Removing a broken manifold stud becomes a very expensive repair if the cylinder head gets damaged in the process. Conventional use of a drill and screw extractor often ruins an aluminum cylinder head. At the 2016 SEMA Show, OTC Tools demonstrated the use of the OTC 6982PMC stud removal tool and a drill guide kit, the cost-effective approach that can save time and considerable shop labor—or quickly solve a major problem for the DIY mechanic.
OTC Tools is widely recognized among professional service personnel and serious DIY mechanics. Niche tools reflect a close relationship between OTC Tools engineers and real world shop environments. The OTC Tools catalog is full of well-crafted solutions for field troubleshooting and resolving situations like broken studs.
Traditional tools like OTC’s safe hub pullers are well known among technicians. 4WD Mechanix Magazine has tested the popular OTC 7394 puller, click here for the how-to video on its use. We have also tested and performed diagnostics with the official Chrysler Miller/SPX DRBIII scan tool by OTC, click to see our speedometer calibration on the magazine’s 2005 Dodge Ram 3500 4×4. At the 2013 AAPEX Show, the magazine filmed OTC demonstrations of niche specialty tools. Included was the unique solution for removing the notorious broken spark plugs from a Ford Triton engine—with the cylinder head in place. At right is a unique, niche pair of tools for removing late Dodge Ram unit bearing hubs without damaging the steering knuckle. Click these links to see our tests and HD video coverage of these OTC tools!
This kind of quick problem solving is cost-effective, these tools pay for themselves quickly. The OTC drill alignment tool and collars provide the best approach for safely drilling a broken bolt or stud before extraction. If the stud or bolt breaks below the surface, a screw extractor and extreme care can remove the drilled bolt or stud shank. When drilling a bolt or stud shank, use the largest diameter drill size that will stay safely within the margins of the casting threads. This will relieve bolt or stud tension at the threads and requires less extractor force. Do not damage the casting’s threads!
The OTC Tools solution for drilling true, on-center holes in a broken bolt or stud can be seen at left. The tool aligns with the stud or bolt centerline, and a drill guide fits into the centering hole of the guide. On aluminum heads, there is no room for error. For aluminum or cast iron cylinder heads, the centering tool eliminates the tendency for the drill bit to creep off-center. Use quality carbide bits when drilling a broken stud or bolt, do not break the drill!
The OTC 6982 PMC is a niche tool that pays for itself. If the stud or bolt breaks with a small portion still protruding, this tool with its collets and compression sleeve will lock down on the extended piece and enable turning out the broken shank. Soak the stud or bolt shank with penetrant before applying pressure. In most cases, the bolt or stud will unscrew without breaking again. Certainly a tool worth having when working around cylinder heads exposed to higher temperatures and corrosion.
At left is the safely removed stud. If the threads are damaged, most shops step up to the closest size. (Examples: For a 6mm broken stud, increase to a 7mm replacement; for a 5/16″ broken stud, replace with a 3/8″ size and so forth.) There are often step size manifold studs that provide the same outer stud size as the original…The OTC 6982 PMC and the stud drilling guide kit can solve a variety of stud or bolt breakage issues. In-the-chassis repairs save major labor costs. Unless the head(s) need service, a repair in the chassis is always the first approach.