Question Changing Rear Diff. Fluid in my F250 - F-Series & SuperDuty Diesel Forums

RJDiesel · 11-15-2011, 08:35 PM

I am looking to change my fluid in my rear differential on my F250 and I was looking for some recommendations on fluid and I keep reading about a modifier additive. Any suggestions would,,,,,, as always be greatly appreciated.

majek5 · 11-15-2011, 08:47 PM

Use what the manual says for the weight. Most synthetics have the modifier in them already. If you get "chirping" on tight turns, you will need to add some modifier.

Stroked68 · 11-15-2011, 08:52 PM

Im actually gonna be doin the same thing to my 99. I bought royal purple oils. Also now would be the time to change out your rear diff cover if its gettin rusty. You can always treat and paint your old cover. I bought a new 08 and up rear diff for the new superduty's cause they are aluminum and have fins. Paid $56 at Ford. Just got to get some longer bolts. Dont forget the black silicone to reseal it.

BIG JOE · 11-15-2011, 09:00 PM

Poke Red Line Synthetic Oil for some info about synthetics ?

I have it my dif & 6 spd tranny. used it for Years & Years. 150K on my 2K. Served me well. No Tranny or Dif failures on anything i've owned.. with it in it.

Lil' pricey but good stuff.

Joe

WD40 · 11-15-2011, 11:10 PM

I just changed mine 2 weeks ago, it only had 35,000 on it and it was Royal Purple. It was still real clean. I went back with the Valvoline 75-140 synthetics and it has the modifier already in it. I have the Mag-Hytec Differential Cover on my truck, so it takes 6 qt. at $14.88 a QT. to fill that sucker up. LOL
Doug

BIG JOE · 11-16-2011, 12:32 AM

Quote:

Originally Posted by WD40

I just changed mine 2 weeks ago, it only had 35,000 on it and it was Royal Purple. It was still real clean. I went back with the Valvoline 75-140 synthetics and it has the modifier already in it. I have the Mag-Hytec Differential Cover on my truck, so it takes 6 qt. at $14.88 a QT. to fill that sucker up. LOL
Doug

I hear ya Doug. The Redline has been in there.. longer than I like.. for the towing we do. I'm thinking about changing it out.. but it looks as Clean & Clear.. as the day I put it in. (@ 6 qts, @ $16 per)

I drained a bit out of the bottom drain.. (sure like that Mag-Hytec low point drain).. clean there too.. just a fine touch of normal wear.

Joe

Stroked68 · 11-16-2011, 07:43 PM

I havnt read my royal purple labels yet but does royal purple have modifiers already in them??

majek5 · 11-16-2011, 08:29 PM

Quote:

Originally Posted by Stroked68

I havnt read my royal purple labels yet but does royal purple have modifiers already in them??

Yes it does.

RJDiesel · 11-16-2011, 09:15 PM

Royal Purple sounds like the stuff to get for my rig!!

Fine69 · 11-16-2011, 09:22 PM

Any GOOD quality synthetic will work fine. Mobil 1, Amsoil, Redline, etc, all make good oils. I've never cared for Royal Purple, just doesn't seem to hold up to all their claims.

11-15-2011, 08:35 PM	#1
RJDiesel SDD Junior Member Join Date: Jun 2009 Location: Waterbury CT Posts: 35 Thanks: 7 Thanked 0 Times in 0 Posts View Photos By: RJDiesel	Changing Rear Diff. Fluid in my F250 I am looking to change my fluid in my rear differential on my F250 and I was looking for some recommendations on fluid and I keep reading about a modifier additive. Any suggestions would,,,,,, as always be greatly appreciated.

11-15-2011, 08:47 PM	#2
majek5 SDD Member Join Date: Sep 2009 Location: Northern Il Posts: 114 Thanks: 3 Thanked 16 Times in 14 Posts	Use what the manual says for the weight. Most synthetics have the modifier in them already. If you get "chirping" on tight turns, you will need to add some modifier. __________________ 06 6.0 CCLB KR FX4 stock...

11-15-2011, 08:52 PM	#3
Stroked68 This is FORD Country Join Date: Apr 2010 Location: Eudora, KS Posts: 944 Thanks: 11 Thanked 64 Times in 63 Posts View Photos By: Stroked68	Im actually gonna be doin the same thing to my 99. I bought royal purple oils. Also now would be the time to change out your rear diff cover if its gettin rusty. You can always treat and paint your old cover. I bought a new 08 and up rear diff for the new superduty's cause they are aluminum and have fins. Paid $56 at Ford. Just got to get some longer bolts. Dont forget the black silicone to reseal it. __________________ 1999 Ford F250 Superduty 4x4 sb ext cab 7.3L DIY Intake-MBRP 4" turbo back smokers kit with dual 6" Miter stacks-Autometer UltraLite Triple pillar gauge KMC HPX SS Crossover Line-Shimmed FPR 74-75psi AIH delete-ZooDad Mod-08 rear diff cover-Harpoon mod-Hutch mod-Recon LED smoked cab lights Bed liner on bottom 1/4 of truck-Fumoto drain valve 275k and counting!

11-15-2011, 11:10 PM	#5
WD40 SDD Senior Member Join Date: Aug 2005 Location: Benton Arkansas & McAllen Posts: 2,755 Thanks: 57 Thanked 110 Times in 106 Posts View Photos By: WD40	I just changed mine 2 weeks ago, it only had 35,000 on it and it was Royal Purple. It was still real clean. I went back with the Valvoline 75-140 synthetics and it has the modifier already in it. I have the Mag-Hytec Differential Cover on my truck, so it takes 6 qt. at $14.88 a QT. to fill that sucker up. LOL Doug __________________ 2006 Ford F-350 Crew Cab Lariat 4X2 PSD 6.0 TorqShift Automatic Transmission, MAG-HYTEC DIFF COVERS Bama ZooDad If you think the 6.0 is bad.....Get a 6.4 2004 35 ft Hitch Hiker 16589 EW. Doug Is it time to go camping yet?

11-16-2011, 07:43 PM	#7
Stroked68 This is FORD Country Join Date: Apr 2010 Location: Eudora, KS Posts: 944 Thanks: 11 Thanked 64 Times in 63 Posts View Photos By: Stroked68	I havnt read my royal purple labels yet but does royal purple have modifiers already in them?? __________________ 1999 Ford F250 Superduty 4x4 sb ext cab 7.3L DIY Intake-MBRP 4" turbo back smokers kit with dual 6" Miter stacks-Autometer UltraLite Triple pillar gauge KMC HPX SS Crossover Line-Shimmed FPR 74-75psi AIH delete-ZooDad Mod-08 rear diff cover-Harpoon mod-Hutch mod-Recon LED smoked cab lights Bed liner on bottom 1/4 of truck-Fumoto drain valve 275k and counting!

11-15-2011, 09:00 PM	#4
BIG JOE SDD Senior Member Join Date: Apr 2005 Location: CenCal Posts: 4,376 Thanks: 101 Thanked 391 Times in 380 Posts	Poke Red Line Synthetic Oil for some info about synthetics ? I have it my dif & 6 spd tranny. used it for Years & Years. 150K on my 2K. Served me well. No Tranny or Dif failures on anything i've owned.. with it in it. Lil' pricey but good stuff. Joe

11-16-2011, 09:15 PM	#9
RJDiesel SDD Junior Member Join Date: Jun 2009 Location: Waterbury CT Posts: 35 Thanks: 7 Thanked 0 Times in 0 Posts View Photos By: RJDiesel	Royal Purple? Royal Purple sounds like the stuff to get for my rig!!

11-16-2011, 09:22 PM	#10
Fine69 Senior Member Join Date: Mar 2006 Location: Cranberry Twp,PA Posts: 837 Thanks: 80 Thanked 31 Times in 29 Posts View Photos By: Fine69	Any GOOD quality synthetic will work fine. Mobil 1, Amsoil, Redline, etc, all make good oils. I've never cared for Royal Purple, just doesn't seem to hold up to all their claims. __________________ ----- Bob ------ -2009 F350 CCLB Job 2, Lariat Ultimate, 6.4, Auto, H&S Mini-Max, KEM tunes, S&B Intake, DPF/DOC delete, DieselSite Coolant filter, 2.5" levelling kit, Bilstein 5100's, 325/65/R18 Nitto Terra Grapplers on Weld EVO Cheyenne 8 wheels, Mag-Hytec Diff covers, Carriage Works Billet Grille, Line-X Xtra Spray in Bedliner, Dura Flap Mudflaps, Weatherguard toolbox. Ordered 4-13-09, Built 6-17-09, Delivered 7-6-09 http://community.webshots.com/user/FineFord

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode