Threads Stripped? Time-Sert is the Best Fix
By Hib Halverson
If you’re a regular DIY working on Cadillac Vs, at one time or another you’ve probably stripped the threads out of a bolt hole or maybe someone else stripped threads out of a hole and you ended-up having to fix the problem.
Damaged or destroyed threaded holes have been a problem for DIYs as long as there have been cars for us to work on, but they’ve become more common in the last twenty years or so with the widespread use of aluminum in Cadillac powertrain, suspension and structural parts. Threads in aluminum are rolled for greater strength, but they can be easily be cross-threaded or, if a fastener is over-torqued, pulled out.
Some people think of a wire spring thread insert, such as “Heli-Coil” when they need to repair, say…a stripped exhaust manifold bolt hole in an LS V8 cylinder head. Studies by General Motors Global Propulsion Systems proved that for thread repairs, the Time Fastener Company’s “Time-Sert” is superior to spring-type inserts, especially in high strength applications. Time-Sert Thread Repair Kits create a new and stronger threaded hole which matches the original thread size allowing the original fastener to be used. Using one of these kits, you can easily repair damaged threads in aluminum and cast iron.
Key features making Time-Sert a better thread repair are: 1) It is a solid bushing insert which completely fills a tapped hole making it more reliable and durable than other products, especially when high stress and vibration are present. 2) It has rolled threads, matching those in aluminum engine parts and other components such as transmission cases, suspension cradles and a Corvette’s aluminum frame. 3) A Time-Sert is thin-walled due to its synchronized or “timed” internal and external threads, so it can be installed where space is limited. The timed threads inspired the brand name. 4) It has a flange at the top which positively positions the insert. It cannot move 5) The bottom few internal threads are cold-rolled during the installation process which expands the external threads into the base material, locking the insert into place. A Tiime-Sert installs easily allowing full load use of the threads. They are reliable even at the highest engine temperatures.
Time-Sert Thread Repair Kits include a drill, to enlarge the damaged hole to the next larger size; a counter boring tool, to cut the top of the hole for the insert’s flange; a tap to thread that hole for the insert and the installation tool, which locks the Time-Sert in place.
Time-Serts are approved by a number of automotive manufactures including General Motors which made Time-Sert Master Kits an “essential tool” for all Cadillac dealers. Time Fastener has Thread Repair Kits available in wide variety of metric sizes. The company also has a line of thread repair products for holes which have been repaired with other thread repair methods which have failed. Called “Big-Sert”, this product can repair a faulty installation most any other type of insert. It can also be used in a pre-emptive manner to add a thick-wall steel insert capable sustaining heavy loads to a hole in an aluminum part.
Use of a Time-Sert or Big-Sert kit is easy and requires no special tools other than either a tap wrench or a set of eight-point sockets to drive the tools by hand. First, you hand drill the damaged hole out to the next larger size. Then, you counterbore the top of the now-larger hole. Next, you tap the hole for the Time-Sert. Lastly, you use the Time-Sert installation tool to thread the insert into the hole and lock it in place. Typically, you can install a Time-Sert in 10-15 minutes. Additionally, in some cases a part can be “Time-Serted” without removal.
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Another common use of Time-Serts is to repair spark plug holes in aluminum cylinder heads and Time Fastener makes special insert kits for that purpose. Time-Serts for spark plug holes are specialized inserts that are silver-plated for use with taper seat plugs. A special thread locking compound must be used on the threads of a Time-Sert spark plug thread insert. Time-Sert Spark Plug Repair Kits are designed for use in heads installed on engines. Cylinder head removal is usually not necessary.
Over the last 25 years of so, I have used Time-Sert kits of various sizes, both SAE and metric, to repair holes. A couple of years ago, I salvaged an expensive, custom-built, 850 Holley carburetor by fixing stripped holes in the Holley’s main body with Time-Serts. Back in the early ’00s, I had the tail housing off the ZF S6-40 six-speed manual transmission in a ’95 Corvette. One of the bolt holes in the main case stripped. Again, Time-Sert saved my butt, big time, as I was able to insert the hole with the trans still in the car. Earlier this month, while working on our “shop truck”, I pulled the threads out of one of the holes in the A/C compressor mounting bracket. Yet again, a Time-Sert quickly fixed the problem. I’ve, also, used Time-Sert preemptively. A number of years ago, I built an aluminum-head Big-Block Chevy “project engine”. I knew we’d be changing intake manifolds a lot, so I put Time-Serts in all the intake manifold bolt holes.
At the Cadillac V-Net project shop, we keep metric Time-Sert Kits on hand in many common sizes because, we never know when we’ll pull the threads out of a hole. Having Time-Sert kits available, allows us to put the part back in service as soon as possible. Time after time, Time-Sert has solved problems for me quickly and easily. I refuse to consider any other thread repair product.
For more information, see the Time-Sert web site or call Time Fastener Company, Inc. at 800-423-4070.