Go Back   Ford Truck Enthusiasts Forums > Performance, Engines & Troubleshooting > Modular V10 (6.8l)
Sign in using an external account
Register Forgot Password?

Modular V10 (6.8l) SPONSORED BY:

Welcome to Ford-Trucks Forums!
Welcome to Ford-Trucks.com.

You are currently viewing our forums as a guest, which gives you limited access to view most discussions and access our other features. By joining our community you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is fast, simple and absolutely free so please, join the Ford-Trucks Forums community today!

LinkBack Thread Tools Search this Thread
Old 08-29-2014, 10:49 PM
7racecar7 7racecar7 is offline
Freshman User
Join Date: May 2014
Posts: 28
7racecar7 is starting off with a positive reputation.
Front 75W-90 gear oil or 75W-140gear oil

Seen a few posts on this topic just wanted to get some advice, below is what manual says for a 2001 F250

Differential lubricant
Differential lubricant
Front axle SAE 75W-90 QL synthetic gear lubricant
Rear axle
Ford 10.50 inch axles. SAE 75W-140 GL synthetic gear lubricant*
Dana 80 axles SAE 75W-90 QL synthetic gear lubricant*
Dana 135 axles SAE 80W-90 QL synthetic gear lubricant*

The differential has been collecting a drop on the bottom since I picked up the truck about 3 months ago, going to fix it.

Found this deal with a step by step but looking for what oil to use...I might be splitting hairs here but just want to be sure...is SAE 75W-90 QL the right stuff for the front seen a few where ford now says 75W-140 in the front too?

The Step by step
Welcome to guzzle's Front Differential Maintenance Web Page

Thanks for any help
Reply With Quote
Old 08-30-2014, 07:30 PM
Krewat's Avatar
Krewat Krewat is offline
Super Moderator
Join Date: Jul 2002
Location: Long Island USA
Posts: 34,541
Krewat has a superb reputationKrewat has a superb reputationKrewat has a superb reputationKrewat has a superb reputationKrewat has a superb reputationKrewat has a superb reputationKrewat has a superb reputationKrewat has a superb reputationKrewat has a superb reputationKrewat has a superb reputationKrewat has a superb reputation
I don't think my 2001 required synthetic in the front.

The Ford "Sterling" 10.25/10.5" rear axle REQUIRES synthetic. Synthetic for these is usually only available in xxx/140 oil. (see note below)

The Dana front axles (or any Dana for that matter I think) do NOT require synthetic.

Plain old 75/90 gear oil will work great in the fronts.

Note: I think the Ford Sterling axles require it because early on in their life, they had a lot of failures using plain 75/90 gear oil. I truly believe it has to do with the small front pinion bearing, and who they sourced it from. But that's just my own suspicion. To counter all the failures they were seeing, a synthetic oil solved the problem.

In my experience, every Ford diff I've ever seen used a non-Timken front pinion bearing, and they all showed inordinate amounts of wear and scoring early in their life - at less than 75K miles, they all showed a lot of heat. Synthetic solves that.

No so in the Dana diffs.
- art k. - Moderator for the Superduty, V10, 6.2L and FE forums
'13 Taurus SHO 3.5L Ecoboost w/Perf Pkg
'01 F250SD SC SB XLT V10 4x4 Volant CAI Hedman headers 5-star custom tunes on SCT X3
'97 Cougar XR7 30th Anniv Edition 4.6L
'74 F250 Highboy FE390 deceased!
I've been wrong before, I'll be wrong again. Just wait and see. ®
Reply With Quote
Old 08-31-2014, 03:54 AM
speakerfritz's Avatar
speakerfritz speakerfritz is offline
Elder User
Join Date: Jul 2013
Posts: 800
speakerfritz is starting off with a positive reputation.
75W90 is GL-4
75W140 is GL-5

since GL-5 damages soft metals, I would never use it when GL-4 (the correct gear oil for boxes with soft metals) is called for.

Hellwig 7677Rear Sway Bar; Hellwig 61904 Pro-Series Helper Spring with Silent Feature; 2 ofRancho Suspension/Monroe RS999046 Rear Rancho RS9000; 2 of Rancho RS999042RS9000XL Series Shock; Rancho RS98510 Steering Stabilizer Kit; Dee Zee DZ43203Tailgate Assist Shock
Reply With Quote
Old 08-31-2014, 03:54 AM

Similar Threads
Thread Thread Starter Forum Replies Last Post
4WD differential fluids bismic 6.0L Power Stroke Diesel 3 07-08-2012 03:35 AM
Dana 60 gear oil wideglidewoody00 Super Duty & Heavy Duty 4 08-29-2009 10:42 PM
05 F150 SCAB Front Diff. Oil? jjed2007 Oil & Lubrication 10 02-27-2008 03:47 PM
75w140 Synthetic Gear Oil Saguaro_7.3 1994.5 - 1997 7.3L Power Stroke Diesel 3 10-08-2005 03:47 PM
What differential oil do I use? (Haynes is confusing) Dave85zxt Clutch, Transmission, Differential, Axle & Transfer Case 4 12-31-2003 10:56 AM

Go Back   Ford Truck Enthusiasts Forums > Performance, Engines & Troubleshooting > Modular V10 (6.8l)

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 On
Trackbacks are On
Pingbacks are On
Refbacks are On

Forum Jump

All times are GMT -5. The time now is 06:35 AM.

Powered by vBulletin® Version 3.8.7 AC1
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Advertising - Terms of Use - Privacy Statement - Jobs
This forum is owned and operated by Internet Brands, Inc., a Delaware corporation. It is not authorized or endorsed by the Ford Motor Company and is not affiliated with the Ford Motor Company or its related companies in any way. Ford® is a registered trademark of the Ford Motor Company.

vbulletin Admin Backup