Rear Diff Flud - Ford Truck Enthusiasts Forums



6.0L Power Stroke Diesel 2003 - 2007 F250, F350 pickup and F350+ Cab Chassis, 2003 - 2005 Excursion and 2003 - 2009 van

Rear Diff Flud

Reply
 
 
 
Thread Tools Search this Thread
  #1  
Old 07-06-2017, 11:02 AM
akblackfoot's Avatar
akblackfoot akblackfoot is online now
Senior User
Thread Starter
 
Join Date: Mar 2016
Posts: 407
akblackfoot is gaining momentum as a positive member of FTE.
Rear Diff Flud

Change the fluid in my differentials a couple weekends ago. I used Mobile 1 Synthetic 75W-140LS in my rear diff. Said it has the friction modifier in it and I haven't noticed anything odd or out of the ordinary after changing it. Had some people claim you still have to add friction modifier or it will screw up the rear end. Any truth to that?
Reply With Quote
  #2  
Old 07-06-2017, 11:09 AM
Blakshukvw Blakshukvw is offline
Elder User
 
Join Date: Jul 2016
Location: Blue Springs, mo
Posts: 644
Blakshukvw has a good reputation on FTE.Blakshukvw has a good reputation on FTE.
You should be ok if it had modifier in it. The Amsoil is the same way. I personally use it in my truck's but I still add some modifier anyway. It won't hurt to add additional modifier.
Reply With Quote
  #3  
Old 07-06-2017, 11:41 AM
MisterCMK's Avatar
MisterCMK MisterCMK is online now
Avid Winter Hater
 
Join Date: Mar 2003
Location: Maple Grove, MN
Posts: 23,738
MisterCMK has a superb reputationMisterCMK has a superb reputationMisterCMK has a superb reputationMisterCMK has a superb reputationMisterCMK has a superb reputationMisterCMK has a superb reputationMisterCMK has a superb reputationMisterCMK has a superb reputationMisterCMK has a superb reputationMisterCMK has a superb reputationMisterCMK has a superb reputation
If it isn't chattering there is no reason to add any.

Adding more will make the limited slip unit less effective.
Reply With Quote
  #4  
Old 07-06-2017, 12:32 PM
bismic's Avatar
bismic bismic is online now
Post Fiend
 
Join Date: Nov 2003
Posts: 16,481
bismic has a superb reputationbismic has a superb reputationbismic has a superb reputationbismic has a superb reputationbismic has a superb reputationbismic has a superb reputationbismic has a superb reputationbismic has a superb reputationbismic has a superb reputationbismic has a superb reputationbismic has a superb reputation
From 50k miles on, I have uses the Mobil 1 Synthetic 75W-140LS also. Never have added extra friction modifier to it. 194k miles now, no issues.
Reply With Quote
  #5  
Old 07-06-2017, 01:30 PM
akblackfoot's Avatar
akblackfoot akblackfoot is online now
Senior User
Thread Starter
 
Join Date: Mar 2016
Posts: 407
akblackfoot is gaining momentum as a positive member of FTE.
Thanks everybody. I was pretty sure this was the case but just needed some confirmation from more knowledgeable people.
Reply With Quote
  #6  
Old 07-07-2017, 05:48 PM
Pest007's Avatar
Pest007 Pest007 is offline
Senior User
 
Join Date: Jun 2004
Location: Goodyear, AZ
Posts: 418
Pest007 is starting off with a positive reputation.
How much does it take to change? I'm needing to change mine and want to buy the upgraded Ford diff cover with the cooling fins
Reply With Quote
  #7  
Old 07-07-2017, 07:31 PM
akblackfoot's Avatar
akblackfoot akblackfoot is online now
Senior User
Thread Starter
 
Join Date: Mar 2016
Posts: 407
akblackfoot is gaining momentum as a positive member of FTE.
3.5 quarts or so. Got 4 and had some left over.
Reply With Quote
  #8  
Old 07-08-2017, 11:18 AM
amdriven2liv's Avatar
amdriven2liv amdriven2liv is offline
I'm hitting easy street
 
Join Date: Nov 2009
Location: Southern, Washington
Posts: 6,303
amdriven2liv has a superb reputationamdriven2liv has a superb reputationamdriven2liv has a superb reputationamdriven2liv has a superb reputationamdriven2liv has a superb reputationamdriven2liv has a superb reputationamdriven2liv has a superb reputationamdriven2liv has a superb reputationamdriven2liv has a superb reputationamdriven2liv has a superb reputationamdriven2liv has a superb reputation
I used the Valvoline oil for limited slip. Every thing was fine until I started pulling this trailer around the country. I had to add 1 bottle of fords additive. Just thought I should pass this along.
Reply With Quote
  #9  
Old 07-08-2017, 10:14 PM
Dr.Huxtable's Avatar
Dr.Huxtable Dr.Huxtable is offline
Senior User
 
Join Date: Nov 2015
Location: Spartanburg, SC
Posts: 367
Dr.Huxtable is gaining momentum as a positive member of FTE.Dr.Huxtable is gaining momentum as a positive member of FTE.
Ugh this thread just reminded me I need to do this. Been putting it off because I wanna upgrade the cover at the same time. Money and time, two things there's never enough of!
Reply With Quote
  #10  
Old 07-09-2017, 09:12 AM
DSMMH's Avatar
DSMMH DSMMH is offline
Posting Guru
 
Join Date: Jun 2006
Posts: 1,335
DSMMH has a great reputation on FTE.DSMMH has a great reputation on FTE.DSMMH has a great reputation on FTE.DSMMH has a great reputation on FTE.DSMMH has a great reputation on FTE.DSMMH has a great reputation on FTE.
I upgraded the diff cover several years ago. The new capacity is 6 quarts. I use Royal Purple 75W-140 and two years ago added AR9100. That took care of a chattering problem I had.

Ed
Reply With Quote
  #11  
Old 07-09-2017, 05:27 PM
akblackfoot's Avatar
akblackfoot akblackfoot is online now
Senior User
Thread Starter
 
Join Date: Mar 2016
Posts: 407
akblackfoot is gaining momentum as a positive member of FTE.
I have the Ford aluminum diff cover and it took less than 4 quarts so I'm sure it depends on which one you have.
Reply With Quote
  #12  
Old 07-09-2017, 07:14 PM
TooManyToys.'s Avatar
TooManyToys. TooManyToys. is online now
Postmaster
 
Join Date: Dec 2014
Location: Jersey Shore
Posts: 4,479
TooManyToys. is a splendid one to beholdTooManyToys. is a splendid one to beholdTooManyToys. is a splendid one to beholdTooManyToys. is a splendid one to beholdTooManyToys. is a splendid one to beholdTooManyToys. is a splendid one to beholdTooManyToys. is a splendid one to behold
No matter the cover, the bottom of the fill port in the diff is the correct amount for coverage.

At 100k I ent no additive as y limited slip was limited no more. Didn't change by not using the additive. At some point I'll pull the clutches and replace.
Reply With Quote
  #13  
Old 07-10-2017, 11:29 AM
jlillie jlillie is offline
Senior User
 
Join Date: Nov 2002
Location: Cape Coral USA
Posts: 212
jlillie is gaining momentum as a positive member of FTE.jlillie is gaining momentum as a positive member of FTE.
I just did mine. Got the aluminum cover, put a black paint job on it, with the stainless allen head bolts. Used Amsoil with most of a bottle of friction modifier, but the point i wanted to make is i also used a Lube Locker gasket which saved me from having to use permatex and waiting 24hrs before i could add the oil back. No leaks so far.
Reply With Quote
  #14  
Old 07-10-2017, 03:59 PM
MisterCMK's Avatar
MisterCMK MisterCMK is online now
Avid Winter Hater
 
Join Date: Mar 2003
Location: Maple Grove, MN
Posts: 23,738
MisterCMK has a superb reputationMisterCMK has a superb reputationMisterCMK has a superb reputationMisterCMK has a superb reputationMisterCMK has a superb reputationMisterCMK has a superb reputationMisterCMK has a superb reputationMisterCMK has a superb reputationMisterCMK has a superb reputationMisterCMK has a superb reputationMisterCMK has a superb reputation
If you're going through the trouble of opening up the differential, you might as well toss a true trac in there and have a traction device that actually works and then never worry about friction modifier ever again.
Reply With Quote
  #15  
Old 07-10-2017, 04:14 PM
wedge542's Avatar
wedge542 wedge542 is online now
Elder User
 
Join Date: Jan 2007
Posts: 631
wedge542 is gaining momentum as a positive member of FTE.
Quote:
Originally Posted by MisterCMK View Post
If you're going through the trouble of opening up the differential, you might as well toss a true trac in there and have a traction device that actually works and then never worry about friction modifier ever again.
Do you have one in yours,it doing ok on the street or towing heavy, im installing clutches,side gears,spider and gears in mine now but with 340k guess its time.
Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
Friction modifier for Electronic Locking Diff? jdp526 1999 to 2016 Super Duty 6 05-17-2017 09:38 AM
1999 2WD Limited Slip Rear Differential 1L243 Clutch, Transmission, Differential, Axle & Transfer Case 1 04-11-2017 08:58 AM
Changing our rear diff fluid question Edgar7 6.7L Power Stroke Diesel 8 03-31-2017 06:44 AM
Changing Rear Diff Fluid 1L243 1999 - 2003 7.3L Power Stroke Diesel 22 03-26-2017 04:41 PM
open diff..... anthonym92 1987 - 1996 F150 & Larger F-Series Trucks 3 11-27-2016 09:13 PM


Go Back   Ford Truck Enthusiasts Forums >

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

Forum Jump


All times are GMT -5. The time now is 10:53 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.