Gearing options - Pirate4x4.Com : 4x4 and Off-Road Forum
 
Pirate4x4.Com : 4x4 and Off-Road Forum  

Go Back   Pirate4x4.Com : 4x4 and Off-Road Forum > Brand Specific Tech > Jeep - Non Hardcore
Notices

Reply
 
Share Thread Tools Display Modes
Old 03-01-2011, 04:55 PM   #1 (permalink)
Registered User
 
Join Date: Mar 2009
Member # 131296
Location: maple ridge,bc,canada
Posts: 50
Gearing options

Sorry if I posted this in the wrong section but I don't know where I should put it, feel free to move it if it's not in the right spot,

Anyway,

I'm building my diffs right now, well starting to... And I'm gonna be ordering my gears, I'm not too sure what I should be running for gears so I don't kill my motor but can still do 80-100km/hr on the highway,

What I'm running right now is

4.0L,AW4,np231 with teraflex 4.1 kit, hpD60 front and shaved,disk braked 14 bolt rear,

Tire size, I was thinking 40" tires,


I have a gear calculator on my phone and was thinking I should run 4.88 gears or 5.13,

What I'm worries about with 4.88's is being under powered, and what I'm also worried about is my rpms being too high on the highway with 5.13's anyone shine some light on this for me before I go and buy the wrong gears for my jeep?


Thank you
Nick
__________________
81 cj-5 frame, 76 cj-5 body, put together on 35" krawlers, 360v8,np435,d300 twin sticked

Last edited by whitetrashxj; 03-01-2011 at 05:18 PM.
whitetrashxj is offline   Reply With Quote
Old 03-01-2011, 05:39 PM   #2 (permalink)
Registered User
 
Join Date: Mar 2007
Member # 88919
Posts: 757
There's more to it than highway rpm's. It's highway load. 1 tons and 40+ tires weight a lot more. You NEED to turn those extra revs to keep the engine happy so you're not sucking down gas. 5.13's all the way, especially with the 4.0L. At 100kmh you're only going to be turning 1870 rpm's and that's hardly chugging along on the highway with 5.13's. Expect to downshift any time you hit a slight incline.

Make sure to install a great transmission cooler.
__________________
[COLOR="Lime"][I]At 1300rpm's would you rather have 10 extra hp or 10 extra lb-ft of torque?[/I][/COLOR]
Rinkrat456 is offline   Reply With Quote
Sponsored Links
Old 03-01-2011, 06:49 PM   #3 (permalink)
Registered User
 
POS YJ's Avatar
 
Join Date: Jan 2010
Member # 152085
Posts: 95
You WILL NOT be happy with 4.88's!! Go 5.13's, if not deeper. The 4.0 will run fine at 3,000rpm on the freeway if that's what you're worried about.
POS YJ is offline   Reply With Quote
Old 03-01-2011, 09:52 PM   #4 (permalink)
Registered User
 
Join Date: Aug 2010
Member # 166616
Location: Victorville, Ca
Posts: 281
40's? I say 5.38's. That thing is gonna be a pig.
Justdhutch is offline   Reply With Quote
Old 03-01-2011, 10:36 PM   #5 (permalink)
Rock God
 
Ho Shorts's Avatar
 
Join Date: Feb 2008
Member # 109328
Location: Maryville, TN
Posts: 1,675
I ran 4.88's with 38" on my XJ and it was on the borderline of being geared too high. 40's DEFINATELY go 5.13 if not 5.38
Ho Shorts is offline   Reply With Quote
Old 03-02-2011, 07:49 AM   #6 (permalink)
Registered User
 
Join Date: Aug 2008
Member # 118546
Location: NORWOOD, (BHAM) ALABAMA
Posts: 710
My vote is 5.38's
james@bluetorchfab is offline   Reply With Quote
Old 03-02-2011, 03:42 PM   #7 (permalink)
Registered User
 
Join Date: Feb 2008
Member # 108872
Location: Bennington, NE
Posts: 810
Send a message via AIM to MonsterSeven Send a message via Yahoo to MonsterSeven
if you have come this far, what makes you think you are going to stop at 40s? do it once, and do it right, the first time. 5.86s.
__________________
98 RHD TJ: 4.0L/AX-15/NP231, J54/S88, 37s, 57:1.
85 CJ-7: GM350/NV4500/D300, SOA, LP44/9" 110:1.
MonsterSeven is offline   Reply With Quote
Old 03-02-2011, 03:59 PM   #8 (permalink)
Registered User
 
Join Date: Aug 2010
Member # 166616
Location: Victorville, Ca
Posts: 281
Quote:
Originally Posted by MonsterSeven View Post
if you have come this far, what makes you think you are going to stop at 40s? do it once, and do it right, the first time. 5.86s.
He can't. 5.38 is as big as they go for the 14b.

Atleast I couldn't find any bigger. If they make 5.86's now I'm gonna be pissed because I just finished my install of 5.38's.
Justdhutch is offline   Reply With Quote
Old 03-02-2011, 04:03 PM   #9 (permalink)
Registered User
 
Join Date: Feb 2008
Member # 108872
Location: Bennington, NE
Posts: 810
Send a message via AIM to MonsterSeven Send a message via Yahoo to MonsterSeven
Quote:
Originally Posted by Justdhutch View Post
He can't. 5.38 is as big as they go for the 14b.

Atleast I couldn't find any bigger. If they make 5.86's now I'm gonna be pissed because I just finished my install of 5.38's.
time to find a different rear axle then.

in that case, 5.38s.
__________________
98 RHD TJ: 4.0L/AX-15/NP231, J54/S88, 37s, 57:1.
85 CJ-7: GM350/NV4500/D300, SOA, LP44/9" 110:1.

Last edited by MonsterSeven; 03-02-2011 at 04:04 PM.
MonsterSeven is offline   Reply With Quote
Old 03-02-2011, 04:21 PM   #10 (permalink)
Registered User
 
Join Date: Aug 2010
Member # 166616
Location: Victorville, Ca
Posts: 281
Quote:
Originally Posted by MonsterSeven View Post
time to find a different rear axle then.

in that case, 5.38s.
If you want a cheap, very strong axle, with disc brakes, you can't go wrong with a 14b. I'm into mine for under $500

14b -$50
5.38's -$150
Disc brake swap -$240 (and I could've went cheaper but got all new parts)
Justdhutch is offline   Reply With Quote
Old 03-02-2011, 04:29 PM   #11 (permalink)
New Beginnings
 
jpfrk2001's Avatar
 
Join Date: Sep 2007
Member # 99513
Location: On the move
Posts: 4,230
I have the EXACT drivetrain combo and tire size on my YJ. Go 5.38's Thats what I run

2800 RPM and Im turning around 75 on the Hwy no problem
__________________
Swapping Front ends:
http://www.pirate4x4.com/forum/gener...ront-ends.html
Motorcycle stuff.

NEW BEGINNINGS:
/forum/general-4x4-discussion/971511-jealle-o-cigano.html
jpfrk2001 is offline   Reply With Quote
Reply

Thread Tools
Display Modes

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 On
Pingbacks are On
Refbacks are On



All times are GMT -7. The time now is 08:46 AM.


Powered by vBulletin® Version 3.8.6
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Search Engine Optimization by vBSEO 3.6.0 ©2011, Crawlability, Inc.