Dan, is it this one? http://www.ebay.com/itm/Monkey-Grip-...-/230535671106 I've bought them at auto parts stores for around $2, and have used them as 'grease towers' on Tamiya semi trucks, (along with a 3/8" chrome spring cap to cover the end). The 4mm flanged nut that holds the wheel onto the axle fits right inside, like it was made to. I never thought of using them for VVSS bogies, but that's a great idea - I'll bet they bind a lot less on the springs than the Tamiya Sherman spring tubes do.