Diff Gearing - Ford Powerstroke Diesel Forum

 
LinkBack Thread Tools Display Modes
post #1 of 8 Old 04-05-2012, 07:11 PM Thread Starter
Powerstroke.org Rookie
 
Join Date: Apr 2012
Posts: 2
Thanks: 0
Thanked 0 Times in 0 Posts
Mentioned: 0 Post(s)
Quoted: 0 Post(s)
Feedback Score: 0 reviews
Diff Gearing

Thinking about getting a '99 F250 but am thinking about increasing the ratios in the diffs to something that will extend mileage a little more. Not planning on doing a whole lot of towing, but will be off-roading for hunting...nothing "dedicated." Does anyone know if a lower ratio than 3.55 is out there for the diffs in this year range and who might make them?
mhanly3 is offline  
post #2 of 8 Old 04-05-2012, 07:34 PM
Compression Ignition Addict
 
Join Date: Mar 2008
Posts: 238
Thanks: 0
Thanked 0 Times in 0 Posts
Mentioned: 0 Post(s)
Quoted: 0 Post(s)
Feedback Score: 0 reviews
Hum, I think you have either a 10.25 or 10.5 sterling. Same basic diff, different pinion gear shaft length and bearings, and sometimes 3 pinions versus 2. But anyhow, ratios go up to 1:3.08 I believe. I say up, because I think you are wanting to re-gear "up" in ratio to a lower number. If I'm wrong, the other end of the spread is 1:4.56 or maybe 4.88

2006 built 05/05 XLT CC DRW PSD. Captain chairs, sunroof, polished aluminum wheels, 6speed, manual 4x4. 285K miles with 130K problem free miles on new engine.
RatherBNtheWoods is offline  
post #3 of 8 Old 04-05-2012, 08:27 PM
Serving Our Country!
 
JSchuricht's Avatar
 
Join Date: Aug 2007
Location: Manor, TX
Posts: 2,969
Thanks: 0
Thanked 25 Times in 24 Posts
Mentioned: 1 Post(s)
Quoted: 0 Post(s)
Feedback Score: 2 reviews
OBS had a 10.25, SD's have 10.5.

JSchuricht is offline  
post #4 of 8 Old 04-06-2012, 08:55 AM Thread Starter
Powerstroke.org Rookie
 
Join Date: Apr 2012
Posts: 2
Thanks: 0
Thanked 0 Times in 0 Posts
Mentioned: 0 Post(s)
Quoted: 0 Post(s)
Feedback Score: 0 reviews
Thanks. Was trying to find out through VINs or the DANA website. This narrows it down a bunch.
mhanly3 is offline  
post #5 of 8 Old 04-07-2012, 07:51 PM
Member
 
Join Date: Sep 2011
Location: NW Oklahoma
Posts: 60
Thanks: 0
Thanked 0 Times in 0 Posts
Mentioned: 0 Post(s)
Quoted: 1 Post(s)
Feedback Score: 0 reviews
3.08 would make it a dog. Something in the 3.3-3.4 range with 30-31" tires (narrow 32's would be ok with 3.4) makes a good combo for weight and RPM.

Gets me 24mpg in a ex cab 4x4 6.5 chevy. I have 3.08's and 29" tires on my 82 6.2 (non turbo) and it sucks for speed but will crusie like no other.

06 K2500HD CCSB Duramax 6 speed Allison 225K: 5" Diamondeye, EFI LIVE Tow/Econ, Transgo Jr, Amsoil, fuel rail shim, 20" XD wheels FOR SALE

03 K1500HD CCSB 6.0L 4L80 Quadrasteer EFI Live Propane WIFES
00 K3500 CCLB 6.5L 4L80 DRW
95 K1500 ECSB 6.5L 4L80 SRW
94 K3500 SCLB 6.5L NV4500 SRW
93 K3500 SCLB 6.5L NV4500 DRW C&C

Looking to add a F450-550 7.3 4x4
tanman_2006 is offline  
post #6 of 8 Old 07-20-2012, 03:27 AM
Compression Ignition Addict
 
Therabbittree's Avatar
 
Join Date: Nov 2011
Location: LaGrangeville,NY
Posts: 350
Thanks: 0
Thanked 8 Times in 6 Posts
Mentioned: 0 Post(s)
Quoted: 1 Post(s)
Feedback Score: 0 reviews
look into the 3.31 gear swap. The newer trucks use them alot. I'm looking to swap these into my cummins 6spd manual excursion etc.. currently i have 4.10.. the 6 spd makes the rpm pretty high etc. Only issue is cost I heard the ford dealer is only place to get the new 3.31 gears.. and they may be costly...
Thanks,
deo
Therabbittree is offline  
post #7 of 8 Old 07-20-2012, 04:24 AM
Banned
 
Join Date: Sep 2008
Location: Fort Bragg, NC/Buff, NY/Midlothian, VA
Posts: 5,630
Thanks: 0
Thanked 2 Times in 2 Posts
Mentioned: 0 Post(s)
Quoted: 0 Post(s)
Feedback Score: 0 reviews
My automatic OBS has 410's and it has tons of power and great cruising rpms. Granted, I'm on 35's. My 6spd super duty, dont remember gears, would rip a house off of its foundation though.
85_305 is offline  
post #8 of 8 Old 07-20-2012, 12:06 PM
Powerstroke.org Fanatic
 
Join Date: May 2012
Location: Renton, WA
Posts: 104
Thanks: 0
Thanked 0 Times in 0 Posts
Mentioned: 0 Post(s)
Quoted: 0 Post(s)
Feedback Score: 0 reviews
Quote:
Originally Posted by Therabbittree View Post
look into the 3.31 gear swap. The newer trucks use them alot. I'm looking to swap these into my cummins 6spd manual excursion etc.. currently i have 4.10.. the 6 spd makes the rpm pretty high etc. Only issue is cost I heard the ford dealer is only place to get the new 3.31 gears.. and they may be costly...
Thanks,
deo
Those new trucks have a five speed tranny and towing package for the tranny. That's how they can get away with the low ratio and still be usable.

Sent from my EVO using AutoGuide.Com Free App

99 F250 CCLB Pretty much a stocker
87' BMW DINAN M6 Too many mods to list
StoneGuy is offline  
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Ford Powerstroke Diesel 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:
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:
OR

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.



Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



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 On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome