Try using TAmiya's Anti wear grease on the suspension arm, rods and all moving parts. This grease, although is a grease, is very thick and causes the speed of the movement to slow as its very sticky
Thus I hope this will act as a form of "damper" I use this grease on my "grease shock" those cheap RC cars where they are not equiped with an oil shock
Hope this helps
Tee S S
www.modelmotobikes.com