I was working on my wifes 1998 formula 500DLX over the weekend and it seemed like the back did not have the springs on it. When it is sitting on the ground the rear sags down about 6 inches, you can pick it up but it falls back down. Everything looks like it is hooked up the right way. When you put the sled up on rollers if you put it in the middle of the track the rear sits up where it should. Do the rear springs need to be replaced? Thanks for any input.