Let's talk tire pressure - JeepForum.com
Search  
Sign Up   Today's Posts
User: Pass: Remember?
Advertise Here
Jeep Home Jeep Forum Jeep Classifieds Jeep Registry JeepSpace Jeep Reviews Jeep Gallery Jeep Clubs Jeep Groups Jeep Videos Jeep Events Jeep Articles
Go Back JeepForum.com > Models > Jeep Wrangler Forums > YJ Wrangler Technical Forum > Let's talk tire pressure

Dan's Old as Dirt Birthday Sale!GEARSHADE Pocket Tops in stock and available at ROCKRIDGE Yukon Ultimate 35 axle kit for c/clip axles with Yukon Zip

Reply
Unread 07-20-2013, 09:20 PM   #1
rambo3489
Registered User
1989 YJ Wrangler 
 
Join Date: Feb 2011
Location: Albuquerque, New Mexico
Posts: 1,633
Let's talk tire pressure

Alright guys,

Long story short I caused a lot of trouble saying I ran my MTR/Ks at 14 psi. I just got them and that's what the chalk test said to run them at. Gave me full tread contact across the tires. I was then informed the chalk test is not the best tool to use with big tires on proportionally small wheels. OK. So I ran my tires at the PSI range that was suggested to me. (20-24 psi) This picture was with 20 PSI.

Well I just got back from a little light wheeling got some mud on the tires and made an interesting observation. The tires are only contacting on the center as I feared form the start. See:



__________________
89 YJ.. My first jeep and I won't let it go. ▀||||▀

Current Project: None... I disgust myself.

[URL="http://www.jeepforum.com/forum/f22/my-yj-build-adventures-thread-1356941/"][SIZE="3"][B]BUILDING THE YJ MY WAY[/B][/SIZE][/URL]
rambo3489 is offline   Reply With Quote
Unread 07-20-2013, 09:24 PM   #2
Anticanman
Follow me
1994 YJ Wrangler 
 
Join Date: Aug 2009
Location: Ripon, California
Posts: 19,223
That looks ok to me. The way the lugs are shaped, its not supposed to have full tread contact on the pavement all the time.
__________________
Luck Favours The Prepared
[SIGPIC][/SIGPIC]
Anticanman is offline   Reply With Quote
Unread 07-20-2013, 09:35 PM   #3
dillonjm
30mm @ 70/sec
 
dillonjm's Avatar
2003 TJ Wrangler 
 
Join Date: Jun 2003
Location: Warrensburg, MO
Posts: 3,908
Quote:
Originally Posted by Anticanman View Post
That looks ok to me. The way the lugs are shaped, its not supposed to have full tread contact on the pavement all the time.
This.

Looks about right to me.
__________________
03 Rubi on 35's (Weekend Toy)

11 Ram 2500 - 6.7 Cummins (DD/Tow Rig)

05 Liberty Limited (Wife's): Minor mods, OME/JBA Suspension, 245 70/17 Duratracs
dillonjm is offline   Reply With Quote
Unread 07-20-2013, 09:40 PM   #4
rambo3489
Registered User
1989 YJ Wrangler 
 
Join Date: Feb 2011
Location: Albuquerque, New Mexico
Posts: 1,633
No kidding?! Alright thanks guys
__________________
89 YJ.. My first jeep and I won't let it go. ▀||||▀

Current Project: None... I disgust myself.

[URL="http://www.jeepforum.com/forum/f22/my-yj-build-adventures-thread-1356941/"][SIZE="3"][B]BUILDING THE YJ MY WAY[/B][/SIZE][/URL]
rambo3489 is offline   Reply With Quote
Unread 07-20-2013, 09:45 PM   #5
dillonjm
30mm @ 70/sec
 
dillonjm's Avatar
2003 TJ Wrangler 
 
Join Date: Jun 2003
Location: Warrensburg, MO
Posts: 3,908
Its going to even out eventually too. But that is about what i run mine at, new(ish).

Granted my WJ needs about 28-30lbs of pressure vs 20. Apples to oranges though, considering tire size, weight, tire load rating, etc.
__________________
03 Rubi on 35's (Weekend Toy)

11 Ram 2500 - 6.7 Cummins (DD/Tow Rig)

05 Liberty Limited (Wife's): Minor mods, OME/JBA Suspension, 245 70/17 Duratracs
dillonjm is offline   Reply With Quote
Unread 07-21-2013, 06:13 AM   #6
UltimatE
Resident Audio Guru
 
UltimatE's Avatar
1994 YJ Wrangler 
 
Join Date: Sep 2004
Location: Worcester, Mass
Posts: 7,035
This is how my chalk test ended up. The outside of the tread is also rounded on my KM2s, so there is still some chalk left on the outsides. Nothing to worry about.

__________________
-Matt

White '94 YJ Sport
Black '98 ZJ Laredo - 45x60 Surco Rack - 2" Budget Boost, Addco Front Swaybar

Project (s)Low - A build log.
UltimatE is offline   Reply With Quote
Unread 08-31-2013, 08:20 AM   #7
tom_sprecher
Registered User
1991 YJ Wrangler 
 
Join Date: Dec 2012
Location: Marietta, GA
Posts: 416
I just installed 33 x 12.5 x 15 KM2's. What is a good starting pressure to do the chalk test?
__________________
Tom
tom_sprecher is offline   Reply With Quote
Unread 08-31-2013, 08:43 AM   #8
RockWoRM
Don't Fear the Jeeper
 
RockWoRM's Avatar
1992 YJ Wrangler 
 
Join Date: Mar 2006
Location: Fresno, Ca.
Posts: 8,235
I think it's pretty safe to say forget the chalk test and just run them in the low/mid twenties... 22-24 and you'll be fine. YJ's are not that heavy and when running meats in the 33-35 flavor on your average 8" rim, that is about the right psi. Off road, drop 'em down to whatever you like. .o2



WRM
__________________
'92 YJ, 4.0, 5sp, 8.8 w/ 4.56's locked F&R, Teralow 4-1, HD SYE, BDS 5" SUA lifted on 35 MTR's. PSE front trail cage kit, 1ton TRE flip, 1"shackles, 1"BL, 1" MM. <><

Quote:
Originally Posted by 80 CHOPPER View Post
Knowledge is a tool, without knowledge, you are just a tool.
RockWoRM is online now   Reply With Quote
Unread 08-31-2013, 09:51 AM   #9
Tom95YJ
[] Eye'd Jeep Connoisseur
 
Tom95YJ's Avatar
1999 XJ Cherokee 
 
Join Date: Sep 2004
Location: Salt Lake City, Utah
Posts: 8,231
You guys dont wheel enough, Or your not wheeling properly your lugs are still in great shape, Mine are all cut and chunked from wheeling
__________________
'89 YJ The Smurf Build Thread
'99 XJ Black Betty Build Thread
Tom95YJ is offline   Reply With Quote
Unread 08-31-2013, 12:26 PM   #10
rambo3489
Registered User
1989 YJ Wrangler 
 
Join Date: Feb 2011
Location: Albuquerque, New Mexico
Posts: 1,633
Quote:
Originally Posted by Tom95YJ View Post
You guys dont wheel enough, Or your not wheeling properly your lugs are still in great shape, Mine are all cut and chunked from wheeling
... My picture was taken a week after I completed a frame off build, with a tranny without third gear. Cut me some slack.
__________________
89 YJ.. My first jeep and I won't let it go. ▀||||▀

Current Project: None... I disgust myself.

[URL="http://www.jeepforum.com/forum/f22/my-yj-build-adventures-thread-1356941/"][SIZE="3"][B]BUILDING THE YJ MY WAY[/B][/SIZE][/URL]
rambo3489 is offline   Reply With Quote




Jeep, Wrangler, Cherokee, Grand Cherokee, and other models are copyrighted and trademarked to Jeep/Chrysler Corporation. JeepForum.com is not in any way associated with Jeep or the Chrysler Corp.