Buck
Club Member
I’ve seen this reported on other forums and finally got around to it myself. I was spurred on by my ride to and from the International with the bike loaded up and the back end feeling decidedly unsettled.
The basis of this is to drain the old oil and replace it with a similar or heavier weight oil depending on preference, my glide is an ‘08 and I understand that at some point Showa changed the internal valving for the air shocks so this procedure may not yield such major improvement on post 2010 bikes.
I removed the shocks and then made up an interference fit so I could attach my Mityvac vacuum pump to the shock which I inverted and then drew the old oil out, an alternative method is to just invert the shock overnight over a suitable container after removing the brass air fitting. The old oil which I suspect is mineral was a lovely dirt brown colour after 50,000 plus miles, I understand it is #5 weight. I got around 12oz out of one shock and 10oz out of the other one.
I then used the Mityvac to put 10oz of Amsoil #10 weight Shock Therapy into each shock and refitted them to the bike.
Previously I was using about 12 pounds of pressure for solo riding and about 16 to 18 when the bike was loaded for camping trips. I initially put in 10 pounds to start with and went on a ride of 294 miles of mixed roads to get them dialled in.
First impressions were that the damping was a night and day improvement but they were far too firm so I reduced first to 8 pounds then to 6 pounds, at 6 pounds it felt great, the best the shocks had ever felt since I have had the bike, I have subsequently reduced the pressure to 4 - 5 pounds which is the sweet spot now solo. The first time I loaded up for a rally after this I used 8 pounds of pressure and even with the bike loaded I was scraping the floorboards in the bends such is the improvement. So well worth a try for people looking for a cost effective improvement.
The basis of this is to drain the old oil and replace it with a similar or heavier weight oil depending on preference, my glide is an ‘08 and I understand that at some point Showa changed the internal valving for the air shocks so this procedure may not yield such major improvement on post 2010 bikes.
I removed the shocks and then made up an interference fit so I could attach my Mityvac vacuum pump to the shock which I inverted and then drew the old oil out, an alternative method is to just invert the shock overnight over a suitable container after removing the brass air fitting. The old oil which I suspect is mineral was a lovely dirt brown colour after 50,000 plus miles, I understand it is #5 weight. I got around 12oz out of one shock and 10oz out of the other one.
I then used the Mityvac to put 10oz of Amsoil #10 weight Shock Therapy into each shock and refitted them to the bike.
Previously I was using about 12 pounds of pressure for solo riding and about 16 to 18 when the bike was loaded for camping trips. I initially put in 10 pounds to start with and went on a ride of 294 miles of mixed roads to get them dialled in.
First impressions were that the damping was a night and day improvement but they were far too firm so I reduced first to 8 pounds then to 6 pounds, at 6 pounds it felt great, the best the shocks had ever felt since I have had the bike, I have subsequently reduced the pressure to 4 - 5 pounds which is the sweet spot now solo. The first time I loaded up for a rally after this I used 8 pounds of pressure and even with the bike loaded I was scraping the floorboards in the bends such is the improvement. So well worth a try for people looking for a cost effective improvement.