Working With the Grizzly 660 Series Equipment
If you own one of these machines and something needs adjusting, you need the service documentation. The 660 Grizzly Service Manual covers the mechanical setup, electrical troubleshooting, and maintenance intervals for the 660 series lathes and drill presses. Most people run into issues because they skip the manual entirely and guess at adjustments. That usually leads to wasted time and worn parts. I had a G667Z drill press where the quill would lock up after about six months of use. The manual had the torque specs for the sleeve bearings and the spring tension adjustment. Without it, I was just grinding on it and hoping. Found out the set screws were overtightened and distorting the bushing. Proper spec brings it back to smooth travel in maybe twenty minutes.
Locating Your 660 Grizzly Service Manual
Grizzly provides documentation through their website. Go to grizzly.com and search the model number. The 660 series includes several variants like the G667, G667Z, G668, and G668Z. Each has its own manual PDF. Some older units might not have digitized versions available directly. If you cannot find it online, contact Grizzly support with your serial number. They usually email a PDF within a day or two. I have also seen third-party sellers on eBay listing scanned copies of older manuals, but those can be low quality and hard to read. Sticking with the official source is better for clarity.
What the Manual Actually Covers
The service manual is not just a parts list. It includes exploded diagrams, torque specifications, adjustment procedures, and sometimes troubleshooting guides for common electrical problems. For the 660 series, expect sections on spindle alignment, gear box maintenance, motor replacement, and brake adjustment if your model has one. The electrical section is particularly important. These machines typically run on 115V or 230V single phase. Wiring diagrams in the manual show you the proper connections for the reverse switch, overload protection, and speed selector. Getting this wrong can damage the motor or create a fire hazard. I once saw someone wire a G668 wrong because they assumed the terminal layout was standard. It was not. The manual prevented that kind of mistake.
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Adjustment Procedures You Will Use
The most common maintenance task is quill spring tension adjustment. Over time the spring compresses and loses tension, which makes the quill float instead of staying where you set it. The manual specifies the correct free height and installed height for the spring. Use a caliper and compare. Most people just replace the spring without checking, but sometimes cleaning and relubricating the quill mechanism fixes the problem. Another frequent adjustment is chuck alignment. The manual walks you through checking runout with a dial indicator and making small shims if needed. This matters more when you are doing precision work. For rough drilling it makes little difference. Know what your application requires before spending time on this.
Common Pitfalls When Using This Equipment
People ignore the lubrication points. The 660 series has specific grease zerks and oil ports. Using the wrong lubricant can degrade seals or attract metal chips that cause wear. The manual lists the exact grade of grease and oil to use. Do not guess. I used a multipurpose grease once and it gummed up after a few weeks. Switched to the specified type and the problem disappeared. Another issue is ignoring the belt condition. V-belts stretch over time and lose tension. The manual shows you how to check deflection and adjust the motor mount. Loose belts slip under load and generate heat. This can also affect speed consistency. Tightening or replacing belts according to the manual keeps performance stable.
When to Replace Parts vs Repair
Sometimes it is cheaper to replace a worn component rather than repair it. The manual includes part numbers and pricing if you call Grizzly. For example, worn quill bushings are not usually machinable. You buy a replacement kit. Trying to refurbish them yourself costs more in time and tools than the part itself. However, some components are straightforward to rebuild. Gears in the headstock can sometimes be saved if the teeth are not pitted. The manual provides tolerances to check. Measure before deciding to replace anything.
Electrical Troubleshooting
If your machine will not start, check the power supply first. Use a multimeter to verify voltage at the receptacle. Then inspect the overload reset button on the motor. This trips occasionally if the machine is overloaded or the voltage is low. Resetting it is covered in the manual. For more complex issues like intermittent operation, the wiring diagram in the manual helps you trace the circuit. Check the reverse switch contacts and the speed selector switches. These can wear out or collect metal dust. Cleaning them with electrical contact cleaner often resolves the problem. The manual does not always cover this explicitly, but the schematic makes it manageable if you follow the lines carefully.
Safety Considerations
Always disconnect power before working on the machine. The manual includes safety warnings, but they are easy to skip. I have seen people forget to unplug the unit and start adjusting the chuck. That is dangerous. Lockout/tagout procedures apply here just like anywhere else. Also, be aware of sharp edges inside the machine. Metal chips and burrs can cause cuts. Wear gloves when handling internal components. The manual assumes you will take basic precautions, so do not skip them. The 660 Grizzly Service Manual is a practical document that saves you from trial and error. Keep it accessible, reference it when problems arise, and follow the specifications exactly. Your machine will last longer and perform better as a result.
