All of the info is in various places, but I thought I would combine it and put it all in one post for those needed to reseal their diff. It isn't a hard project, just a bit time consuming. Here is a lot of the information I found:
-Lube is 1.4L (1.48 quarts) of 75W-140 full synthetic. Pick whatever brand you want, but I used Mobile 1 ($16/quart). I didn't use any friction modifier, based on this from their site:
Mobil 1 Synthetic Gear Lube 75W-140 LS contains special friction modifiers designed for limited slip-type differentials. In most applications, the addition of special LS (limited slip) additives is not required. For axles requiring the highest level of limited-slip performance, OEM specific LS additives can be added to this fluid.
(http://www.mobiloil.com/USA-English...il_1_Fully_Synthetic_Gear_Lube_75W-140LS.aspx)
I put in (not intentionally - didn't have the spec at the time) about 1.75 quarts before it came pouring back out. I left it in there and didn't have any come out the vent or leak around the seals. The manual says to fill 1/4 to 9/16 below the fill hole.
-The two most popular sealants are the Ford (I've seen TA-29 and TA-31, not sure which is better) and Permatex Ultra Grey. The Ultra Grey is easier to get and cheaper, which is what I went with. The packaging says it's good into the 600 degree range, but the web site says 500, so hard to say which. Either way, the high torque aspect is the more important thing in this case. The factory stuff I pulled out was black. Allow the sealant 24 hours to cure with no lube in the diff (see the pic below - I left it this way so nothing would even drip on it).
-A great web site for doing the whole thing is here: http://www.lx.net/jlynch/pumpkin.htm - The instructions are for a 99, but the only thing different for the 03 was removing the lower IRS brace, which is very easy (see pic below of the few threads handing out to keep the rest of the IRS in place). I checked his torque specs for the 03, and they are all the same. I put threadlock on the driveshaft bolts per the Ford service manual, and not antiseize as mentioned in the link above.
-Autozone will loan you a 250ft/lb. torque wrench, the pullers, and a 36mm socket. Checker does this as well. They just charge and refund when you return them. Part numbers for the Autozone pullers are on the site above.
A few things to keep in mind prior to doing this is that it would be a perfect time to replace your fuel filter because it's so easy to get at, and also a perfect time to upgrade the IRS bushings if you want. The stiffer bushings have the potential to increase noise and vibration, but will likely reduce driveline clunk and wheel hop, so your choice. You are supposed to replace the halfshaft retainers (the nuts you torque to 240ft/lbs.) but I didn't. If you want to, you'll probably have to order them in, so keep that in mind.
The whole thing is pretty easy (LT header installation and the EGR tube come to mind for more difficult projects). I don't rush on my Cobra projects, so it took me about 3 hours to get it out, cleaned, and sealed, and 3 to put it back in. Just be careful of those 19mm wrenches - my dad broke off one of his teeth when tightening a rear diff mount bolt!
I didn't get a picture of that...
-Lube is 1.4L (1.48 quarts) of 75W-140 full synthetic. Pick whatever brand you want, but I used Mobile 1 ($16/quart). I didn't use any friction modifier, based on this from their site:
Mobil 1 Synthetic Gear Lube 75W-140 LS contains special friction modifiers designed for limited slip-type differentials. In most applications, the addition of special LS (limited slip) additives is not required. For axles requiring the highest level of limited-slip performance, OEM specific LS additives can be added to this fluid.
(http://www.mobiloil.com/USA-English...il_1_Fully_Synthetic_Gear_Lube_75W-140LS.aspx)
I put in (not intentionally - didn't have the spec at the time) about 1.75 quarts before it came pouring back out. I left it in there and didn't have any come out the vent or leak around the seals. The manual says to fill 1/4 to 9/16 below the fill hole.
-The two most popular sealants are the Ford (I've seen TA-29 and TA-31, not sure which is better) and Permatex Ultra Grey. The Ultra Grey is easier to get and cheaper, which is what I went with. The packaging says it's good into the 600 degree range, but the web site says 500, so hard to say which. Either way, the high torque aspect is the more important thing in this case. The factory stuff I pulled out was black. Allow the sealant 24 hours to cure with no lube in the diff (see the pic below - I left it this way so nothing would even drip on it).
-A great web site for doing the whole thing is here: http://www.lx.net/jlynch/pumpkin.htm - The instructions are for a 99, but the only thing different for the 03 was removing the lower IRS brace, which is very easy (see pic below of the few threads handing out to keep the rest of the IRS in place). I checked his torque specs for the 03, and they are all the same. I put threadlock on the driveshaft bolts per the Ford service manual, and not antiseize as mentioned in the link above.
-Autozone will loan you a 250ft/lb. torque wrench, the pullers, and a 36mm socket. Checker does this as well. They just charge and refund when you return them. Part numbers for the Autozone pullers are on the site above.
A few things to keep in mind prior to doing this is that it would be a perfect time to replace your fuel filter because it's so easy to get at, and also a perfect time to upgrade the IRS bushings if you want. The stiffer bushings have the potential to increase noise and vibration, but will likely reduce driveline clunk and wheel hop, so your choice. You are supposed to replace the halfshaft retainers (the nuts you torque to 240ft/lbs.) but I didn't. If you want to, you'll probably have to order them in, so keep that in mind.
The whole thing is pretty easy (LT header installation and the EGR tube come to mind for more difficult projects). I don't rush on my Cobra projects, so it took me about 3 hours to get it out, cleaned, and sealed, and 3 to put it back in. Just be careful of those 19mm wrenches - my dad broke off one of his teeth when tightening a rear diff mount bolt!
I didn't get a picture of that...
