Can you find the Friction Modifier at a reguler autoparts store? Im wondering because someone said "Ford Friction Modifier"... So is it just a ford thing or what?

 

You can, but its not motorcraft. I got a bottle at the dealership last week for 6.50 after tax. Use the ford stuff.

 

i bought the amsoil friction modifier i have yet to add it.. no catter from the amsoil sever gear

 

besides, if you want to add modifier, just go to the left hand, top side of the differential, you will see your ABS sensor. Take the bolt out, pry out the piece that goes into the diff.(gingerly) with a flat head screwdriver(it's placed in there with a rubber gasket at the inside, top). Disconnect connector and clean sensor with DENATURED ALCOHOL,( as you will see it's filthy), install your desired amount of modifier and reinstall sensor, finger tighten, then 1/4 turn with wrench. (well, depends on how strong your fingers are) anyway, bout 10 ft/lbs should be way good,(it's just to hold it in place), alittle rtv around the sensor body above the gasket should help keep out moisture.

 

I wouldn't do that - I'd open the fill plug and suck 4 ounces of fluid out and replace it with the modifier. You really don't want to overfill it, that's inviting seal leaks.

 

https://www.f150online.com/forums/ot...tial-help.html

https://www.f150online.com/forums/20...how-often.html

2nd link is my post after I successfully changed my rear pinion seal.
I got advice from someone who has been a mechanic for atleast 28 yrs.

But both links will answer all questions

 

Thats what I did

 

Well, as some of ya'll remember I replaced my rear axle bearings and seals...and of course I had to open my diff. I used blue RTV on the COVER after cleaning both the pumpkin and cover extremely well. I bolted it up and filled with Royal Purple. I have NOT added any FM, and I don't feel any chattering or anything.

My suggestion is to fill it up and drive it for a couple weeks to a month to see if your vehicle needs/wants the FM. You can always add it!---DirtySCREW

 

I have been driving mine for over a year and a half with the Royal Purple without adding any additional FM and i have not had one peep out of my rear end.....lol..

 

I just ordered 3 qts. of Severe Gear 75-140 and 2 qts. of Severe Gear 75-90 and one 4oz. tube of FM from Amsoil. Hopefully it'll all be here by next Wednesday and I'll change it all out, plus an oil change, over the long weekend. Gonna have to sacrifice an afternoon of chasing woods goats I guess. I'll fill the rear with SG first, then if it chatters I'll add the FM.

Any suggestions on the front diff? Looks to me like I need to pull the cover to drain, replace it and the fill port is on the right side of the diff. case. That sound about right? I read in a manual or a forum somewhere that the front has a drain plug, but I haven't located it yet.

David

 

The front should have a drain plug. It is a flat plug, witha square socket.

 

GlenR, Thanks, I had found the fill/inspection plug on the right side, but not the drain. I'll have another look before I crack the plate on the front. Could be covered by the skid plate. I'll have all that off anyway, so it should all be easier to change.

Thanks again,

David

 

What drain plug?

The drain is you taking the cover off.

Break open the fill plug First though. Sometimes itis difficult.

 

Hambone,

That was my original question on the front diff. Is there a drain plug? The Haynes manual says to pull the drain plug, but I didn't find one. Was asking if I missed something. Glen seems to think there is, but may be mistaken.

Any and all information appreciated.

David

 

Didn't mean to mislead anyone. I was referring to my Expedition. it has a drain plug in teh front differential.