Saturday my dealer replaced a leaking shock for me and Sunday I drained the stock fluid out of the shocks and replaced it with 10W shock fluid. I didn't have the opportunity to ride the bike until today. My butt and back say that the shocks are much better damped now than they were from the factory. A bit firmer on small bumps but the bigger stuff doesn't launch me off the seat any longer. I am running 25 PSI in the shocks but I am going to drop it down to 15PSI before my ride home and see how that is as I don't thing I'm getting enough loaded sag. I had my 245# self, my road tools in the saddlebags and a case of bottled water in the trunk.

 

Best "under $10" improvement I have done.

 

This is one thing I have never done, Can you change the oil with the shocks installed?

 

How do you even do it?

 

In theory perhaps but it's easier if they are off the bike. You would have to use a vacuum pump with a small tube to remove the oil from the shocks.

 

Here is an old post from when I did it a couple years ago.

https://www.hdforums.com/forum/touri...il-change.html

 

I removed the shocks one at a time (leaving the other shock on so that I didn't have to support the rear wheel).

I removed the air line fitting from the shock using an 11mm socket.

I held the shock upside down over a 5 gallon bucket and used a blowgun with a rubber tip to pressurise the shock body. I had the compressor off and drained the air tank down to 40 PSI so that I wouldn't blow out the seal on the shock. When you remove the air gun from the shock the oil gushes out. I did this about 6 times to be sure I got it all. It will spray a bit of oil around so keep that in mind. If you keep the shock end below the lip of the bucket it helps keep the spray contained. I probably should have only used 5-10 PSI air pressure, it would have been enough to push the oil out without so much spray.

I hung the shock right side up in the bucket using a steel rod through the top eye of the shock. I measured out 12 ounces of shock fluid in a beaker. Using a 150ml syringe ( ) with a piece of tubing on the end to make a seal I drew about 1/2 a syringe full at a time from the beaker. Push the end of the syringe with the tubing sleeve into the port on the shock to get a good seal. Draw a vacuum on the shock by pulling up the plunger on the syringe (the air in the shock will bubble through the shock oil) and then inject some of the shock oil into the shock. Repeat until the syringe is empty and repeat that until the beaker is empty. I filled and emptied the syringe 4 or 5 times per shock.

Put some teflon tape on the air fitting threads and reinstall fitting in shock.

Install shock to bike.

It took less than an hour start to finish to complete both shocks.