The easiest solution is to Heli-coil the hole if it isn't severely damaged. You would get the proper sized kit that includes the drill bit, the special tap and the insert and install tool. The process is simple. The hole is drilled with the bit, then you tap the threads and install the insert. The tang on the insert gets snapped off and now you have new threads in the original size to use. You want all four bolts, then can warp and leak at the base even with all four so trying to use only three is just asking for trouble. Many parts stores have the master kits as loaner tools. You "buy" the kit and install the inserts and when you return the kit in good shape, they give you back the money. You end up paying only for the inserts you actually use instead of having the rest of the kit to store.
This is a video showing the full process in a new hole, in your case you would use the damaged hole and just drill it out.
https://www.youtube.com/watch?v=xigq7aPpff0
Feb 10, 2025 at 11:10 AM
