Thread Repair

Thread Repair Kits for Your Vehicle

There are numerous ways that threads can become damaged: over-tightening a bolt, trying to force the wrong bolt through a hole or fighting with rusted parts. Any of these situations can throw a wrench into your DIY plans. Fortunately, thread repair kits take care of this frustrating issue quickly. Dies help you form external threads on rods, bolts and connectors, while taps are designed to redefine worn internal threads and cut new threads. The best thread repairs for cars and trucks depend on the type of thread affected and where it's located.

Understanding Spark Plug Inserts

If a spark plug thread hole is loose after years of use, a form tap, or chaser, can clean the opening and give spark plugs a firm grip. Chasers don't actually cut metal; they use pressure to push it into the correct shape. If over-tightening or incorrect bolt choice leads to a completely-stripped hole, taps may not be enough to guarantee a solid hold. That's when you need to install an insert instead.

How Your Inserts Work

Inserts have threads on both the inside and outside surfaces. They're a permanent fix, installing under pressure within a larger hole to accommodate the original bolt size required by the manufacturer. When the job is done correctly, inserts can stand up to OEM torque and pressure requirements in high-stress locations. The insert-installation process isn't complex as long as you have the right tools: a correctly-sized drill and drill bit, tap, insert, installer tool, hammer and punch.

Types of Form Taps

Taps come in several types: plug, taper and bottoming styles. Taper taps are great for starting through-holes since they're easy to introduce and follow existing threads well. Blind holes require a different approach. You can opt for plug taps, which are barely tapered, or start with a bottoming tap to cut a guide first before switching to the plug tap. Bottoming taps have around three to four tapered threads, while plug taps only have one.

Your Source for Thread Repair Parts

External threads can be trickier. To maintain structural integrity, you can't use a die to cut threads smaller than before. You can only recut to the same diameter. This may be OK for areas where load isn't a huge issue, but when bolts or rods are required to stand up to heavy stress, it's often best to replace the part. Fortunately, at AutoZone finding OEM replacement parts is easy, and we give you the best prices on thread repairs solutions.

Get Help From Our Experts

When taking care of thread repair yourself, take special care to introduce the tap at the correct angle, usually at 90 degrees to the part. Deciding whether to DIY or call our AutoZone pros often depends on your previous experience and what kind of stress the part has to stand up to. At AutoZone, we actively encourage DIY solutions since we know how important the relationship is between owners and their cars. However, if you don't feel comfortable re-threading high-risk structural components such as control arms or an engine block, don't hesitate to give us a call right away or search for thread repairs near me at our location page.