I've always thought the ramp/patio door on my Vengeance 25V was a little on the heavy side. Well, actually a lot on the heavy side. Got to looking at the "helper" springs to see if I could put larger ones in...you can't. But, I counted only four springs and it appeared there was plenty of room to add a fifth spring on the far left side. I don't know if FR forgot to put the spring in or if there are only supposed to be four (other Vengeance owners chime in here and tell me how many there are).
I called Lippert (actually got good response) and they advised the springs were the same on all the patio doors. The rep I talked to said he didn't know how many were supposed to be there but I could order one and if it didn't work I could return it ($21). Got the spring delivered in three days. Big job to install...took less than ten minutes. Door is still not exactly a lightweight but is definitely much easier to lower and raise.
One thing I noticed which impressed me. All of the nuts were secured with blue LocTight. Surprised they would do that since it's definitely more labor intensive than just clamping the bolts down with an air wrench. The nuts/bolts tighten down on the aluminum frame and using the LocTight keeps them from having to be so tight they could bend the aluminum.