Diff fluid change

[SaNnDnSurF]

05 las what viscosity do I need to buy also what is the friction modifier where do I find it and how much do I use in the front and the rear?

 

[Zmann]

son do you need a manual ? there free online , all the specs are here , don't need to log in just fill out the specifics https://owner.ford.com/servlet/Cont...torPage&BackToLogin=Owner/Page/OwnerGuidePage

an your diffs should have a tag with specs
no limited slip in a stock front and it does not need to be synthetic oil and no additive

the rear is likely a LS and requires synthetic (74-140 IIRC?) most non ford fluids have a LS additive according to posters on the forums

but best is to only put additive in if you hear a chatter around corners ford sells the additive if u need it

 

[SaNnDnSurF]

Yes I'm getting the chatter when turning yes and was gonna change the fluid over the break.

 

[DEEZUZ]

75W140

 

[ghohouston]

^ like ctc said, 75w140, and id go ahead and buy one bottle of friction modifier from ford, and add it to the rear. Also, now this is all preference, but we use ford grey silicone at work to reseal the diff covers, but you can use what you like. Ford grey holds up better than ANY silicone ive ever seen

 

[DEEZUZ]

Ford fluid, Ford friction, Ford Rtv. Thick bead, circle the bolt holes, hand tighten all bolts in cross pattern, let sit for 10 mins, the torque bolts in pattern.

 

[SaNnDnSurF]

Thanks guys one bottle of fric modifier is 8oz right?

 

[Zmann]

I can't see any reason to add the modifier specially if the lube you choose is not Ford and already may have a LS additive

but either way you Should monitor the sounds otherwise just adding modifier when it's not needed can lessen the ability of the limited slip.

now if you don't want a customer to come back with a sound complaint then some shops may dump it in?

a bottle of modifier is 4oz and be forewarned it smells like all hell

 

[HeavyAssault]

This: http://www.mobiloil.com/USA-English...il_1_Fully_Synthetic_Gear_Lube_75W-140LS.aspx

 

[Zmann]

the above Mobil 1 is the easiest 75-140 syn to find IMHO

and much cheaper when you don't have to mess with the stink asss modifier

 

[DEEZUZ]

I'm running amsoil and I don't remember if I put the modifier in, but I do have a chatter while turning. It's Not a audible thing, the whole truck feels it. Think I'll just put some valvoline and Modifier in soon