Reply from Thule
I heard back from Thule. They agreed that their tech department had given the 40lb figure and offered to resolve the problem by shipping me new lifting assemblies with struts.
Kerry
Hullavator gas spring repair
I purchased a used Hullavator for which the pressure of the gas springs were gone. I replaced the cheap springs with gas springs purchased from a supplier in British Columbia by the name of “Gemini” gas springs. The important criteria were a minimum extended length of at least 22" and compressed length of less than 14" in order to allow the assembly to lock in the extended down position. The force I asked for was about 50# and I received units with a rating of 51# an extended length of 22.5" and compressed length of about 11". This easily lifts my 40lb kayaks with little effort from me while not 'taking’off when released back with no load. To get around the Thule “hollow rivet” design,I drilled them out and later replaced them with chromium bolts (Home Depot), the inner short one cut off and drilled to accept a self tapping metal screw, and the head ground down thinly for later clearance. The longer bolt is not a problem and can be used as is. The bolt diameters are 5/16". To pull the gas spring into position, clamp the arm assembly to a worktable, make a 3" long pulling strip out of thin metal with a 3/8" center hole and small end holes to accept coat hanger or similar wire, bent into a “u” shape. Insert the longer bolt into place. Pull the gas spring back using a racheting strap (I use them to hold the kayaks in place… available at Walmart) until it will line up with the assembly holes and eyelet of the gas spring. Put in the modified shorter 5/16 bolt to hold the gas spring, screw in the sellf tapping metal screw, and grind down as necessary for clearance, and you are done!
Hullavator gas spring replacement.
– Last Updated: Jul-30-16 11:10 AM EST –
I can confirm that both ends of the gas springs in my Thule Hullavators (purchased 2008) are threaded and easily unscrew without the need to disassemble the Hullavator or drill out any rivets.
Be very careful as the spring is under tension which is maximal when the spring is at its shortest length.
The threaded ends of the gas spring are 8mm diameter and accept a 8Mx1.25 nut.
The maximum extension of the spring is 22 1/2" and the minimum is 14".
Using a bathroom scale and a gas spring that was still working and that had been removed I measured the force required to begin compression: 120 lbs.