hey there been reading on a couple of the ford related sites that the rear ends on expeditions are really craptacular and that by adding a finned differential cover most of these overheating problems will be ''taken care of" any advice or suggestions

 

its true, if you put a finned diff cover on the fins help cool the rear end down and prevent it from f-n up, my buddy has one on his 08 f250 we drove for 50 miles ont he highway, when we stoped i checked to see how hot it was, and it wasnt very hot at all it was pretty cool, i would recomend getting one i would get one for my truck but they are expensive

 

MAG-Hytec

 

Thats the exact company i was looking at. Those are some good looking covers

 

how are the rear diffs on a expy any different than a f150 that would cause them to less reliable?

 

Just type expedition rear end into any search engine and thats the first thing that comes out i wouldnt know the technical.

 

I think the Expeditions all have 8.8 rears, even with the 5.4. I know my 2003 did. It's also independent rear suspension so it may have a different housing. I never had any trouble with mine and I live in a pretty hot state.

 

Late model ('03-up) Expeditions with 5.4L have a 9.75 IRS suspension, with the smaller engines having an 8.8. IRS. IRS can be problematic in some ways, especially when it comes to modifications. Ford's actually seems decent overall, but it's an added complication... especially for people that can't figure it out. Whatever problems they may have, I doubt it's due to heat.

Diff heat depends on load, speed and gear ratio. High load= high heat. High speed= higher heat. Lower ratios 4.10, 4.56:1, etc.) tend to run hotter than higher ratios (3.55, etc.). The choice of lubricant could change diff oil temp higher or lower by 10-15 degrees too. With just a few exceptions, there's very little to worry about tempwise on most vehicles unless you tow. Most stay well under 200 degrees. I don't know of any Ford trucks that have temp problems while not towing. Towing is another ball game. A max load on some trucks could mean 300 degree temps.

 

Well im de designated tow truck of the group so i do much of d work. Monday i brougt my cousins car from modesto to san diego and back up to fontana for my fathers car

 

Late model Super Dutys have a finned aluminum diff cover from the factory. It will fit earlier 10.5 and 10.25 Sterling rear axles. I have one on my 98 F-250 LD. About $40. Itasca may have a better price.