Notices
1999 - 2003 7.3L Power Stroke Diesel  
Sponsored by:
Sponsored by: DP Tuner

Rear Diff Fluid

Thread Tools
 
Search this Thread
 
Old Dec 14, 2011 | 09:08 PM
  #1  
Deluxe06's Avatar
Deluxe06
Thread Starter
|
4000 rounds a min
Joined: Apr 2010
Posts: 2,223
Likes: 0
From: Albemarle NC
Club FTE Gold Member
Rear Diff Fluid

What Synthetic Gear Lube do you guys prefer for the rear diff?
 
Reply
Old Dec 14, 2011 | 09:21 PM
  #2  
woodnthings's Avatar
woodnthings
Cargo Master
15 Year Member
Photogenic
Joined: May 2010
Posts: 3,047
Likes: 10
From: Snohomish, WA
Club FTE Silver Member

I ended up using Amsoil and a bottle of their friction modifier. It was close to the same price as everything else and the local dealer is close to me. He had everything in stock that I needed.
 
Reply
Old Dec 14, 2011 | 09:22 PM
  #3  
A/Ox4's Avatar
A/Ox4
9 ECHO 1
15 Year Member
Liked
Joined: Aug 2009
Posts: 12,467
Likes: 58
From: Missouri
Club FTE Silver Member

Valvoline.

But anything with a friction modifier (if you have a limited slip) will do.
 
Reply
Old Dec 14, 2011 | 09:26 PM
  #4  
mueckster's Avatar
mueckster
Lead Driver
20 Year Member
Photogenic
Photoriffic
Shutterbug
Joined: Jun 2003
Posts: 8,298
Likes: 25
From: Damon (South East Texas)
I use Mobil 1. IIRC, it has friction modifiers in it, but I don't really need them with my Truetrac.
 
Reply
Old Dec 14, 2011 | 09:56 PM
  #5  
white Buffalo's Avatar
white Buffalo
Post Fiend
Joined: Sep 2006
Posts: 7,426
Likes: 6
From: Sioux Falls, SD
I've tested two different brands in my F-250. Royal Purple and Schaeffer's 75W-140. Wasn't very happy with the UOA reports on the Royal Purple - the viscosity sheared down and the iron wear was much higher than compared to the Schaeffer's UOA. Most of the miles were towing.

Royal Purple UOA



Schaeffer UOA

 
Reply
Old Dec 14, 2011 | 10:29 PM
  #6  
Deluxe06's Avatar
Deluxe06
Thread Starter
|
4000 rounds a min
Joined: Apr 2010
Posts: 2,223
Likes: 0
From: Albemarle NC
Club FTE Gold Member
Thanks Guys, Hey Rich thanks for posting those UAs good info. Just for giggles lets keep this going post up what Gear Lube you put in your differential when you did a lube change.
 
Reply
Old Dec 14, 2011 | 11:32 PM
  #7  
SpringerPop's Avatar
SpringerPop
Hotshot
Veteran: Air Force
20 Year Member
Liked
Community Favorite
Joined: Jan 2002
Posts: 17,988
Likes: 207
From: La La Land
Club FTE Silver Member

Mobil 1.

Pop
 
Reply
Old Dec 14, 2011 | 11:52 PM
  #8  
BigAlsPSD's Avatar
BigAlsPSD
Post Fiend
Joined: May 2009
Posts: 5,470
Likes: 3
From: Pea Ridge, AR
Club FTE Gold Member
I tend to use a lot of the Mobil 1 products, Mobil 1 is in the rear, but Front has Motive Gear because it was all I could find of quality locally at the time.
 
Reply
FTE Stories

Ford Trucks for Ford Truck Enthusiasts

story-0

Top 10 Fords at 2026 Carlisle Ford Nationals

 Joe Kucinski
story-1

3 Best / 3 Worst Parts of Modern Ford Ownership

 Brett Foote
story-2

10 Amazing Upgrades That Solve Common Ford Truck Owner Headaches

 Pouria Savadkouei
story-3

Every 2026 Ford Engine Explained

 Brett Foote
story-4

10 Ugly Ford Trucks That We Still Kinda Love

 Joe Kucinski
story-5

10 Things Every Truck Owner NEEDS (2026 Edition)

 Michael S. Palmer
story-6

Rezvani's Latest Post-Apocalyptic Monster Is a Ford F-150 Raptor Underneath

 Verdad Gallardo
story-7

Top 10 Most Expensive Ford Trucks Ever Sold on Bring a Trailer

 Joe Kucinski
story-8

2027 Ford Super Duty Buyer's Guide (Every Model, Engine, & Package)

 Brett Foote
story-9

Top 10 Ford Truck Tragedies

 Joe Kucinski
Old Dec 15, 2011 | 04:39 AM
  #9  
Journeymaaann's Avatar
Journeymaaann
Senior User
15 Year Member
Joined: Dec 2006
Posts: 122
Likes: 0
From: Long Island,NY
Club FTE Gold Member
I like to use Mobil 1. How many remember their commercial where they hammered a nail with a banana @ -30F? then poured their oil.
 
Reply
Old Dec 15, 2011 | 04:52 AM
  #10  
Franko72's Avatar
Franko72
Molon Labe
15 Year Member
Joined: Dec 2006
Posts: 5,272
Likes: 1
From: Alaska
Club FTE Silver Member

Another vote for Mobil one. I added some modifier, someone told me that it needs a bit more to meet Ford Recomendations.
 
Reply
Old Dec 15, 2011 | 08:40 AM
  #11  
rufushusky's Avatar
rufushusky
Cargo Master
Joined: Jul 2011
Posts: 2,675
Likes: 975
From: Walpole, MA
I have Red Line 75w-140, didn't need any FM, in the rear and Mobil 1 775w-90 in the front. Seems to work fine.
 
Reply
Old Dec 15, 2011 | 06:12 PM
  #12  
AMG-SM's Avatar
AMG-SM
Senior User
Joined: Jan 2011
Posts: 362
Likes: 0
From: SF Bay, CA
I also used the Redline. Got a gallon of it from Summit just in case I spilled some while filling, which I did...
Red Line Synthetic Oil 57915 - Red Line Synthetic Gear Oil - Overview - SummitRacing.com
 
Reply
Old Dec 15, 2011 | 07:40 PM
  #13  
stevestroke01's Avatar
stevestroke01
Senior User
15 Year Member
Liked
Joined: Jul 2006
Posts: 226
Likes: 0
From: Jeffersonville , Indiana
I used Mobil 1 front and rear.
 
Reply
Old Dec 15, 2011 | 09:28 PM
  #14  
Ponyboychris's Avatar
Ponyboychris
Lead Driver
15 Year Member
Joined: Jan 2007
Posts: 6,708
Likes: 5
From: Kiowa CO
Club FTE Silver Member

Valvoline in both diffs for me.
 
Reply
Old Dec 15, 2011 | 10:57 PM
  #15  
jc8825's Avatar
jc8825
Posting Guru
Joined: Jul 2010
Posts: 1,711
Likes: 0
From: Fort Worth
I used Valvoline SynPower. It had the friction modifier in it for the LS.
 
Reply



All times are GMT -5. The time now is 10:22 AM.

story-0
Top 10 Fords at 2026 Carlisle Ford Nationals

Slideshow: Top 10 Fords at 2026 Ford Nationals

By Joe Kucinski | 2026-06-09 11:10:08


VIEW MORE
story-1
3 Best / 3 Worst Parts of Modern Ford Ownership

Based on years of owning multiple modern Ford products.

By Brett Foote | 2026-06-09 10:53:36


VIEW MORE
story-2
10 Amazing Upgrades That Solve Common Ford Truck Owner Headaches

SPONSORED: From muddy boots to rain-soaked cargo, these upgrades address some of the most common frustrations Ford truck owners face every day.

By Pouria Savadkouei | 2026-06-08 18:50:34


VIEW MORE
story-3
Every 2026 Ford Engine Explained

Here's everything you need to know about every Ford engine available for the 2026 model year.

By Brett Foote | 2026-06-05 12:58:01


VIEW MORE
story-4
10 Ugly Ford Trucks That We Still Kinda Love

Slideshow: 10 ugly Ford trucks that we still kinda love.

By Joe Kucinski | 2026-06-03 09:51:16


VIEW MORE
story-5
10 Things Every Truck Owner NEEDS (2026 Edition)

Slideshow: the best gifts for dads & grads

By Michael S. Palmer | 2026-06-03 15:43:58


VIEW MORE
story-6
Rezvani's Latest Post-Apocalyptic Monster Is a Ford F-150 Raptor Underneath

Slideshow: Called the Fortress, the 850-horsepower pickup combines Raptor underpinnings with military-inspired features, survival equipment, and a starting price of $285,000.

By Verdad Gallardo | 2026-06-03 11:38:36


VIEW MORE
story-7
Top 10 Most Expensive Ford Trucks Ever Sold on Bring a Trailer

Slideshow: 10 most expensive Ford trucks ever sold on Bring a Trailer.

By Joe Kucinski | 2026-05-27 16:24:34


VIEW MORE
story-8
2027 Ford Super Duty Buyer's Guide (Every Model, Engine, & Package)

Here's everything that has changed for the latest model year.

By Brett Foote | 2026-05-27 16:17:28


VIEW MORE
story-9
Top 10 Ford Truck Tragedies

Slideshow: Top 10 Ford truck tragedies.

By Joe Kucinski | 2026-05-18 19:34:33


VIEW MORE