I have an early 80's sunline truck camper with the 3 tripods jacks. They all work but one clicks like it's got a gear skipping but still works. The head that needs to be adjusted is just a square head...
Those jacks are almost identical to the Rieco Titan tripod jacks except the Jack head is no longer square . There is standard duty and heavy duty . Heavy duty has has chain on the tripod spreaders . Give them a call , they may have advice/parts for yours . I suspect they are the original manufacturer or bought out the original company . Good luck , let us know h ow it works out .