I think it is the next thing on the list to be replaced along with front and rear diff fluids.
How do I determine what fuel filter I need? And can I use a cheaper brand like purolater or driveworks ooor should I just spend the extra couple bucks on the motorcraft part.
Also why I'm at it, what would you guys suggest for differential fluids.

 

Purolator is probably the cheapest fuel filter I'd use, but consider how rarely the filter gets changed and how little the better brands (MotorCraft, Wix) will cost over the life of the truck. Any place that sells them either has a book/computer you can use to find the right one, or they'll look it up for you. If your fuel lines have metal fittings at the filter, read this carefully before beginning:



Use any good gear oil; preferrably a synthetic, but it's not critical. Haynes or the tag on the diff will tell you what weight (probably 75W90). It usually takes a little more than 3 bottles for both axles, and the rear is NOT filled - read this:

 

Thanks again steve.
Where could I get the friction modifier for the limited slip and how much will it cost?

 

A lot of the better gear oils that you can get already have it in there I believe (says something about it on the bottle). I don't know if steve is talking about an additional additive on top of that tho.

 

There is a guy in a trench coat on the corner of Fifth and Jepep that sells 2 bottles for a Dollar three nintey five. He will also sell you one for the price of two if you only need one! j/k

Sorry man I couldn't help myself.
You can get it at the Dealer for the Ford stuff, or it can be found at most Auto parts stores, or Summit Racing & Jegs. You can open up a whole new debate as to which one is best.

 

The important info in that caption was how high to fill it. Is your diff a stock limited slip (Trac-Lok)? Is it still working? If either answer was NO, then you don't need any additive. It won't hurt, but it won't help.

 

Steve, will going over the fill level in that caption cause the seals at the axles to leak?

 

Yea, I just did mine and it took just under 4 quarts, Haynes told me to fill it to the line so I did...

 

My stock limited slip, posi, trac lok whatever the hell it's called works I know that.
I checked the make sure the diffs have fluid, but with all of the records of the truck since 1994 a change in diff fluids was never mentioned.
And believe me these records are detailed, wash n wax, every oil change, headlight out, dash switch so on and so forth.

 

No it wouldn't say it's the CAUSE, but if they're already bad, then overfilling can make that problem appear. Why - are yours leaking?

 

Yes just a tad. I wondered if that contributed to it.

Thanks Steve
Jim

 

Lift the axle & try to shake the tire straight up-&-down. If it moves enough to notice, the bearings are probably cutting into the shaft.

 

Will do. Hope that aint what is giong on.

Russo sorry for thread jacking.

 

It's all good, I enjoy learning new things whether it applies to my truck or not.
I read almost every thread on here just to learn.
Since I'm here to learn I have to ask quite possibly my stupidest question yet, would the front be an open diff or possibly a limited slip trac lok or whatever.

 

Front will be open.