I want to change my Front diff fluid, rear diff fluid and my transfer case fluid.

What is the best fluids to use and how much fluid do I put into each?

Thank you,

 

75w140 synthetic 3.5 quarts in both I believe. Don't forget the Friction modifier start with 2 quarts then add more if necessary. I used valvoline mostly because its all that I could find. I would have ordered redline if I had the time to wait for it. If you do use redline you don't need to get the friction modifier.

That information is located in the manual and the tech folder =D

 

What exactly does the friction modifier do?

I want my truck to burn both tires. For some reason I only have a one wheel peel.... Is that what the friction modifier does?

 

Read you manual... it tells you what to use.

Front and rear diff's are one thing and Mercon or Mercon V for the transfer case.

I personally use regular fluids as I change them on time. If I remember correctly, the rear-end diff spec is for a synthetic gear oil.

I prefer to use a single spec fluid rated for what the manual states and not "universal fluids" that are a compromise between various car/truck company specifications.

I use name brand fluids as frequent changes are always better than higher priced fluids left in longer... but that is me.

Just check you manual and look around for that spec.. then see what brands are offered in the spec you need... then make your decision.

 

Agree with above!

 

So I found Mobil 1, 75W140 but it says right on the bottle its for light truck and SUV's. Whats up with that? I also found Trans-X Posi-Trac imited slip gear oil additive. Should I put a tube in the front and another in the rear or just one in the rear? Sorry guys I never got an owners manual and i havent got the book on the truck yet..

I appreciate the help..

 

The front is 80w-90 dino gear oil and uses under 3qts. The rear is 75w-140 synthetic w/ friction modifier and uses under 4 qts. Some have used the Mobil-1 with good luck, just make sure it says LS (limited slip) on the bottle. I just purchased all Motorcraft fluids for the front and rear diff. The rear diff needs 8oz of XL-3 modifier if you use Motorcraft fluid.

 

The front and rear differential fluids from Ford are very good. No need to use a different fluid in my opinion. If you just have to use a different fluid in the rear differential, I have heard from quite a few folks that use and like the Royal Purple fluid (it already contains the friction modifier). Some folks use the Ford rear differential fluid but add less of the friction modifier to get better performance. You can do this, but it is at the risk of reliability. My advice is to research this well before you go this route. I use SynchroMax from Royal Purple in my transfer case.

 

You can download a copy of the owners manual here. https://www.fleet.ford.com/maintenan...ls/default.asp

 

FYI:

<TABLE style="WIDTH: 634pt; BORDER-COLLAPSE: collapse" cellSpacing=0 cellPadding=0 width=845 border=0 x:str><COLGROUP><COL style="WIDTH: 634pt; mso-width-source: userset; mso-width-alt: 30902" width=845><TBODY><TR style="HEIGHT: 12.75pt" height=17><TD class=xl24 style="BORDER-RIGHT: windowtext 1pt solid; BORDER-TOP: windowtext 1pt solid; BORDER-LEFT: windowtext 1pt solid; WIDTH: 634pt; BORDER-BOTTOM: #d4d0c8; HEIGHT: 12.75pt; BACKGROUND-COLOR: #ffcc99" width=845 height=17>Rear Differential Fluid Specs from the MANUAL:</TD></TR><TR style="HEIGHT: 12.75pt" height=17><TD class=xl25 style="BORDER-RIGHT: windowtext 1pt solid; BORDER-TOP: #d4d0c8; BORDER-LEFT: windowtext 1pt solid; BORDER-BOTTOM: #d4d0c8; HEIGHT: 12.75pt; BACKGROUND-COLOR: #ffcc99" height=17>F250/F350 10.5 Axle - 6.9 pints of 75W-140 Synthetic</TD></TR><TR style="HEIGHT: 12.75pt" height=17><TD class=xl26 style="BORDER-RIGHT: windowtext 1pt solid; BORDER-TOP: #d4d0c8; BORDER-LEFT: windowtext 1pt solid; BORDER-BOTTOM: #d4d0c8; HEIGHT: 12.75pt; BACKGROUND-COLOR: #ffcc99" height=17>F350 Dana 80 Axle - 8.5 pints of 75W-90 Synthetic</TD></TR><TR style="HEIGHT: 12.75pt" height=17><TD class=xl26 style="BORDER-RIGHT: windowtext 1pt solid; BORDER-TOP: #d4d0c8; BORDER-LEFT: windowtext 1pt solid; BORDER-BOTTOM: #d4d0c8; HEIGHT: 12.75pt; BACKGROUND-COLOR: #ffcc99" height=17>F450/F550 Dana S110/S130 Axle - 14.0 pints of 75W-140 Synthetic</TD></TR></TBODY></TABLE>


<TABLE style="WIDTH: 634pt; BORDER-COLLAPSE: collapse" cellSpacing=0 cellPadding=0 width=845 border=0 x:str><COLGROUP><COL style="WIDTH: 634pt; mso-width-source: userset; mso-width-alt: 30902" width=845><TBODY><TR style="HEIGHT: 12.75pt" height=17><TD class=xl24 style="BORDER-RIGHT: windowtext 1pt solid; BORDER-TOP: windowtext 1pt solid; BORDER-LEFT: windowtext 1pt solid; WIDTH: 634pt; BORDER-BOTTOM: #d4d0c8; HEIGHT: 12.75pt; BACKGROUND-COLOR: #ccffcc" width=845 height=17>Dana 60 Front Axle (factory oil is dino) with 35 splines:</TD></TR><TR style="HEIGHT: 16.5pt; mso-height-source: userset" height=22><TD class=xl25 style="BORDER-RIGHT: windowtext 1pt solid; BORDER-TOP: #d4d0c8; BORDER-LEFT: windowtext 1pt solid; WIDTH: 634pt; BORDER-BOTTOM: windowtext 1pt solid; HEIGHT: 16.5pt; BACKGROUND-COLOR: #ccffcc" width=845 height=22 x:str="'- use any properly rated synthetic oil 80W-90 gear oil (the manual states 5.8 pints, some on the Forum say it takes 6.5 pints I think they are mistaken)">- use any properly rated synthetic oil 80W-90 gear oil (the manual states 5.8 pints, some on the Forum say it takes 6.5 pints)</TD></TR></TBODY></TABLE>

<TABLE style="WIDTH: 634pt; BORDER-COLLAPSE: collapse" cellSpacing=0 cellPadding=0 width=845 border=0 x:str><COLGROUP><COL style="WIDTH: 634pt; mso-width-source: userset; mso-width-alt: 30902" width=845><TBODY><TR style="HEIGHT: 12.75pt" height=17><TD class=xl24 style="BORDER-RIGHT: #d4d0c8; BORDER-TOP: #d4d0c8; BORDER-LEFT: #d4d0c8; WIDTH: 634pt; BORDER-BOTTOM: #d4d0c8; HEIGHT: 12.75pt; BACKGROUND-COLOR: #ccffff" width=845 height=17>Transfer Case:</TD></TR><TR style="HEIGHT: 12.75pt" height=17><TD class=xl24 style="BORDER-RIGHT: #d4d0c8; BORDER-TOP: #d4d0c8; BORDER-LEFT: #d4d0c8; WIDTH: 634pt; BORDER-BOTTOM: #d4d0c8; HEIGHT: 12.75pt; BACKGROUND-COLOR: #ccffff" width=845 height=17 x:str="'- use any properly rated synthetic oil (approximately 2 qts): I put in 3 quarts to get it to the top (fill bolt) when I changed mine!">- use any properly rated synthetic oil (approximately 2 qts): I put in 3 quarts to get it to the top (fill bolt) when I changed mine!</TD></TR><TR style="HEIGHT: 12.75pt" height=17><TD class=xl25 style="BORDER-RIGHT: #d4d0c8; BORDER-TOP: #d4d0c8; BORDER-LEFT: #d4d0c8; WIDTH: 634pt; BORDER-BOTTOM: #d4d0c8; HEIGHT: 12.75pt; BACKGROUND-COLOR: #ccffff" width=845 height=17 x:str="'- Mercon/MerconV ATF">- Mercon/MerconV ATF</TD></TR></TBODY></TABLE>