The rabbit hole
Whenever you embark on a classic car project, you inevitably head down the rabbit hole. There will come a point where you say "Well since I'm in here, I might as well do ________ also." That sentence can get you into a lot of trouble.
I set out to redo the rear brakes. I've been having some e-brake issues, and I knew one of the slave cylinders in the rear brakes was old and needed replacement. I started down the rabbit hole by rebuilding both of the rear brakes completely. Even though I didn't need to refresh all of the parts, I justified doing it since I would be down there anyways. The complete rebuild would include:
- All new pads
- New OEM wheel cylinders
- New backplates
- New springs
- MiniSport Aluminum Finned brake drums
- Stainless steel lines
The Subframe Mounts
And then it happened... while I was down there tearing down the brakes, I noticed that the bushings for the subframe mounts were worn and cracked. This is where the fun really begins. Because I noticed the worn bushings I started poking around all the subframe mounts. I noticed that the 2 front mounts were missing 1 mounting bolt each (the lower one on both sides). They were just not there. Now that I saw that, I decided it was time to fully renew all of the subframe mounting hardware and bushings.
I went for the following:
- Poly bushings
- New Truunion bolts on both sides
- New subframe mounting kit with all new bolts/washers/nuts/etc
When I fully dismantled the subframe mounts, I had access to see why there were no bolts on the lower half of both front mounts. The bolts were sheared off, and the studs were still in the body. I was able to extract the driver's side stud without much difficulty, but the passenger side was a whole different story.
The extractor bit I used to try and remove the stud broke off inside the hole I drilled in the stud. This is actually bad, because the hardened extractor bit is made out of super-hard steel. This sent me down the path of trying to find a drill bit that could cut through the extractor bit. Eventually, after about a week of banging my head against a wall, I was finally able to break it with a combination of a diamond-coated Dremel bit, and many different cobalt, mason, and titanium drill bits of all sizes, stepping up and up in size until I was finally able to drill through it.
The downside of all this work is that my hole I was finally able to drill is angled 'slightly' upward, which means getting a bit when I mount the truunion mount to it will be challenging to say the least. I have yet to try this, since I am waiting for a new subframe. In part 2, I will have attempted this, and will report here.
On the subframe note, the holes that were there for the brackets had little-to-no-threads left, so I drilled new holes and had to tap larger threads. Because of this, I had to go up to an M10 bolt, which is massive. Because I was trying to do that, I ended up busting a nut that was welded onto the subframe. In addition, the diameter of the M10 bolts is too large, and I can't get a socket on 4 of the 8 bolts for the brackets. Taking all of this into account, I am ordering a new rear subframe, which should be here next week. Stay tuned for part 2 which will cover the removal of the current subframe, and the work of putting it all back togither.