how hard is it to remove and install a new third member one like this http://cgi.ebay.com/ebaymotors/FORD...ptZMotorsQ5fCarQ5fTruckQ5fPartsQ5fAccessories
Not hard, I did it recently. While you have the axles out, you might consider getting some new bearings pressed on to go with all the other new stuff.
Don't forget the seals on the end of the axles along with the bearings...A little tip..Before putting one axle back in, refill the gear oil by pouring into the axle tube....Just jack the car a little higher on that side....Much easier than doing it from the fill plug
I had absolutely no prior experience and I took mine out, installed a PowerTrax locker in my open diff. third member and reinstalled it with a little help from my Dad just because I can't lift heavy stuff anymore. Taking it out was pretty easy the hardest part is if it has never been out before there are copper washers behind each nut and they are a B1TCH to get out and you can't remove the centerchunk/third member without getting all those copper washer off the studs. We picked them out with a pocket knife. Do what everyone else is suggesting and replace the axle seals when you put the axles back in and check your bearings and either grease them good or replace them.
Use the money you would pay to have it installed to buy a set of Ford shop manuals for your car. Read the procedure and I think you'll decide you can do it. Then you'll have the shop manuals for your next project.
Slide axles out Unbolt 3rd member and drain Replace bearings/seals(if needed) Install new 3rd member Install one axle Fill it up with gear oil Install other axle DONE It's really easy. The hard part is setting up the 3rd member, but that one is all set up and ready to run. You can also install drain/fill plugs while your at it. Makes things much easier later on. You can get the plugs for free at a junkyard, I like the OEM type because all you need is a 1/2" ratchet or breaker bar to remove them. Then just drill and Tap the holes.
For the copper washers, you can pry them up at an angle with a small chisel or screwdriver, and then cut them with a side-cutter pliers. Then peel them off with a needle-nose pliers. They will try your patience a bit, but don't be afraid to destroy them. You won't be replacing them. Rather than a gasket, I used ultra-black Permatex silicone gasket maker.
That is pretty much what I did, most of them got destroyed and I used a gasket and black permatex when I put the center chunk back and unbelievably I am still leak free.
