I want to add a new cover to the differential on my truck (2003 XLT FX4). I'd like to get one that has a little added capacity and a drain plug. I found a nice looking one for $85 on ebay, but I'm not sure which differential it's for. I emailed the company, but all they told me was this: The Differential cover part # HZ- 5079 is for stock applications. This cover will fit these 12 bolt applications:

1986-2003 E-250 2WD/4WD.
1986-2003 E-350 2WD/4WD.
1986-2003 F-150 truck 2WD/4WD.
1986-2003 F-250 truck 2WD/4WD.
1986-2003 F-350 truck 2WD/4WD.
1986-2003 Expedition 2WD/4WD.
1986-2003 Excursion 2WD/4WD.

I don't know, so here's the question: Are the covers for the 9.75 and 10.25 the same? Also for anyone that has this cover, does it add any capacity? Here's the link to the auction: http://cgi.ebay.com/ebaymotors/ALUMI...5393QQtcZphoto

Thanks for any help anyone can provide.

 

I like the one I saw once, it had the F-150 badge smelted into the cover. But then again with all that dirt and stuff under there, why would you want a chrome diff. cover???

 

This one isn't chrome, it's polished aluminum. I'm looking at it because aluminum is a better heatsink than steel is and will do a better job of keeping the fluid cool. I'm not necessarily concerned with the look because of exactly what you said. Loads of dirt and where I live road salt under there.

 

Go with mag hytech. I went from the stock capacity (like 1, maybe two qts?) to well over 4. Its awesome and is said to run about 50 degrees cooler. It has a magnetic drain plug, a filler hole, a place already done up for a temp guage, and a magnetic dipstick! Yes a dipstick in your diff!! Its sooo sweet! You can check to see if water got in, to check the level... etc!
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Also got the mag hytech tranny pan. Went from stock fluid level (16 qts?) to 23 qts!!

 

Not exactly sure which one mine is, but I do know it is Made in the USA.
I got it from DiffWorks in Corona, CA.

951-549-6780

This is the best picture I have now. I will try and post some later. It is basically a finned aluminum cover with a drain plug and holds more oil and keeps the rear end cooler. Basically just like the mag-hytec, minus the dipstick.
I think both are nice.