3.5" backspacing - Jeep Wrangler Forum
Jeep Wrangler Forum

Go Back   Jeep Wrangler Forum > JK Jeep Wrangler Forum > JK Tech Forum

Join Wrangler Forum Today


Like Tree7Likes
  • 1 Post By Blue Baby Sound
  • 1 Post By Wandell
  • 2 Post By stitch1
  • 1 Post By KrawlOff-Road.com
  • 2 Post By Discount Tire
Reply
 
Thread Tools

Please support our sponsors and let them know you heard about them on WranglerForum.com
Old 09-25-2018, 01:20 PM
Thread Starter
  #1
Jeeper
 
mechfl's Avatar
 
Join Date: Aug 2015
Location: SWFL
Posts: 123
3.5" backspacing

So I read some threads here that said 3.5" wheel backspacing is not something you want to run on a daily driver...why? Is it just because the stock components are weak, is it dangerous? This phase I'm upgrading front to Rockjock 44, re-gearing back, elockers and moving up to 37" tires on my 15 JKU. I currently have 4.7" backspacing and 33" tires, I was rubbing my aluminum tie rod at full lock on the rim, but we were able to get it centered so it's JUST clear...like 1/8". (The wheels I'm looking at are the Dirty Dog DT-1 w/-38 offset) Thanks for sharing all your knowledge!

mechfl is offline   Quote
Old 09-25-2018, 02:13 PM   #2
Wrangler Forum Crew

5-Year WF Supporting Member
WF Lifetime Member
::WF Moderator::
 
Blue Baby Sound's Avatar
 
Join Date: Jan 2014
Location: Glenpool, OK (Tulsa)
Posts: 15,181
I would suggest to google scrub radius and study up on it. I'm not an expert by any means, but I understand more after reading up on it.

Here's a thread on the forum to get you started: https://www.wranglerforum.com/f274/s...us-684450.html

To answer your question, 3.5" BS on a 12.5" wide 37 is about right. Might work for a 13.5" too. I run 3.75" on the wifes with a 12.5" wide 37.
mechfl likes this.

__________________
HERS-2018 JK- Gobi- (WOOKIEE) Build Thread
HIS- 2014 JKUR- Copperhead Pearl (BRUTUS) Build Thread
Retired 2016 JKWW- Firecracker Red (MAXIMUS)
Retired 2013 JKUS- White- (THOR)
Blue Baby Sound is offline   Quote
Old 09-25-2018, 04:07 PM   #3
Jeeper
 
Wandell's Avatar
 
Join Date: May 2011
Posts: 1,371
With 35's on 9 inch wide wheels with 4.5 inches of BS, I had some rubbing on the control arms at full steering lock. I ran across a deal on some 1.5 inch RC wheel spacers and installed them. So that effectively gives me a 9 inch wheel with 3 inches of backspacing. No more rubbing and I like the slightly more aggressive stance.
mechfl likes this.
__________________
2011 JKU, 3.8v6, automatic, 2.5 inch lift, 35 inch Nitto Trail Grapplers on 17x9 Eagle Alloy 197 wheels
Wandell is offline   Quote
Sponsored Links
Advertisement
 
Old 09-26-2018, 01:20 PM   #4
Jeeper
 
stitch1's Avatar
 
Join Date: Feb 2016
Posts: 565
I run 3.5" back spacing with 37" tires. So far I have nothing but good things to say about it.
HD_Rider and mechfl like this.
stitch1 is offline   Quote
Old 09-27-2018, 10:08 AM   #5
Sponsoring Vendor
 
KrawlOff-Road.com's Avatar
 
Join Date: Sep 2011
Location: Anderson, SC
Posts: 4,388
No issues with a 3.5"BS on a stock axle nor the ProRock 44. I have been running 3.5"BS on my PR44 with a 40x1350x17 for almost 6 years. No issues.

-Jason
__________________
KrawlOff-Road.com:
Facebook
Email
Phone: 864-437-8029
Forum Discount: KORWRANGLERFORUM
KrawlOff-Road.com is offline   Quote
Old 09-27-2018, 10:31 AM   #6
Wrangler Forum Crew

5-Year WF Supporting Member
WF Lifetime Member
::WF Moderator::
 
Blue Baby Sound's Avatar
 
Join Date: Jan 2014
Location: Glenpool, OK (Tulsa)
Posts: 15,181
Quote:
Originally Posted by KrawlOff-Road.com View Post
No issues with a 3.5"BS on a stock axle nor the ProRock 44. I have been running 3.5"BS on my PR44 with a 40x1350x17 for almost 6 years. No issues.

-Jason
Hey Jason!
I just added 40x13.5x17 on my '14 stock width axle and 2.5" BS, and I'm still rubbing at full lock. I've added washers to limit the steering but I was curious where you're at on yours and 3.5" BS.

Thanks!
Jeff
__________________
HERS-2018 JK- Gobi- (WOOKIEE) Build Thread
HIS- 2014 JKUR- Copperhead Pearl (BRUTUS) Build Thread
Retired 2016 JKWW- Firecracker Red (MAXIMUS)
Retired 2013 JKUS- White- (THOR)
Blue Baby Sound is offline   Quote
Old 09-27-2018, 11:28 AM   #7
Sponsoring Vendor
 
KrawlOff-Road.com's Avatar
 
Join Date: Sep 2011
Location: Anderson, SC
Posts: 4,388
Quote:
Originally Posted by Blue Baby Sound View Post
Hey Jason!
I just added 40x13.5x17 on my '14 stock width axle and 2.5" BS, and I'm still rubbing and full lock. I've added washers to limit the steering but I was curious where you're at on yours and 3.5" BS.

Thanks!
Jeff
Jeff,

Mine was rubbing on the frame. LOL Never had hurt the tire though so I just use it as the steering stop.

-Jason
Blue Baby Sound likes this.
__________________
KrawlOff-Road.com:
Facebook
Email
Phone: 864-437-8029
Forum Discount: KORWRANGLERFORUM
KrawlOff-Road.com is offline   Quote
Old 09-27-2018, 11:32 AM   #8
Supporting Member

5-Year WF Supporting Member
 
FootSoldier's Avatar
 
Join Date: Aug 2014
Location: Scottsdale, Arizona
Posts: 797
I just did a bunch of work to run Falcon 3.3 shocks on my Jeep and the net result was I needed to add a set of 1.5" spacers to get clearance everywhere.

The basic setup is AEV Saltas with 5.2" back spacing, 1.5" spacers, 35" STT PROs and I've been worried about the effects to the scrub radius number since I finished the work.

Haven't had much chance to actually drive it yet, but it drove so well without the spacers before, I'm worried the mods may not have been a good choice?

Does anyone know of an online calculator where you can run the numbers and see what the effect of changes like this are?
__________________
2016 JKR Mojave Sand--The Harbaugh Wolverine; RK 2.5 X-Factor, Falcon 3.3s, PoisonSpyder flares/liners, sliders, and cage, Revolution 4.88s and USA axles, Artec armored housings and HD X-member, Dynatrac BJs, Rock Hard full skids, ARB HD Diff covers, Off Camber Fab bumpers, Teraflex HD tire carrier, Warn Zeon 8S, AEV Saltas, 35" STT PROs, SPod/LED lights, Mopar/Dynatrac BBK, RCV axles, T6 Alum 1 ton TR/DL, PowerTank.

https://www.wranglerforum.com/f314/f...d-1666418.html
FootSoldier is offline   Quote
Old 10-02-2018, 12:34 PM   #9
 
Discount Tire's Avatar
 
Join Date: Oct 2010
Location: USA
Posts: 3,010
As mentioned, 3.5-inches to 3.75-inches is ideal for 37's.

The lower backspace in "theory" may create more leverage on components but at to what degree it creates premature failure is difficult to determine. As you've read, a lot of members run this on factory axles without issue.

Let us know if we can help you with your next combo
***
mechfl and stitch1 like this.
__________________
Low Prices! More Choices! Trusted Experts!
At The Store: discounttire.com
To Your Door: discounttiredirect.com
Discount Tire is offline   Quote
Old 10-02-2018, 02:26 PM   #10
Jeeper
 
monte417's Avatar
 
Join Date: Oct 2013
Location: East Meadow, NY
Posts: 666
Quote:
Originally Posted by Discount Tire View Post
As mentioned, 3.5-inches to 3.75-inches is ideal for 37's.

The lower backspace in "theory" may create more leverage on components but at to what degree it creates premature failure is difficult to determine. As you've read, a lot of members run this on factory axles without issue.

Let us know if we can help you with your next combo [IMG class=inlineimg]https://www.wranglerforum.com/images/smilies/thumb.gif[/IMG]
***
Do you guys carry those dirty life wheels? Didn’t see them in your site and had a few questions
__________________
2012 Black Sport * Manual * JKS 2.5 Coils * Rancho 9000s * Rubi Axles * 37 Trail Grapplers * Artec Armor * Procomps * JKS Front Tracbar * JKS Disconnects * Superchips * Dynomax * KnN * KCs * Synergy Arms* Synergy Steering * Ten Factory Axle Shafts * EVO C Gussets * Hydro Assist * TrekArmor * Synergy Rear Shock Relocation Brackets
monte417 is offline   Quote
Old 10-04-2018, 03:45 PM   #11
 
Discount Tire's Avatar
 
Join Date: Oct 2010
Location: USA
Posts: 3,010
Quote:
Originally Posted by monte417 View Post
Do you guys carry those dirty life wheels? Didnít see them in your site and had a few questions
Our apologies for the late reply!

Discount Tire Direct does not stock Dirty Life wheels, however, they can order any of their wheels

Shoot us PM with any questions you have and we'll be happy to answer them!
__________________
Low Prices! More Choices! Trusted Experts!
At The Store: discounttire.com
To Your Door: discounttiredirect.com
Discount Tire is offline   Quote
Old 10-05-2018, 12:19 AM   #12
Jeeper
 
TRBOKEV's Avatar
 
Join Date: May 2014
Location: Phillips Ranch
Posts: 978
I wheel 37ís with 4.5 backspaced wheels and have zero rub.







Click image for larger version

Name:	F44D8C82-9B6B-4E8A-84AA-18B17772F33E.jpg
Views:	86
Size:	242.9 KB
ID:	4098763

TRBOKEV is online now   Quote
Reply

Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off






All times are GMT -5. The time now is 11:43 PM.


Powered by vBulletin® Version 3.8.8
Copyright ©2000 - 2020, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.1
User Alert System provided by Advanced User Tagging v3.1.0 (Pro) - vBulletin Mods & Addons Copyright © 2020 DragonByte Technologies Ltd.
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2020 DragonByte Technologies Ltd.

Jeepģ, Wrangler, Liberty, Wagoneer, Cherokee, Gladiator, Mopar and Grand Cherokee are copyrighted and trademarked to FCA US LLC.
Wranglerforum.com is not in any way associated with FCA US LLC.