I will try to post a how to on removing a G80 carrier with ring and pinion gears from a 1500 GM truck. This is a complete teardown of a 10 bolt rear end for the GM trucks, let this thread be a guide for you. As always use common sense at all times, some of my methods may differ from yours. I am removing the factory G80 differential and 3.42 gears making way for an upgrade. The upgrade will follow in a separate install thread.
First off remove the spare tire from the underside of the truck and set it aside, this is just so you have more room underneath to get at things. Jack up the vehicle and support it on jackstands. Remove rear wheels and set aside.
Remove the bolts and brackets from the differential cover, leaving a few in until the bulk of the oil has drained out. Place a suitable drain pan underneath to catch the oil.
While the cover is loose and oil is draining, remove the brake drums. Each drum has two holes that a 10mm bolt can be threaded into to jack the drum off of the spigot of the axle. Remove and set aside.
Mark the yoke and driveshaft then remove the u joint straps and tie the driveshaft out of the way. Or you can remove it completely from the trans, but then you have transmission fluid to deal with.
The fluid should be about drained out so remove the diff cover completely exposing the carrier. Rotate the pinion until you see the cross pin securing bolt, remove it with an 8mm wrench or socket.
Now that the bolt it removed slide the cross pin out of the carrier, careful it's slippery.
Now rotate the pinion again exposing the center access hole. Now go to one axle and shove it in, it will only move about 3/8 of an inch or so. You will have to do this for each axle, I do one at a time.
Now look in and you will see the axle retaining clips. Using a sharp hook tool and or a magnet, slide the clips off of the end of the axles.
The axles can now be pulled and set aside, if you are re-using the axle seals and bearings do this gently so you don't damage anything.
Remove the pinion nut, you can use an impact if you have one or you can use a pipe wrench and a 32mm socket and breaker bar or long ratchet. It's gonna be tight so rest the handle of the pipe wrench against the floor. Loosen the pinion nut but leave it on by a few threads for now.
Mark and remove the two bearing caps, mark these well. You want to install them exactly how the came off.
Note the shims that I am pointing at in this pic. You want to make sure when the carrier is removed that these shims get measured. This will give you a starting point for setting up the new carrier. Take care in keeping them straight and knowing which side was driver or passenger side.
You are ready to remove the carrier, it will not fall out and will need a little help getting it free from the housing. So place a 19mm wrench on one of the ring gear bolts and wedge it against the diff housing while turning the pinion. This is easier with two people but one person can do it. Just be careful and don't get any smashed fingers. One trick is to loosely install the bearing caps so it doesn't fall out in your lap.
Once the carrier is about 1/2 inch or so out of the seat you can stick a hammer handle up inside the center section and help pry it out of the diff housing.
Now you are ready to remove the pinion gear. Using a brass punch and hammer. Rap on the pinion from the yoke side, this will loosen up the yoke and begin to slide the outer pinion bearing off the pinion. Remove the yoke and continue to drive the pinion out of the housing, I like to lay a rag in the diff housing to catch it. I also hold the end of the pinion and punch with one hand while tapping the pinion free.
It's time to remove the outer pinion bearing, race and seal. You can do this in one shot with a hammer and punch. There are slots in the housing for doing this, tap one side then the other gradually working the race, bearing and seal free from the housing. When it is free it will go flying across the floor.
Note the slot, there is another just opposite of this one:
See, shit will fly.
Now come around to the forward end of the housing and drive the inner race out using the same technique as described for the outer pinion bearing, race and seal.
Measure your carrier shims and mark down the thickness, this will be important later for setup. You can use a good slide caliper to do this, I just had my 1 inch mic laying around.
You have parts to clean now.
** Axle bearing and axle seal removal**
Now the only things left to get out of the housing are the axle bearings and axle seals. First using a small chisel or punch fold down the upper portion of the axle seal, this will make it easier to remove. Just be careful not to knick the axle tube while doing this, you just need to tap the chisel. No brute force needed here.
Using a long punch or prybar pry the seal out of the housing. Place the tip of the punch up inside the seal and press hard on the handle of the punch, the seal will rotate out of the housing.
For axle bearing removal you will need a good slide hammer with a puller on it. Insert the jaws into the bearing and give the slide several pulls. They don't come out easy and they are tough almost to the end.
Removed bearings and seals:
Bare housing is now ready to be cleaned and re-assembled.
First off remove the spare tire from the underside of the truck and set it aside, this is just so you have more room underneath to get at things. Jack up the vehicle and support it on jackstands. Remove rear wheels and set aside.
Remove the bolts and brackets from the differential cover, leaving a few in until the bulk of the oil has drained out. Place a suitable drain pan underneath to catch the oil.
While the cover is loose and oil is draining, remove the brake drums. Each drum has two holes that a 10mm bolt can be threaded into to jack the drum off of the spigot of the axle. Remove and set aside.
Mark the yoke and driveshaft then remove the u joint straps and tie the driveshaft out of the way. Or you can remove it completely from the trans, but then you have transmission fluid to deal with.
The fluid should be about drained out so remove the diff cover completely exposing the carrier. Rotate the pinion until you see the cross pin securing bolt, remove it with an 8mm wrench or socket.
Now that the bolt it removed slide the cross pin out of the carrier, careful it's slippery.
Now rotate the pinion again exposing the center access hole. Now go to one axle and shove it in, it will only move about 3/8 of an inch or so. You will have to do this for each axle, I do one at a time.
Now look in and you will see the axle retaining clips. Using a sharp hook tool and or a magnet, slide the clips off of the end of the axles.
The axles can now be pulled and set aside, if you are re-using the axle seals and bearings do this gently so you don't damage anything.
Remove the pinion nut, you can use an impact if you have one or you can use a pipe wrench and a 32mm socket and breaker bar or long ratchet. It's gonna be tight so rest the handle of the pipe wrench against the floor. Loosen the pinion nut but leave it on by a few threads for now.
Mark and remove the two bearing caps, mark these well. You want to install them exactly how the came off.
Note the shims that I am pointing at in this pic. You want to make sure when the carrier is removed that these shims get measured. This will give you a starting point for setting up the new carrier. Take care in keeping them straight and knowing which side was driver or passenger side.
You are ready to remove the carrier, it will not fall out and will need a little help getting it free from the housing. So place a 19mm wrench on one of the ring gear bolts and wedge it against the diff housing while turning the pinion. This is easier with two people but one person can do it. Just be careful and don't get any smashed fingers. One trick is to loosely install the bearing caps so it doesn't fall out in your lap.
Once the carrier is about 1/2 inch or so out of the seat you can stick a hammer handle up inside the center section and help pry it out of the diff housing.
Now you are ready to remove the pinion gear. Using a brass punch and hammer. Rap on the pinion from the yoke side, this will loosen up the yoke and begin to slide the outer pinion bearing off the pinion. Remove the yoke and continue to drive the pinion out of the housing, I like to lay a rag in the diff housing to catch it. I also hold the end of the pinion and punch with one hand while tapping the pinion free.
It's time to remove the outer pinion bearing, race and seal. You can do this in one shot with a hammer and punch. There are slots in the housing for doing this, tap one side then the other gradually working the race, bearing and seal free from the housing. When it is free it will go flying across the floor.

Note the slot, there is another just opposite of this one:
See, shit will fly.

Now come around to the forward end of the housing and drive the inner race out using the same technique as described for the outer pinion bearing, race and seal.
Measure your carrier shims and mark down the thickness, this will be important later for setup. You can use a good slide caliper to do this, I just had my 1 inch mic laying around.
You have parts to clean now.
** Axle bearing and axle seal removal**
Now the only things left to get out of the housing are the axle bearings and axle seals. First using a small chisel or punch fold down the upper portion of the axle seal, this will make it easier to remove. Just be careful not to knick the axle tube while doing this, you just need to tap the chisel. No brute force needed here.
Using a long punch or prybar pry the seal out of the housing. Place the tip of the punch up inside the seal and press hard on the handle of the punch, the seal will rotate out of the housing.
For axle bearing removal you will need a good slide hammer with a puller on it. Insert the jaws into the bearing and give the slide several pulls. They don't come out easy and they are tough almost to the end.
Removed bearings and seals:
Bare housing is now ready to be cleaned and re-assembled.
