How to tell what gears I have? - Ford Powerstroke Diesel Forum
Suspension & Steering Discuss OEM & aftermarket suspension, lifts, air ride suspension, shocks, steering components, etc.

Powerstroke.org is the premier Diesel Truck Forum on the internet. Registered Users do not see the above ads.
Reply
 
LinkBack Thread Tools Display Modes
  #1  
Old 04-27-2010, 10:53 AM
Member
 

Join Date: Dec 2009
Location: surfing, spearfishing, using my powerstroke to tow boats to the river!
Posts: 52
Thanks: 0
Thanked 0 Times in 0 Posts
Feedback Score: 0 reviews
How to tell what gears I have?

Hey guys, I bought my truck used and it already had a 6" lift on 37s. I'm curious what gears I have on my truck and want to know if the prior owner switched them from stock. I haven't gotten a programmer yet so my speedo hasn't been calibrated for the larger tires. When my speedo says 55mph I'm down around 1550-1600rpms. And when my speedo says 55mpg I'm actually going about 60mpg calculated by gps. Anyone have an idea of what I've got? Also, if I pull the rear cover off how do I go about calculating my gearing? Thanks!!!
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2  
Old 04-27-2010, 12:37 PM
Compression Ignition Addict
 

Join Date: Aug 2008
Location: Texas Hill Country
Posts: 819
Thanks: 0
Thanked 2 Times in 2 Posts
Feedback Score: 0 reviews
I would wager that you have 3.73 gears, but there should be a small metal tag on the rear diff under one of the diff cover bolts.

Mark
Reply With Quote Quick reply to this message
  #3  
Old 04-27-2010, 12:40 PM
Member
 

Join Date: Dec 2009
Location: surfing, spearfishing, using my powerstroke to tow boats to the river!
Posts: 52
Thanks: 0
Thanked 0 Times in 0 Posts
Feedback Score: 0 reviews
I swapped my cover out and have an '08 cover now. I still had my stock 3.73 tag on there when I switched out the covers but I know thats not a sure bet they are still stock.
Reply With Quote Quick reply to this message
  #4  
Old 04-27-2010, 03:55 PM
Compression Ignition Addict
 

Join Date: Jun 2007
Location: crescent city
Posts: 198
Thanks: 0
Thanked 0 Times in 0 Posts
Feedback Score: 0 reviews
isnt it something like every turn of the axle how ever many turns the diff did thats the gear ratio or something? idk it was just a guess
Reply With Quote Quick reply to this message
  #5  
Old 04-27-2010, 05:57 PM
Super Moderator


 

Join Date: Mar 2008
Location: Abingdon, Md.
Posts: 11,958
Thanks: 3
Thanked 21 Times in 13 Posts
Feedback Score: 3 reviews
Yes, jack it up, put it in neutral, have someone turn a wheel 1 revolution and count the revolutions the driveshaft makes. If it goes around about 3 3/4 times they are 3.73's. If it goes around a little more than 4 times it's a 4.10, 4 1/2 times 4.56, etc.
Reply With Quote Quick reply to this message
  #6  
Old 04-28-2010, 08:57 AM
Compression Ignition Addict
 

Join Date: Jun 2007
Location: crescent city
Posts: 198
Thanks: 0
Thanked 0 Times in 0 Posts
Feedback Score: 0 reviews
cool man i was right for once
Reply With Quote Quick reply to this message
  #7  
Old 04-28-2010, 08:59 AM
Member
 

Join Date: Dec 2009
Location: surfing, spearfishing, using my powerstroke to tow boats to the river!
Posts: 52
Thanks: 0
Thanked 0 Times in 0 Posts
Feedback Score: 0 reviews
sweet! Thanks
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
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:
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.



Thread Tools
Display Modes

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



All times are GMT -8. The time now is 05:26 AM.


Powered by vBulletin® Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Search Engine Optimization by vBSEO 3.6.1
Garage Plus, Vendor Tools vBulletin Plugins by Drive Thru Online, Inc.

vB.Sponsors