How do you change a manual transmission in a 1988 Ford Mustang 5.0L LX 5 speed?
first, remove the shifter: from the driver's seat, unscrew the shift knob. pull straight up on the black trim surrounding the shifter, and the boot will come as well, remove from stick and set aside. destruction time: this isn't the friendliest way to get at the bolts, but it's effective and hidden when reassembled--you have to chip away at the console where it covers up the front two bolts holding down the shifter. don't destroy too much, or you'll knock out the retaining clip holes for the black trim. remove the four bolts holding the shifter to the transmission. pull up, keeping in mind that it will still be held in place by silicone sealer (gasket maker), so some tugging may be required.
to the underside: raise the whole car off of the ground by using four jackstands, a lift, etc.
remove the H-pipe. this is a pretty easy task if it hasn't been on long, or this will be the dealbreaker on the project. i find it helpful to take out the two oxygen sensors to gain access to the nuts holding the pipe to the headers--that's a 7/8" socket to remove them. get at the nuts on the headers from below with a lot of extensions and a universal joint, and, if available, an impact gun. there are two nuts per side. shift to the other end of the pipe and remove the four (total) nuts holding the h-pipe to the cat back system. use WD40 on the hangers for the pipe (located at the trans crossmember- they're two metal rods that stick foreward into a flying wing-looking holder. pull down on the pipe to clear the firewall while pulling back on the pipe to release it from the support--it takes some patience. remember that the h-pipe weighs like 35 pounds, so be careful when it lets go.
remove the driveshaft: there are four 12mm 12 point bolts that hold the driveshaft to the differential housing. they're accessed most easily when the driveshaft is rotated around until you can get at them, or by using a wrench rather than a socket. it'll drop when it's disconnected at the back, so watch again. once unbolted, it will slide right out of the transmission--use steady force and it'll come. another 25-30lb part...
remove the speedometer housing: this is located by the transmission crossmember--you'll see the cable leading towards an adapter looking thing that has an electrical connector on it. the whole thing pulls out when the 10mm retaining bolt and clamp are removed--it's self explanitory.
pull the reverse and neutral safety switch wiring plugs off--you'll see them. it could just be one, though... i haven't done this in three years... nothing's hidden, though.
GET A PAN HANDY
remove the two bolts holding the transmission crossmember to the car. they're long bolts that are mounted way to the outboard.... the transmission can be removed with the crossmember still attatched.
two notes of warning: at this point, the drivetrain will shift down. after all, you've just taken away the rear support for it. don't worry about it, as it'll only be a couple inches and won't hurt anything. other note: the trans has close to three quarts of fluid in it. you've just tipped it. i think you can see where this is going. that pan's handy, right?
remove the four bolts holding the transmission to the bellhousing: big bolts, no problem. the trans won't drop out or fall off because the end of the input shaft is still in the clutch and flywheel. if you're strong, just lift and wiggle it out onto your chest (this is what I do--i lie underneath it) but if you're unsure about whether or not you'd like 70lbs or so of transmission on you, a trans jack or an assistant might be a wise choice.
the first time i did this, it took around two hours. now, i can take it out, take apart/reassemble the case (fixing whatever i'd done wrong) and reinstall it in less than that, total. it's very straightforward.
install notes: remember to use new silicone sealer on the shifter--just go around the perimeter pretty heavily. from the top is the best place to add fluid--just pour it in the shifter hole. if you've got it out, make sure to flush out the case and replace all fluid anyway, as a precaution. it takes around three quarts of ATF fluid, and buying synthetic stuff does make it work better. brush some antiseize onto the header bolts and O2 sensor bases to make taking them out in the future easier.
let me know if you need directions for taking off the bellhousing, too.