So, as some of you recall, I have a SB9A that I picked up early last spring. We're slowly becoming acquainted & during that time I've identified a few things that wanted repair/upgrades. This particular journey was all about the drive system. There were 4 broken teeth on the tri-cone pulley, my "B" belt drive sucked & while I had the spindle apart I thought I'd replace the thrust washer w/ a Timken needle bearing setup.
I only have a single photo of the end product enclosed, it was pretty much a straightforward task. I accessed 2 videos online, one to disassemble the spindle & another to disassemble/reassemble the back gear ass'y.
1) I bought a new used tri-cone pulley from 140mower, all 38 back gear teeth intact. Thx, Don! I disassembled the spindle ass'y using 1/2" all-thread, heavy fender washers and a large socket per a video I found online. It was a simple issue & everything came apart easily. I also needed to remove the back gear ass'y for the belt replacement;
2) My "B" belt drive would, when under load, slip off the pulleys. I never liked the functionality nor the look of it & thought the countershaft hung out the back way too far (offending my tender sensibilities), and when I went looking for a serpentine belt I sized one around 8" shorter to pivot the countershaft ass'y closer to the lathe. This part proved to be the most time consuming portion of the exercise, as driving the countershaft out of the tri-cone pulley was a bit of a bear;
3) In order to accommodate my new, shorter belt, I needed to modify the turnbuckle system. Rather than struggle w/ cutting new LH threads in a shortened existing turnbuckle, I hit PA & found one that suited my purposes. The only issue was that I had to drill the ends out to 3/8" from the 5/16" it came with. The stock pin holes were offset, rather than centred, so I elongated them w/ a round file closer to centre before drilling them to size;
4) As noted, I eliminated the thrust washer & installed a Timken bearing & two washers. There was more than enough thread on the spindle shaft to accommodate the additional thickness.
Job took me about 2.5 hours from start to finish, bit of cleaning here & there, had the vids cued up for reference. The only thing the vids didn't address was the oilers for the spindle shaft. The oiler wicks get pushed up against the spindle shaft by the springs underneath them. When you remove the shaft, they pop up. Upon reassembly, the wicks needs to get pushed below the surface of the shaft so they don't get torn off when inserting the spindle shaft.
To the lower right of the shiny new thrust bearing ass'y you can see the LH spindle oiler. Just above it is a small hole drilled in the casting. There's one on the RH side, too. Prior to re-installing the spindle shaft, you need to insert about a 4" length of wire while holding the wick down with your other hand. The wire will now hold the wick down while you install the spindle ass'y. You need a fairly stiff piece of wire to hold the wick down. And, don't forget to remove the wire when everything is battened down. Make sure everything has a coat of oil, assemble, tighten, adjust, fill oilers, spin by hand, spin under power, et voila!
I've made some chips since reassembly, LH bearing remained cool, RH bearing was slightly warm. I'm good w/ that.
The only issue is I need to adjust the tension of the back gear ass'y. When I engage it & apply power, it immediately kicks out. I'll have to pull out my South Bend lathe manual & read up.
You may also note my shiny new Bison 5" 3 jaw chuck and my new to me AXA QCTP system.
I only have a single photo of the end product enclosed, it was pretty much a straightforward task. I accessed 2 videos online, one to disassemble the spindle & another to disassemble/reassemble the back gear ass'y.
1) I bought a new used tri-cone pulley from 140mower, all 38 back gear teeth intact. Thx, Don! I disassembled the spindle ass'y using 1/2" all-thread, heavy fender washers and a large socket per a video I found online. It was a simple issue & everything came apart easily. I also needed to remove the back gear ass'y for the belt replacement;
2) My "B" belt drive would, when under load, slip off the pulleys. I never liked the functionality nor the look of it & thought the countershaft hung out the back way too far (offending my tender sensibilities), and when I went looking for a serpentine belt I sized one around 8" shorter to pivot the countershaft ass'y closer to the lathe. This part proved to be the most time consuming portion of the exercise, as driving the countershaft out of the tri-cone pulley was a bit of a bear;
3) In order to accommodate my new, shorter belt, I needed to modify the turnbuckle system. Rather than struggle w/ cutting new LH threads in a shortened existing turnbuckle, I hit PA & found one that suited my purposes. The only issue was that I had to drill the ends out to 3/8" from the 5/16" it came with. The stock pin holes were offset, rather than centred, so I elongated them w/ a round file closer to centre before drilling them to size;
4) As noted, I eliminated the thrust washer & installed a Timken bearing & two washers. There was more than enough thread on the spindle shaft to accommodate the additional thickness.
Job took me about 2.5 hours from start to finish, bit of cleaning here & there, had the vids cued up for reference. The only thing the vids didn't address was the oilers for the spindle shaft. The oiler wicks get pushed up against the spindle shaft by the springs underneath them. When you remove the shaft, they pop up. Upon reassembly, the wicks needs to get pushed below the surface of the shaft so they don't get torn off when inserting the spindle shaft.
To the lower right of the shiny new thrust bearing ass'y you can see the LH spindle oiler. Just above it is a small hole drilled in the casting. There's one on the RH side, too. Prior to re-installing the spindle shaft, you need to insert about a 4" length of wire while holding the wick down with your other hand. The wire will now hold the wick down while you install the spindle ass'y. You need a fairly stiff piece of wire to hold the wick down. And, don't forget to remove the wire when everything is battened down. Make sure everything has a coat of oil, assemble, tighten, adjust, fill oilers, spin by hand, spin under power, et voila!
I've made some chips since reassembly, LH bearing remained cool, RH bearing was slightly warm. I'm good w/ that.
The only issue is I need to adjust the tension of the back gear ass'y. When I engage it & apply power, it immediately kicks out. I'll have to pull out my South Bend lathe manual & read up.
You may also note my shiny new Bison 5" 3 jaw chuck and my new to me AXA QCTP system.