Add A Zerk Fitting To Your Swing Arm Shaft
Thanks to Rudi Keifer (Roc Doc)
with additional tips & pics from David Parsons “Sarge” VROC 16025
Objective: Prevent having to go through the Swing Arm removal and lubrication process every 7500 miles by simply installing a grease fitting.
The fitting was installed by drilling a hole through the thick frame cross-member behind the engine, going in from the rear where the wheel normally is. I first removed the spacer that lives inside the bearing cavity, between the two bearings. I left the bearings in place since it
requires a special tool to pull them out. Did cover them with rags though so I wouldn't get metal shavings on them.
After pre-drilling I tapped a 1/4"-28 thread into the hole, and inserted a 45 degree angled grease fitting from ACE Hardware ($1.20). Then I had the brilliant idea to clean out the cavity with carb spray cleaner before re-greasing. Nothing wrong with that, except I had just repainted the black frame parts where the road mung had chipped off the paint. The carb cleaner cleaned all the crud out of the bearing cavity, and also did a good job removing all my fresh paint again on the outside. Duuh. I blew out all remaining spray cleaner with compressed air, dried everything well, then gave the bearings a light greasing with high quality grease.
Once you got the center spacer out you might have wondered to yourself....self, how is the grease actually going to reach the bearings? Here's the trick. You cut some grooves in the spacer as shown in the photo from Old Sarge (left). The specs are: A ˝-inch band around the middle of the spacer 1/32-inch deep. Two slots, 180-degrees from each other, end-to-end, 1/32-inch deep. The combination of grooves allow grease to move through the zerk fitting then 'around' the spacer until it finds the horizontal slot. It'll flow along the horizontal slot then down between the center and outer spacers and into the bearings. Cost of having a machine shop do this work for you should be around $35. Some shops have a minimum charge so be sure and get up front pricing so there are no surprises.
An option is to drill a hole in the center of the spacer along with making the grooves around the outside (you don't know if the hole will stay lined up with your zerk fitting) so the grease can flow around the spacer until it finds the hole then down and into the cavity with the swing arm bolt and bearings as shown here Feels like you're falling down the proverbial rabbit hole eh? That's a shot of the needle bearings (outer edge) and the bolt shaft. Note the hole about the 8:30 position for grease entry.
Put your bike back together and go ride!