Gear Ratio Change? - Jeep Wrangler Forum
Jeep Wrangler Forum

Go Back   Jeep Wrangler Forum > YJ Jeep Wrangler Forum > YJ General Discussion Forum

Join Wrangler Forum Today


Reply
 
Thread Tools

Please support our sponsors and let them know you heard about them on WranglerForum.com
Old 01-13-2014, 01:09 AM   #1
Jeeper
 
YJGRIZZ90's Avatar
 
Join Date: Jan 2014
Location: California
Posts: 34
Gear Ratio Change?

I've got a 1990 Wrangler with the 4.2L I6 and 5-speed maualt tranny. I'm planning on doing an engine swap to a vortec 350 V8 with a T400 tranny. Should I change my gear ratio? If so, to what?

YJGRIZZ90 is offline   Quote Quick Reply
Old 01-13-2014, 07:23 AM   #2
Jeeper
 
Join Date: Feb 2013
Posts: 609
What is the gear ratio?

89Saharagreen is offline   Quote Quick Reply
Old 01-13-2014, 07:47 AM   #3
Jeeper
 
YJGRIZZ90's Avatar
 
Join Date: Jan 2014
Location: California
Posts: 34
I think I read that it has 4:10.
__________________
I Go Topless
1990 Jeep Wrangler YJ
YJGRIZZ90 is offline   Quote Quick Reply
Old 01-13-2014, 11:13 AM   #4
Jeeper
 
Fabrokoner's Avatar
 
Join Date: Apr 2013
Location: Plymouth, CT
Posts: 345
I don't think many I6's came with 4.10s. I could be wrong. There should be a little metal tag on your diff cover that has your ratio. Assuming it hasn't been changed.
Fabrokoner is offline   Quote Quick Reply
Old 01-13-2014, 11:56 AM   #5
Jeeper
 
StanF's Avatar
 
Join Date: Jan 2013
Location: Austin, TX
Posts: 754
1987 with your drivetrain had 3.07 according to here:

Jeep Wrangler YJ - JP Magazine
__________________
1995 YJ, 4.0L, AX15, 3" susp lift; Lock Right in Dana 30; 8.8 LSD; Flat Tummy Tuck, 1" Daystar BL; 1" MORE MML; 35" MT/r Tires;

StanF Tummy Tuck, Ford 8.8, Gas Tank Lift, Rocker Guard Fab, Ammo Can Console
StanF is offline   Quote Quick Reply
Old 01-13-2014, 12:31 PM   #6
2.5L SYMPATHIZER

WF Supporting Member
 
W5KVV's Avatar
 
Join Date: Oct 2013
Location: S.E. Oklahoma
Posts: 820
It all depends on what you're going to do with the Jeep. Off Road quite a bit? Rocks? Mud? Trails?

3:07's are way too tall regardless. I would think 4:10's would be a good all around gear for a V8 powered Jeep.
__________________
1995 Rio Grande - 2.5 - AX5 - 160k -
4"RC - 1/2"booms - 33's -




W5KVV is offline   Quote Quick Reply
Old 01-13-2014, 12:36 PM   #7
Jeeper
 
Join Date: Oct 2013
Location: Fishers, IN
Posts: 267
What is your tire size?
Thomas S is online now   Quote Quick Reply
Old 01-13-2014, 01:04 PM   #8
It's a Jeep thing!

WF Supporting Member
 
western196611's Avatar
 
Join Date: Jun 2013
Location: Central Kansas
Posts: 694
I just went from 3.07 to 4.10, still have my I6. It woke my jeep up!! I would guess if you had 4.10's I'd keep them in there. If it was actually 3.07... get them out with a V-8 swap.

my .02.
__________________
1995, 4.0, 5 speed YJ, SOA, TC drop, 8.8 swap with 4.10 and LSD, e-grills bumper, 33" BF all terrains on 15" wheels.
western196611 is offline   Quote Quick Reply
Old 01-13-2014, 02:15 PM   #9
Jeeper
 
YJGRIZZ90's Avatar
 
Join Date: Jan 2014
Location: California
Posts: 34
You're right, it is a 3.07. And I plan on doing some trail riding and maybe a little more intense stuff as i do more mods. I have 33" tires right now. And I'll probly end up changing to 4:10
__________________
I Go Topless
1990 Jeep Wrangler YJ
YJGRIZZ90 is offline   Quote Quick Reply
Old 01-13-2014, 02:19 PM   #10
Jeeper
 
YJGRIZZ90's Avatar
 
Join Date: Jan 2014
Location: California
Posts: 34
One more question:
If I'm going to do a gear ratio change anyway, would I benefit from going to a 4:88 or 4:56?
Or should I just go for the 4:10?
__________________
I Go Topless
1990 Jeep Wrangler YJ
YJGRIZZ90 is offline   Quote Quick Reply
Old 01-13-2014, 02:38 PM   #11
Moderator

::WF Moderator::
 
harleydragon's Avatar
 
Join Date: Jul 2012
Location: south georgia
Posts: 3,907
stock axles probably won't last long behind a 350..rather than spending money on those I would look for some more heavy duty axles. look long and hard enough and you might find some that already are geared like you need
harleydragon is online now   Quote Quick Reply
Old 01-13-2014, 02:47 PM   #12
Jeeper
 
479jeep's Avatar
 
Join Date: Jan 2014
Location: Elkins Arkansas
Posts: 175
Quote:
Originally Posted by harleydragon View Post
stock axles probably won't last long behind a 350..rather than spending money on those I would look for some more heavy duty axles. look long and hard enough and you might find some that already are geared like you need
I would would upgrade your axles. Just from experience when I did my 350 conversion I broke 3 stock axle shafts with in a year.
479jeep is offline   Quote Quick Reply
Old 01-13-2014, 03:05 PM   #13
Jeeper
 
YJGRIZZ90's Avatar
 
Join Date: Jan 2014
Location: California
Posts: 34
Quote:
Originally Posted by harleydragon View Post
stock axles probably won't last long behind a 350..rather than spending money on those I would look for some more heavy duty axles. look long and hard enough and you might find some that already are geared like you need
Go for a Dana 44 or a Dana 60?
__________________
I Go Topless
1990 Jeep Wrangler YJ
YJGRIZZ90 is offline   Quote Quick Reply
Old 01-13-2014, 03:20 PM   #14
Jeeper
 
479jeep's Avatar
 
Join Date: Jan 2014
Location: Elkins Arkansas
Posts: 175
I went with a HP Dana 44 with chromoly shafts for the front and a 14 bolt for the rear. Haven't had a axle break sence.
479jeep is offline   Quote Quick Reply
Old 01-13-2014, 03:25 PM   #15
Jeeper
 
YJGRIZZ90's Avatar
 
Join Date: Jan 2014
Location: California
Posts: 34
Quote:
Originally Posted by 479jeep View Post
I went with a HP Dana 44 with chromoly shafts for the front and a 14 bolt for the rear. Haven't had a axle break sence.
Did you get em used or did you go brand new?
__________________
I Go Topless
1990 Jeep Wrangler YJ
YJGRIZZ90 is offline   Quote Quick Reply
Old 01-13-2014, 03:43 PM   #16
Jeeper
 
479jeep's Avatar
 
Join Date: Jan 2014
Location: Elkins Arkansas
Posts: 175
Quote:
Originally Posted by YJGRIZZ90 View Post
Did you get em used or did you go brand new?
I got the front from a 79 ford 3/4 ton for a $100. I rebuilt it with from hub to hub for about $1500 in parts . For the rear my friend gave me a 14 bolt out of a 79 suburban and I rebuilt it for about $1200 in parts.
479jeep is offline   Quote Quick Reply
Old 01-15-2014, 12:39 AM   #17
Jeeper
 
YJGRIZZ90's Avatar
 
Join Date: Jan 2014
Location: California
Posts: 34
Should I swap out the rear axle first? Or front first?
__________________
I Go Topless
1990 Jeep Wrangler YJ
YJGRIZZ90 is offline   Quote Quick Reply
Old 01-15-2014, 06:50 AM   #18
Moderator

::WF Moderator::
 
harleydragon's Avatar
 
Join Date: Jul 2012
Location: south georgia
Posts: 3,907
front axle will probably last longer than the rear..I would look for a set
harleydragon is online now   Quote Quick Reply
Old 01-15-2014, 02:15 PM   #19
Jeeper
 
YJGRIZZ90's Avatar
 
Join Date: Jan 2014
Location: California
Posts: 34
Quote:
Originally Posted by harleydragon View Post
front axle will probably last longer than the rear..I would look for a set
That's what I'm hoping for. But it's a money thing at this ooint
__________________
I Go Topless
1990 Jeep Wrangler YJ
YJGRIZZ90 is offline   Quote Quick Reply
Old 01-15-2014, 03:09 PM   #20
Moderator

::WF Moderator::
 
harleydragon's Avatar
 
Join Date: Jul 2012
Location: south georgia
Posts: 3,907
many times I find the cheapest route is to buy an entire 4x4 truck to use parts off of..many times you can find one with a cancer ridden body cheap
harleydragon is online now   Quote Quick Reply
Old 01-15-2014, 09:22 PM   #21
Jeeper
 
YJGRIZZ90's Avatar
 
Join Date: Jan 2014
Location: California
Posts: 34
Quote:
Originally Posted by harleydragon View Post
many times I find the cheapest route is to buy an entire 4x4 truck to use parts off of..many times you can find one with a cancer ridden body cheap
And use all of the parts like axle, TC and what not? What other things would I need to grab off of there?
__________________
I Go Topless
1990 Jeep Wrangler YJ
YJGRIZZ90 is offline   Quote Quick Reply
Old 01-16-2014, 07:06 AM   #22
Moderator

::WF Moderator::
 
harleydragon's Avatar
 
Join Date: Jul 2012
Location: south georgia
Posts: 3,907
I get the entire truck and use the entire drivetrain plus I end up using other small parts
harleydragon is online now   Quote Quick Reply
Old 01-25-2014, 04:18 AM   #23
Jeeper
 
YJGRIZZ90's Avatar
 
Join Date: Jan 2014
Location: California
Posts: 34
I know the 4 banger yj has 4:10 gears. But is it still a 35? Or is it a 44?
__________________
I Go Topless
1990 Jeep Wrangler YJ
YJGRIZZ90 is offline   Quote Quick Reply
Old 01-25-2014, 08:09 AM   #24
Moderator

::WF Moderator::
 
harleydragon's Avatar
 
Join Date: Jul 2012
Location: south georgia
Posts: 3,907
35
harleydragon is online now   Quote Quick Reply
Old 01-25-2014, 02:26 PM   #25
Jeeper
 
Wombat Ranger's Avatar
 
Join Date: Sep 2013
Location: Bonney Lake, WA
Posts: 474
Friend of mine swapped a tired 350/700r4 into his YJ. It's not fast but it sounds good and is a hoot to drive. It will light up the 33's easy. He is still on stock axles and 3.07's. It's a '90, originally a 4.2/ax15. I have his old trans in my jeep now, he let me have it for $80.

Anyway, every time I see him/his jeep, we laugh about how he beats on it all the time and has not broken the D35. My theory is that since he is still on 3.07's with 33's the usual weak point of the D35 (shafts) are not subjected to the snappy torque that comes with correct gearing. This moves the weak point to the driveline. He hasn't had any issues with that either though, so it must be fairly well setup.
__________________
'88 YJ 4.6L stroker, HEI, MC2150, AX15 swap
4" rub/ex, 33" BFG A/T's, SYE, rear locker
Stroker Thread
Wombat Ranger is offline   Quote Quick Reply
Old 01-25-2014, 02:36 PM   #26
Moderator

::WF Moderator::
 
harleydragon's Avatar
 
Join Date: Jul 2012
Location: south georgia
Posts: 3,907
Quote:
Originally Posted by Wombat Ranger View Post
Friend of mine swapped a tired 350/700r4 into his YJ. It's not fast but it sounds good and is a hoot to drive. It will light up the 33's easy. He is still on stock axles and 3.07's. It's a '90, originally a 4.2/ax15. I have his old trans in my jeep now, he let me have it for $80.

Anyway, every time I see him/his jeep, we laugh about how he beats on it all the time and has not broken the D35. My theory is that since he is still on 3.07's with 33's the usual weak point of the D35 (shafts) are not subjected to the snappy torque that comes with correct gearing. This moves the weak point to the driveline. He hasn't had any issues with that either though, so it must be fairly well setup.
there would be a lot more people driving chevy v8 jeeps if they ever drove one
harleydragon is online now   Quote Quick Reply
Old 01-25-2014, 03:33 PM   #27
Jeeper
 
Wombat Ranger's Avatar
 
Join Date: Sep 2013
Location: Bonney Lake, WA
Posts: 474
My stroker is stronger than his engine, but his isn't new either. I will never do a chevy swap simply because everyone and their mom has them. Which makes them lame in my opinion. Functional? Yep. Easy? Yep. Any better than any other carb'd V8 swap? Nope. So tired of seeing the same old thing done over and over. But I am the type of guy who likes building stuff just as much as actually driving it, so I know that can be a different perspective than most have.
__________________
'88 YJ 4.6L stroker, HEI, MC2150, AX15 swap
4" rub/ex, 33" BFG A/T's, SYE, rear locker
Stroker Thread
Wombat Ranger is offline   Quote Quick Reply
Old 01-25-2014, 03:43 PM   #28
Moderator

::WF Moderator::
 
harleydragon's Avatar
 
Join Date: Jul 2012
Location: south georgia
Posts: 3,907
one thing that makes them better is the availability of swap components,availability of performance products and a much lower cost of both...but,to me personally it is mainly because I have been wrenching on them for over 40 years
harleydragon is online now   Quote Quick Reply
Old 01-25-2014, 03:52 PM   #29
Jeeper
 
Wombat Ranger's Avatar
 
Join Date: Sep 2013
Location: Bonney Lake, WA
Posts: 474
See the swap components availability is a plus for those who want to drive a v8 jeep, not necessarily for people like me who like building just as much as driving. Anyway I am gonna duck out of here because the OP was asking about gears and all I did was derail this topic.
__________________
'88 YJ 4.6L stroker, HEI, MC2150, AX15 swap
4" rub/ex, 33" BFG A/T's, SYE, rear locker
Stroker Thread
Wombat Ranger is offline   Quote Quick Reply
Old 01-25-2014, 03:58 PM   #30
2xs
Cali Smog Nazi.

WF Supporting Member
 
2xs's Avatar
 
Join Date: Jun 2011
Location: Santa Rosa, Ca.
Posts: 2,545
Images: 3
Are you dead set on a Turbo 400? its one hell of a strong trans, but if you do alot of freeway driving you will want an overdrive trans, liek the 4L60E that came stock behind the Vortec 5.7L, or a 700R4 in older applications.

If you picj up a 96-99 GM K series tou can transplant the entire drivetrain, swap in an 8.8 from a late '90s Explorer and you end with a streetable, and off road worthy YJ!

Or for serious strength, go with a manual NV4500

Personally, I was planning on a 5.2L Dodge motor behind a NV3550.

Whatever you go with, get LOTS of opinions (but dont ask on Pirate4x4, you will get so much BS you will never want to go there again).

__________________
'93 Black YJ, 4.0L AX15 - UNDER CONSTRUCTION!
http://www.wranglerforum.com/f330/2x...ad-490865.html

Old Jeep that was totaled (and SOLD!):
http://www.wranglerforum.com/f330/2x...ad-101879.html
2xs is offline   Quote Quick Reply
Reply

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Jeep Wrangler Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
User Name:
If you do not want to register, fill this field only and the name will be used as user name for your post.
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



« rear end | 1993 yj »
Thread Tools

Posting Rules
You may post new threads
You may 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



logo carid shop wrangler parts carid fender flares custom wheels store avs deflectors at carid
» Rates
Get low rates on auto insurance in Canada!

» Network Links
»Jeep Parts
» Featured Product

All times are GMT -5. The time now is 07:34 AM.



Jeep®, Wrangler, Liberty, Wagoneer, Cherokee, and Grand Cherokee are copyrighted and trademarked to Chrysler Motors LLC.
Wranglerforum.com is not in any way associated with the Chrysler Motors LLC