels and Tires for Jeep JKs.

35s or 37s - what's required

 
Old 03-31-2019, 03:36 PM
  #1  
JK Enthusiast
Thread Starter
 
snakeyes76's Avatar
 
Join Date: May 2011
Location: montreal, quebec
Posts: 316
Received 0 Likes on 0 Posts
Default 35s or 37s - what's required

so a couple of weeks ago i posted about thoughts on a lift
we (the wife) decided on the 3.5" metalcloak overland rocksport kit
i added the rear adjustable trackbar, rear coil retainers and rear adj arms (kit has front drop brackets)
now she's debating on tires
i'm leaning towards 35s (yokohama mt g0003, grabber x3s, deegan 38s, cooper stt pro)
she really wanted 37s but i advised against it as i believe it entails a lot more mods
i would prefer not to regear
i've run 35s on my 2012 rubi 2dr auto trans with just a superchips tune which helped return the stock acceleration but i think going to 37s would require more than that
it is a manual rubi (4.10s)
i'm thinking regearing and at the least C-gusset reinforcement if going to 37s
am i forgetting something?
i would rather keep stock fender flares as it lines up nicely with the AEV bumpers (have not seen flat fenders with those bumpers but i think it would look a little off)

thoughts/suggestions?
BTW- it's 99% a pavement princess but she also doesn't do much mileage..maybe 4000 miles a year

Last edited by snakeyes76; 03-31-2019 at 03:42 PM.
snakeyes76 is offline  
Old 03-31-2019, 04:19 PM
  #2  
JK Jedi Master
 
Join Date: Jan 2008
Location: Texas
Posts: 10,945
Likes: 0
Received 49 Likes on 48 Posts
Default

They both bring the same issues, they are just likely to be more pronounced and show up sooner with 37's than with 35's. I don't think I'd let that sway the opinion, if she wants 37's get em.

From a purely visual perspective, this is 3.5" MetalCloak coils and 37" STT Pro's with stock fenders (before I got around to chopping that set.) For me at least, these coils gave a good bit of height. I would want to drop to 2.5" coils with 35's...


)
nthinuf is offline  
The following users liked this post:
snakeyes76 (03-31-2019)
Old 03-31-2019, 05:36 PM
  #3  
JK Jedi
FJOTM Winner
 
resharp001's Avatar
 
Join Date: Jun 2013
Location: Willow Park, TX
Posts: 4,486
Received 251 Likes on 240 Posts
Default

Hey nthinuf, those coopers are relatively quiet right? IIRC they aren't super loud. I had a buddy asking about them today. He ended up picking Ridge Grapplers in the end. Seems like I hear nothing but good commentary about the Cooper SST though.

I had the original Yoko Geolanders as my first tire. For a MT tire on the pavement they were decent....not loud at all. I hate those MTs you hear coming all the way down the street. I think Yoko made a lot of improvements on that tire to the new one you mentioned. I have not seen/heard those in person, but based on previous model, and especially if not hardcore wheel aired way down to 10psi, I think the Yoko is at least worth consideration.
resharp001 is offline  
Old 03-31-2019, 05:44 PM
  #4  
JK Enthusiast
Thread Starter
 
snakeyes76's Avatar
 
Join Date: May 2011
Location: montreal, quebec
Posts: 316
Received 0 Likes on 0 Posts
Default

Originally Posted by resharp001 View Post
Hey nthinuf, those coopers are relatively quiet right? IIRC they aren't super loud. I had a buddy asking about them today. He ended up picking Ridge Grapplers in the end. Seems like I hear nothing but good commentary about the Cooper SST though.

I had the original Yoko Geolanders as my first tire. For a MT tire on the pavement they were decent....not loud at all. I hate those MTs you hear coming all the way down the street. I think Yoko made a lot of improvements on that tire to the new one you mentioned. I have not seen/heard those in person, but based on previous model, and especially if not hardcore wheel aired way down to 10psi, I think the Yoko is at least worth consideration.
It seems like the heaviest and truest to size are the Grabber X3s. The lightest and also smallest (in a 35) are the Cooper STT Pros but I have also heard nothing but great things about them.
I personally like the Yokos. Good balanced tire in either 35 or 37 regarding true to size and weight and the tread patters is nice and aggresive. Cooper STT Pros also have an awesome tread pattern
snakeyes76 is offline  
Old 03-31-2019, 05:54 PM
  #5  
JK Jedi Master
 
Join Date: Jan 2008
Location: Texas
Posts: 10,945
Likes: 0
Received 49 Likes on 48 Posts
Default

Originally Posted by resharp001 View Post
Hey nthinuf, those coopers are relatively quiet right? IIRC they aren't super loud.
Yep, very quiet compared to others I have run in the past. Around 10k or so they got a bit louder, kind of a more noticeable hum. But nowhere near the loud growl or warble you can hear coming toward you from blocks away. It's funny how different it is here in Austin than up in Colorado, every time I hear that growl coming toward me and expect to see a jeep on big mudders - it is invariably a full-size truck on tiny 30" tires.
nthinuf is offline  
Old 03-31-2019, 06:08 PM
  #6  
JK Enthusiast
Thread Starter
 
snakeyes76's Avatar
 
Join Date: May 2011
Location: montreal, quebec
Posts: 316
Received 0 Likes on 0 Posts
Default

Originally Posted by nthinuf View Post
Yep, very quiet compared to others I have run in the past. Around 10k or so they got a bit louder, kind of a more noticeable hum. But nowhere near the loud growl or warble you can hear coming toward you from blocks away. It's funny how different it is here in Austin than up in Colorado, every time I hear that growl coming toward me and expect to see a jeep on big mudders - it is invariably a full-size truck on tiny 30" tires.
that's really good to know.. the wife seems to like the Coopers the most and going to a 37 is only 6lbs heavier than a 35 yokohama. also the wheel gap in the pic above is how she envisioned it looking
if they made a 35x12.5x17 in the STT Pro i would possibly go with that because the 315/70/17 overall diameter is stated as 34.5 and i know all (or most) tires run smaller than advertised
all these decisions are a little overwhelming when trying to explain every detail to your better half and helping her understand why size, weight, etc would matter and how it affects acceleration, handling, fuel consumption, bla bla bla
snakeyes76 is offline  
Old 03-31-2019, 06:26 PM
  #7  
JK Jedi Master
 
Join Date: Jan 2008
Location: Texas
Posts: 10,945
Likes: 0
Received 49 Likes on 48 Posts
Default

If it helps any, here are the measurements from when I first put them on. I was actually expecting around 35.5" mounted and under load, so, bonus.

36.77" - Mfg spec.
36.60" - actual measured unmounted height
36.00" - front tire, 17x9 rim @28 psi
nthinuf is offline  
Old 04-01-2019, 05:28 AM
  #8  
Super Moderator
 
BoraBora's Avatar
 
Join Date: Mar 2015
Location: McLean, VA
Posts: 601
Received 27 Likes on 26 Posts
Default

Here's a great thread that breaks down everything you really "need" for 37's:

https://www.jk-forum.com/forums/modi...d-help-349200/
BoraBora is offline  
Old 04-01-2019, 06:45 AM
  #9  
JK Newbie
 
Sltimmins's Avatar
 
Join Date: Jan 2017
Location: NOVA
Posts: 51
Likes: 0
Received 1 Like on 1 Post
Default

Originally Posted by BoraBora View Post
Here's a great thread that breaks down everything you really "need" for 37's:

https://www.jk-forum.com/forums/modi...d-help-349200/
Taken directly from resharps post:

"So, with 37s, you need to think about these things:
  • You’ll most likely have to regear, which means adding a programmer as well if you don’t already have one
    • This could lead you down the whole “do I want to add lockers or not at the same time
      • Which will lead you down the rabbit hole of WHICH lockers
        • Which could lead you down the path or replacing axle shafts to match new locker spline count
        • Which could lead you down the path of is putting money in to a D30 worthwhile
  • You’ll probably need new rear axle shafts as the factory flanges tend to bend easily with 37s (even if you don’t off road)
  • 3.5” BS is most appropriate for 37s, and you’re not going to find many non-beadlock options with that BS
    • You can indeed run spacers…..those can get to be a drag if you do much work on your jeep IMO
      • If you have spacers, many tire shops won’t touch your vehicle. This depends on location usually.
      • If you have beadlocks, many shops won’t touch your vehicle. This depends on location usually.
  • You’d better factor in some expensive ball joints, Rare Parts would be your best option
    • Factory BJs ain’t gonna hold up, and if you wheel, odds of TF, Synergy, Alloy….they’re all a crapshoot
    • I cannot recommend DT at all. You can search up my thread on rebuilding those….not worthwhile.
  • Plan on new drive shaft if lifting 3”+, or at the VERY lease rebuilding a factory shaft using the TF high angle rzeppa.
    • Boot at the TC-side CV joint will rip, spew all the grease, and the joint will dry out leading to early failure
  • With 37s and 3”+ lift, you really need to have a full set of control arms IMO.
    • Especially in the rear, you’re gonna want the ability to move the axle back again as the tire really creeps forward in the wheel well
      • Even with significant trimming of the pinch seam, which you’re gonna have to do, you’ll probably want more clearance
        • Pushing the axle back will probably require you to relocate or remove your rear sway bar back an inch
          • Relocating your rear sway bar will probably force you to address the factory muffler
            • If you relocate the muffler to between the axles, you’ll need to address evap canister
  • If you wheel, you’ll probably need to address your exhaust crossover up front.
    • Exhaust spacers are a bandaid IMO
  • You may likely want to upgrade your brakes, and will be deciding between big brake kits and big rotor kits
  • You’ll address every steering and suspension component as already mentioned. TR, DL, TB, control arms, springs, shocks, bump stops, sway links, brake lines, etc.
  • Probably want to add C gussets at the very least if you don't have em already"
He pretty much hits every point "needed" to run 37s.
Sltimmins is offline  
Old 04-01-2019, 07:27 AM
  #10  
JK Jedi
FJOTM Winner
 
resharp001's Avatar
 
Join Date: Jun 2013
Location: Willow Park, TX
Posts: 4,486
Received 251 Likes on 240 Posts
Default

Y, thought hit the OP with that link on previous thread when they were narrowing down thoughts on lift, but maybe not.

The real beating isn't necessarily that 37s entail a bit more, it's just that each change tends to beget another change, and there's no clean break.....but that is kind of the same with modifying in general. For an example, adding 37s to a 3.5" lift was the tipping point of needing to re-position the axles and re-extend the wheel base. No problem, I was willing to pony up for a complete set of quality adjustable control arms. Well, moved the rear axle back which was nice, but then the sway bar links caused interference....no problem, move rear sway bar back, cept that interferes with the exhaust, no problem, replace the exhaust. What's that banging noise going over bumps? Oh, it's the rear TB bolt hitting my rear bump stops....need to stagger those rear bumps now. It's that kinda thing that gets aggravating.

I think those lists that myself and Bora Bora put in that thread really addressed what you need to at least think about to run 37s. If just a pavement princess, probably can get by on less, but at least be aware of the bullet points.
resharp001 is offline  

Quick Reply: 35s or 37s - what's required


Contact Us - About Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

 
  • Ask a Question
    Get answers from community experts
Question Title:
Description:
Your question will be posted in: