Steps To Replace Elevation Threaded Rod (CB)
Service Procedure SP-CB-190703-02
Tools & Supplies Required for This Procedure:
- 17mm combination wrench
- 15mm combination wrench
- 2.5mm Allen wrench
- Small tray or bag to hold loose small parts
- Small block of wood, approximately 1” x ¾” x 3 ¾”
- Vise-grip pliers
- Soft towel
- Snap-ring pliers with bent tips
- Good quality bearing grease
Parts required for this procedure:
- 1 ea Elevation Threaded Rod, P/N CB104 115
- 1 ea 14mm External Retaining Ring, P/N CB104 286
- 2 ea Ball Bearing Assembly, P/N CB104 116 *
- 1 ea M10 x 20 x 1.5 flat washer, P/N CB104 118*
- M10 x 1.25 Nylon locknut, P/N CB104 119
(*some of these parts can be re-used from the parts removed from the saw)
- Carefully read instructions all the way through before starting
- Before disassembly, remove all sawdust from inside of cabinet.
- Remove the four bolts holding down the table top with a 17mm wrench.
- Loosen one of the table alignment set screws with a 5mm Allen wrench. Mark this corner of the table so you’ll remember which one later.
- Remove the table top.
- Turn the gears to expose the set screws in the existing miter gears – loosen these with a 2.5mm Allen key. Using a 17mm wrench, loosen the nylon locknut on the end of the vertical elevation shaft, to permit its easy removal in a later step.
- Raise the elevation assembly all the way up, which will leave a gap to fit the small block.
- Fit the block into the gap behind the threaded rod so that the elevation assembly can be supported while the threaded rod is removed and reinstalled.
- Lower the elevation assembly onto the block.
- Pull outward on the elevation handwheel to partially remove the horizontal elevation shaft, taking care to catch the miter gear, key, thrust washer and wave washer as they slide off the retracting shaft. (The proper order when replacing the washers is wave washer>>thrust washer>>miter gear with key pre-inserted.)
- Remove the nylon locknut, and pull down on the vertical miter gear and key to remove them from the shaft.
- Wrap a soft towel around the top of the elevation threaded rod and grip it gently with a pair of vice grips. Back out the rod being careful to catch the bearing assembly that will fall out of the bottom of the rod assembly. Note that the Acme threads are left-handed.
There are two sets of bearings: one that sits in the top of the lower casting and one that is inserted from underneath, which will fall down along with the miter gear as the rod is extracted. Each assembly consists of upper and lower bearing races and a ring of caged ball bearings which is sandwiched between them.
Note: At some point, the snap ring that is in the groove just below the bottom of the Acme threads will come into contact with the bottom of the threaded casting. If the tabs are accessible with the snap ring pliers, use the pliers to remove the snap ring. If not, continue backing the threaded rod out – the snap ring will either break off or be forced out of the grove and become removable. If this method is used, make sure the threads in the casting are clear of any bits of broken snap ring.
- Continue to back the rod out until it is completely free of the trunnion assembly. Retrieve the upper bearing assembly for inspection, cleaning, and possible replacement, leaving the upper portion of the lower casting clear and ready to accept new parts.
- If the bearings are in good condition, they can be cleaned and reused. Lubricate the bearing set with bearing grease before installation.
- Install the bearing set in the upper part of the bottom casting. Due to space limitations, you may need to do this one part at a time. Insure that the curved part of the bearing races is toward the bearings, and the flat part faces outward.
- Ensure that the replacement threaded rod is clean and that the first 1” of threads are well lubricated with a good quality bearing grease. Pre-lubricate the threads in the trunnion assembly with the same bearing grease. This will ease assembly and save having to lubricate them later after the threaded rod is installed.
- Run the rod in until the snap ring groove is just visible (yellow arrow).
- Using the snap ring pliers, carefully spread the new external retaining ring and place it partway up the shaft end of the threaded rod.
- Using the 15mm combination wrench as a fixed leverage point around the shaft just below the partially installed snap ring, continue to run the rod inward so that the snap ring is pushed up until it snaps into its groove.
- Run the shaft the rest of the way in, passing through the upper bearing set and out the bottom casting. Lubricate the shaft as you thread it into the casting. Note: if there is a slight misalignment getting the shaft through the first bearing race, it sometimes helps to slide the race onto the shaft ahead of time.
- As enough shaft becomes available, install the lower bearing set and the vertical miter gear. Note: it’s usually easiest to slide the gear on, then turn it until the keyways on the gear and shaft line up, then insert the shaft key. At this point, install the washer and nylon lock nut – don’t tighten the nut all the way just yet.
- At this point you can reinstall the horizontal shaft. Slide the shaft into the bore in the front trunnion; as the end begins to protrude from the hole on the other side, fit the wave washer, thrust washer, and new miter gear on the shaft. Continue inserting the horizontal shaft until the gear is well seated on the shaft, and meshing well with the miter gear on the vertical shaft.
- Tighten the set screws on the miter gears, and adjust the nylon stop nut on the vertical shaft for smoothest operation of the elevation assembly. You want it snug, but not tight enough to bind the bearings. Raise the elevation assembly to the very top and remove the small support block, or you may find yourself wondering why the saw won’t lower again. Test the elevation assembly through its entire range of travel to be sure everything is operating smoothly.
- Replace the table top and check the alignment using the procedure starting on p.46 in the SawStop Owners Manual. If you take advantage of your set screw settings from step 4, you can usually avoid having to make any significant adjustments. Simply pivot the table up against the set screw you didn’t loosen in step 4, and then re-tighten the loose set screw, and you should be very close to where you started.
Contact the SawStop Customer Support Center with any questions or suggestions:
Call: (503) 582-9934
Email: [email protected]