Does anybody know what color the ford factory friction modifier is? The reason i am asking, is i went to check my diff fluid level and when i did i found this real thick grey fluid, about the consistency and color of the aluminum anti-seize on the fill plug. Just seeing if i need to do a fluid change soon or if it can wait awhile.

 

Doesn't sound normal to me. How many miles since it was changed last?

 

Wirelessly posted (Timberwolf)

Sounds like water contamination.

 

It has just under 60k, and i don't think it has ever been changed

 

Never been in any water that deep.

 

Wirelessly posted (Timberwolf)

Maybe the fill plug had anti seize on it in the first place? BTW, have you checked your maintenance book?

 

Thats how mine was in my 7.5 inch when I drained it. It had 125k on it. The stuff like glooped out. It was super thick.

 

The maintenance book says 100k for non synthetic rear diff fluid and synthetic fluid does not need to be changed, i am just going to top it off and leave it be for awhile.

 

I'd change it when you can. That's not normal.

 

both my front and rear diffs were that color when i drained them in this truck. nasty, thick sh*t. I'd drain and refill with 80w90.

Friction modifier is a blueish/greenish color and you only need it if you have a LS

 

for the color it is dark gray.

as for you replacing the fluid i would do it now. just pick up the gasket and some fluid and call it a day.

 

friction modifier isn't dark gray. i can go pour some out right now to prove it


when you replace the fluid get grey RTV for sealing the cover back up.

 

Motor Craft Bottle

clear bottle or the white one ?

 

I have 5 motorcraft bottles of it

EDIT nvm i have 2 now lol

 

Weird the service manual says 100k that sounds like way too long to leave it in there.

 

Wirelessly posted

Change the fluid. I change mine every 10k. My front fluid is dark green cuz its a pain up there at the moment. She's all loose and sloppy also leaking some fluid.

 

Is the plug magnetic? If so, you're probably seeing the metal it picks up from the fluid.
If there are no big chunks it's perfectly normal, though I'd never leave gear oil in for 100k.

 

Change it man,3 quarts of 80w90,3 oz tube of friction modifier and a tube of silicone is all you need. You can get the gear oil that already is mix with the friction modifier. The premixed is all i could really find in bakersfield when i did my gears.

 

Wirelessly posted

Royal purple has the modifier in it already. I've never used RTV to seal the cover always the gasket

 

I got to checking, all that grey stuff was just on the fill plug. BTW, yes, the fill plug is magnetic.

 

Like Pedro, mine was like paste. Grey, thick, paste. Awful stuff.

 

Wirelessly posted

If seen some SD at work come in with legit chocolate pudding consistency for fluid