In the last progress report on Project CJ3A, we removed a broken stud in the front-axle steering knuckle. After tearing down the rest of axle, we found yet another broken stud. This time it was one of the bolts holding the differential housing cover plate on.
The gasket sealing the cover plate to the axle housing was leaking like a sieve before we tore down the old Jeep. After removing the cover plate, the reason was clear. Someone had removed it before and used silicone sealant to form a new gasket. That had deteriorated. Making matters worse was the broken stud, which meant the plate couldn’t be snugged up to the housing properly.
After scraping the remaining silicone off the axle mounting surface, there was still a lot of rust remaining. In order to get the plate to seal again, all that corrosion and crud needed to come off too. Using a sanding block and 400-grit paper, we sanded the surface until we had it shiny and smooth again.
But there was yet another problem to deal with. At some point the axle must have struck something solid, and some metal from the housing was protruding above the mounting surface, which would hold the cover plate away from the mounting surface at that spot. Using a fine-tooth hand file, we attacked that protruding lip and worked it down until it was smooth with the mounting surface.
But there was still the broken stud to deal with. In our last instalment, we welded a nut onto the protruding portion of that broken bolt in order to twist it out. But this time, the stud was broken flush with the housing, so that tactic wouldn’t work here.
Instead, we pulled the set of stud extractors, commonly referred to as easy outs, from our tool box.
The first step in removing a broken bolt with this type of tool is getting a relatively smooth surface to work with. That meant sanding the broken, jagged end of the bolt down to a flat surface — or as flat as we could get this one. Part of it was broken below the level of the mounting surface.
To smoothen it out, we put an 80-grit sanding pad on a dual-action sander and carefully worked protruding chunk until it was smooth with the housing surface. Then, using a centre punch, we marked a starting point for a drill bit as close to the centre of the broken bolt as we could eyeball it. (Getting that right is important to prevent damage to the threads in the axle housing).
Then, we drilled a pilot hole right through the centre of the broken stud. Next, we selected the widest drill bit we thought we could safely use without drilling outside the bolt and damaging the hole’s threads.
More from the Grainews website: How to remove a broken stud
The broken stud was in a threaded hole that went right through the axle housing, so we were able to apply penetrating fluid from both ends to help free it up.
Now it was time for the extractor. Drilling the largest hole feasible allowed us to select the thickest, and therefore strongest, extractor that would fit. This part calls for a bit of a tender touch. The extractors are made from hardened steel, but they’re still relatively thin. They can, and will, break if you twist too hard. Trust me on this. I speak from experience. If you do break one off in place, you’ll end up with a broken hardened-steel stud inside a broken mild-steel stud stuck in a mild-steel housing. Drilling that out is something you may want to trust to a machine shop, which means added cost and delay.
Even after applying a little heat, this stud wouldn’t budge. Rather than press our luck and risk breaking the extractor, we opted to simply leave things as they were for a while. We continued applying penetrating fluid over several hours and then let the piece sit overnight. Patience is a virtue with this job.
The next day, we applied more heat and more fluid. Eventually, the heat and fluid did their jobs and the stud turned free with a gentle twist. Then, we were able to easily back it out.
With a new gasket in place and the backing plate back on, the axle is now ready to be mounted back on the chassis and fully reassembled. †