What Gears? - Ranger-Forums - The Ultimate Ford Ranger Resource


Drivetrain Tech General discussion of drivetrain for the Ford Ranger.

Reply
 
LinkBack Thread Tools Search this Thread
  #1  
Old 03-07-2011
leadfoot's Avatar
Member
Thread Starter
 
Join Date: Oct 2007
Location: MA
Posts: 894
What Gears?

I have a 1998 4x4 4.0L OHV
It came stock with 3.73 and 235/70/R16 = 29.0" tires
Right now it has 3.73 gears and 265/75/R16 = 31.6" tires
It seems to be making the torque converter do too much work and my highway mileage isn't any better since my driving is not a "steady 65" in which case these gears would do good.

So I am thinking of regearing but can't decide between 4.11 and 4.56 gears.

Looking at this chart and approximating the rpm values for the 31.6" tires I end up with these values.
http://www.4lo.com/calc/geartable.htm
multiplied by 0.75 to account for OD at 65mph

3.73 - 29.0" - 2107 rpm
3.73 - 31.5" - 1940 rpm
4.11 - 31.5" - 2137 rpm
4.56 - 31.5" - 2372 rpm

Stock:
Max BHP = [email protected]
Max TQ = [email protected]

Now I see that 4.11 gears would set my truck back to around stock but with the higher rotational mass and rolling resistance of the tires I was thinking of going to the next step up. I am just worried that it would be too over-geared however it is closer to and still below the max TQ rpm. Most of the driving I do isn't on the highway so I would like a little better pep and acceleration through town. Is there anyone else running this setup, do these figures seem right?
Reply With Quote
  #2  
Old 03-07-2011
silverfox's Avatar
Member
 
Join Date: Jul 2008
Location: Taft, Ca
Posts: 1,040
Quote:
Originally Posted by leadfoot View Post
I have a 1998 4x4 4.0L OHV
It came stock with 3.73 and 235/70/R16 = 29.0" tires
Right now it has 3.73 gears and 265/75/R16 = 31.6" tires
It seems to be making the torque converter do too much work and my highway mileage isn't any better since my driving is not a "steady 65" in which case these gears would do good.

So I am thinking of regearing but can't decide between 4.11 and 4.56 gears.

Looking at this chart and approximating the rpm values for the 31.6" tires I end up with these values.
http://www.4lo.com/calc/geartable.htm
multiplied by 0.75 to account for OD at 65mph

3.73 - 29.0" - 2107 rpm
3.73 - 31.5" - 1940 rpm
4.11 - 31.5" - 2137 rpm
4.56 - 31.5" - 2372 rpm

Stock:
Max BHP = [email protected]
Max TQ = [email protected]

Now I see that 4.11 gears would set my truck back to around stock but with the higher rotational mass and rolling resistance of the tires I was thinking of going to the next step up. I am just worried that it would be too over-geared however it is closer to and still below the max TQ rpm. Most of the driving I do isn't on the highway so I would like a little better pep and acceleration through town. Is there anyone else running this setup, do these figures seem right?


I went from stock 27.4's with 4.10's to 31's and 4.56's. Its close to stock but honestly wish i would have gone with 4.88's.Im in the same boat as you most of my driving is city.Geared and tuned im getting a max of around 15 Mpg's city if i baby it and around 22 Mpg's hwy.I would glady sacrific a few Hwy Mpg's for a few more city Mpg's.IMO go with the 4.56's if you dont like it bump up to 33's down the road.

Edit: try this calculator
http://www.superioraxlegear.com/calc...re-height.html
Reply With Quote
  #3  
Old 03-07-2011
leadfoot's Avatar
Member
Thread Starter
 
Join Date: Oct 2007
Location: MA
Posts: 894
Quote:
Originally Posted by silverfox View Post
I went from stock 27.4's with 4.10's to 31's and 4.56's. Its close to stock but honestly wish i would have gone with 4.88's.Im in the same boat as you most of my driving is city.Geared and tuned im getting a max of around 15 Mpg's city if i baby it and around 22 Mpg's hwy.I would glady sacrific a few Hwy Mpg's for a few more city Mpg's.IMO go with the 4.56's if you dont like it bump up to 33's down the road.

Edit: try this calculator
http://www.superioraxlegear.com/calc...re-height.html
Do you have a 4 cylinder of something because that gearing seems really high to start with?
That calculator was nice, I just wish it was .75 overdrive but it gives me a good enough idea.
Reply With Quote
  #4  
Old 03-07-2011
leadfoot's Avatar
Member
Thread Starter
 
Join Date: Oct 2007
Location: MA
Posts: 894
Does anyone know what the front diff is in a 1998 4.0 ranger, Iknow my rear is a 28 spline 8.8" but what is the front, a dana 28 or dana 35?
Reply With Quote
  #5  
Old 03-07-2011
leadfoot's Avatar
Member
Thread Starter
 
Join Date: Oct 2007
Location: MA
Posts: 894
Well I think I am just going to go with 4.11 gears to set it back to stock. Does anyone know a good place to buy gears?

I found these, Are they the right ones and is this everything I need?
http://completeoffroad.com/i-369355-...deal-4-11.html
The front one is the one I am really unsure about, it seems like it is for a jeep, would the install kit work?
http://completeoffroad.com/i-367062-...stall-kit.html

Last edited by leadfoot; 03-07-2011 at 01:41 PM.
Reply With Quote
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
gears gears gears which to choose? craigs2869 Drivetrain Tech 14 10-07-2011 03:32 AM
High Pinion Gears and Low Pinion Gears ? Downey Drivetrain Tech 14 01-13-2009 10:19 AM
Gears and more Gears (R & P)... zabeard General Ford Ranger Discussion 21 12-02-2007 11:02 PM
Front Gears same as Rear Gears / HUM?? Wingmandan Drivetrain Tech 9 08-22-2007 10:44 AM
Which 4.56 gears and locker? Best Gears pushdeck Drivetrain Tech 8 03-05-2007 06:19 PM


Thread Tools Search this Thread
Search this Thread:

Advanced Search

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 -6. The time now is 07:38 PM.


We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.