Changed differential fluid

[sharef]

I changed the differential fluid in my 2002 explorer. I replaced it with amsoil 75W140 synthetic. I had previously read on another web site to add 7oz. of friction modifier to the fluid. So I did and now I am getting a loud roar in the rear that wasn't there before. Could this extra 3oz. of friction modifier cause this to happen?

 

[trucku]

Do you have a limited slip rear? If not no modifier needed.

Pull the fill plug and let any extra drain out.

I don't think you should have a loud roar because of the modifier. Worse comes to worse, drain it and fill without modifier.

 

[Exproblems]

I changed the differential fluid in my 2002 explorer. I replaced it with amsoil 75W140 synthetic. I had previously read on another web site to add 7oz. of friction modifier to the fluid. So I did and now I am getting a loud roar in the rear that wasn't there before. Could this extra 3oz. of friction modifier cause this to happen?

Even if you have an "Open Rear Diff" like me, adding the Friction Modifier to it will not harm a thing. I spoke to my "trusted" mechanic who has over 30+ years experience about this and that is what he told me. He just said the friction modifier is something the "Limited Slip" diffs need, but won't harm a thing on open diffs if added by accident. Even though Ford calls for only 4 ounces of Friction Modifier to be added, my mechanic said he always dumps the whole 7 ounce tube of modifier into the rear diffs when he changes the fluid on a Limited Slip diff for his customers. He said the extra modifier won't harm anything. On the loud roar problem now, did you correctly top off the rear diff on a level surface with enough gear oil? The rear diffs hold 1.60 to 1.75 quarts of fluid depending on your specific rear diff.

 

[sharef]

I put in about 1 3/4 qts. plus the 7oz. of modifier. After I drove it and it was roaring so bad I added the rest of the second quart and it didn't make a change. It's odd, but when I make a strong turn to the left the roar almost goes away. Almost making me think about a wheel bearing. But what has me confused is the roar wasn't there until I changed the differential fluid.

 

[swshawaii]

Check wheel bearings first. 18 TSB's that are drive line related. GL

http://www.revbase.com/BBBMotor/

 

[sharef]

Thanks swshawaii I will check the wheel brgs. I know this is a question that I should know the answer too but do the technical service bulletins have anything to do with a recall?

 

[swshawaii]

http://autorepair.about.com/library/a/1h/bl608h.htm

 

[TheGTkid]

as for the process, was it difficult to change? I plan on changing the fluid in mine soon
any suggested methods?