Resurrecting an 8 inch rear

The first thing my son said when I brought home his ’67 was that we need to put a bigger motor in it. Our children do become us. I did the same thing and ended up with no engine in the car for many years. I am going to do my best to help him avoid that. To that end, rather than put more work in the front or rear brakes that are on the car, I am working on putting a V8 5 lug setup on it. For the rear, that means recovering an old 8 inch rear end Randy had growing into the earth.

As my local Mustang restoration expert, I asked Randy if he knew of any old 67+ 8 inch rear ends anyone might be selling. He said he had one in the back that he would let go. First look I was thinking its already half way in the earth, just let it finish it’s descent and be done with it. I was hoping for something mostly usable just to put in the car without rebuilding. After some searching, I couldn’t find a local solution, so I went with the graveyard rear. He said if I can make it work, give him $100. If it wouldn’t work, keep the $100 and scrap it.

It looked pretty bad, but really, it was just dirt, surface rust, and maybe a few spiders. I expected all of the attachments were trash, including the brakes, lines and cables. It was also missing the vent nipple, allowing the grease to protect a part of one of the tubes. One drum was stuck on, which required some hammer action to remove it, the other already missing.

My plan at this point is to tear it all down and see what the parts list looks like. I figure I will need all new brakes and parking brake cables. I also want to replace the bearings, shaft axle seal, and lug studs while its apart. Cheap parts while its apart. Expensive to fix later if the originals have any hidden issues. Plus one of the lugs was already gone, with some of the others looking a little rough.

To get started, I would like more than a visual inspection to see what I brought home. The original ID tag is still attached, so a little clean up and it’s readable.

Looks like a ’68 8 inch with a 2.79 open gear. Pretty common rear end. There goes any dreams of something fancy. Oh well. The plan at this point is to not touch the carrier other than pulling it out, cleaning the outside, and setting it aside until it’s time to assemble again. That can be a future project for my son if he wants to spend the $1,000 for dual traction and better gearing for the future 5 speed.

Moving on, the brakes were trash, but they look just like what I have in my 67. One minor difference I didn’t notice until I was rebuilding was the lack of an auto brake adjuster. Everything else is there. I wonder if this is just a poor brake job by someone, or if something else is going on.

After about half an hour of taking everything off that will come off, I am left with a center section and some oil to recycle. Axles look good, just needing the bearings and studs pressed off and some attention with the wire wheel.

The differential is set aside for some attention on the external surface once I get the housing cleaned off. The plan there is to use a heated pressure washer to get the oil and chunks off and see if I need to take the wire wheel to it or if I can just paint it and move on. I am hoping to just brush the differential and leave it, but the rust may be taking over. That will make itself evident soon enough.

I thought I would send the backing plates off to get blasted and powder coated. Then I thought I would save the money and just blast and paint them myself. Looking at how they started, I was pretty surprised just how well they cleaned up.

This time around, I decided to load the backing plates before putting them on the rear end. I am blocked by needing to take the housing in to get cleaned, so I am doing what I can for assembly in the mean time. I saw pictures of someone taking off the whole backing plate, which gave me the idea of building them that way. This is my first time going this route, so I hope I don’t regret it and have to take things apart. It’s definitely easier to work on brakes on the bench rather than sitting on the garage floor.

I took the axles in to my local automotive machine shop to press off the studs and bearings. Rather than putting the new parts on right away, I picked them up and cleaned up the axles, plus blasted and painted the retaining plate. Once cleaned and shiny, I took the axles back to the machine shop to have the new studs pressed in and the new bearings installed.

Next was to clean up the housing itself. Randy has a heated pressure washer, so I dropped it off with him to have one of the guys cook the grease off. I did some sand blasting on it out in the driveway with the pot blaster, then rattle canned some primer, and painted it.

Painted, then test fitting the axles. Not shown, I hammered in the seals in the tubes by this point. I also got a new carrier gasket and bolted it in. It fits great backwards too, so something to pay attention to. Not that I have any experience with that.

Then taking the axles back out and putting on the loaded backing plates. Order is gasket, backing plate, axle and axle retaining plate, then bolt it all together. I also cleaned up and painted the original T bolts because I love blasting parts.

Finally, I put on the vent nipple, junction block, and brake lines. Calling it complete and ready to install in the car. I also need to add the oil, but I want to do that when it’s under the car and flat on the ground so I don’t have issues moving it around.

Now I just need to get those 50+ year old leaf springs off the car so I can swap out the rear ends. Hopefully it won’t require too much cutting to make it happen. To localize problems, I plan on putting in the rear and bleeding the brakes to check for leaks before doing the front. The front swap to disc is going to require a new master, and some new lines to the distribution block possibly, so making sure the back is good before adding that to the mix should make my life simpler, though will require bleeding twice.

Ready for installation

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