9" diff install

Pretty simple job.

1. Jack up car and unbolt driveshaft from pinion yoke. Probably best to leave the slip yoke in the tranny, cuz if you pull it out the ATF or gear lube will leak out the hole.
2. Remove wheels. Remove drums. They pull right off, but they may be stuck on the shoes, which you'll know if you pull on them and they pull out but seem to spring back into place. If so, you need to adjust the starwheel down on the adjuster, through the little slot in the bottom of the backing plate.
3. Unscrew the four nuts on the bearing retainer plate. There's a hole in the axle flange that you can rotate to access these nuts, one at a time. The axle shaft should pull out. If it doesn't, put the brake drum back on, but "inside out," and thread three or four lugnuts back on the studs a couple turns, so you can use the drum like a slide hammer. Make a note of which axle shaft is longer; obviously you have to reassemble with the longer one back where it belongs.
4. Might-as-well time: might as well replace your bearings and seals now. The bearings require a machine shop to remove the old and install the new. The seals require a puller hat you can rent at the Auto Zone or Kragens, and a large socket or a piece of pipe or best of all a seal driver to install the new.
5. Unscrew all the nuts from the studs holding the chunk to the axle housing. If yours has never been apart it's going to have copper crush washers on each stud. They're going to make it hard to get the chunk free of the housing. Don't worry about replacing them on the install of the new piece; nobody ever does. If yours HAS been apart before, most likely it has ATF silicone all over the mounting surface, which also is going to make it hard to separate the chunk and the housing. So you're most likely going to need a dead blow BFH (big f**kin hammer), or a 2 x 4 and a plain old BFH, to get things moving. Don't worry, there's nothing holding the parts together other than stubbornness (and washers and ATV). So whack away; think of your pointy haired boss it that helps. And make sure you've got a drain pan under the chunk, because some nasty gear lube is going to come pouring out as soon as you open a gap.

Just one point. Make sure you actually have a 9 inch rear end under there. The factory choice was an 8 inch unless the car came with the Hipo 289 engine.

Thanks that will help me out alot. When I bolt the third member back on to the axle housing, should I use a gasket or just use silicon?

Just use silicone. And use the room temperature vulcanizing silicone (RTV), not automatic transmission fluid (ATF) silicone or all terrain vehicle (ATV) silicone. Those kinds don't exist.

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