The cracking fiberglass is a problem that could (and will) cause the mechanism to bind... whether it's causing your problem is the question. It caused mine. It'll only get worse over time. In the past I have cut an irregular-shaped panel (plate) from stiff aircraft sheet aluminum to fit down into the recessed area that the mechanism attaches to, with holes for several of the reguator attachment points. The intent is to spread the torque load across the plate by tying all three of the center mechanism mounts together solidly, along with a couple of more mounting bolts further away from those three for leverage, rather than having the torque work on the fiberglass in one small area. I used aircraft aluminum because I didn't have a good method of cutting steel smoothly to an irregular shape. I used a jigsaw, ruining several blades in making the aluminum plate. I also seem to remember that the attachment bracket for the door arm rest presented some sort of problem in fashioning the plate, though I don't recall how I solved it. Perfect a thin cardboard pattern first before cutting metal; it would be best if you could find an Avanti with a pristine panel to measure/mark hole positions so you get them positioned exactly in relation to each other. If they aren't, you may just perpetuate the binding condition when you install the plate. I roughed the joining surfaces and bonded the plate to the fiberglass on the passenger-compartment side of the door, clamping it tightly until dry, then used slightly-longer mounting bolts to re-attach the mechanism. Not an easy repair by any means, but it did the trick for me. And, of course, adjusting the guides to get minimal slop without binding would also help. I'm not sure what you mean by the regulator guides (its been a long time since I've had them apart) but if you are referring to the plastic wheels, I think you may be able to purchase new ones (try Nostalgic or SASCO) ... you might as well replace them and lube the tracks with white lithium grease while you have it all apart. As for the slack up & down, I don't think it's an issue as long as the window can travel to it's topmost position. I also seem to remember that there are stops (inside the door on an "elbow" attached near the access opening, and near the upper door sill at the rear of the window) to prevent the window from moving beyond the up and down limits. Hopefully you have an Avanti shop manual to refer to. --------- That is a common weak point on the inside of the door panel as the torque of the motor does cause quite a bit of stress on that inside pivot point, and the opposing force gets worse once the fibreglass cracks as the regulator arms now have to fight a lateral push perpendicular to the vertical movement they are supposed to make in raising and lowering the window. It is hard on all the components when this happens; the motor, the mounting point on the door, and the regulator itself. Of course without the feel one would get as raising the window manually with a crank, the only way to tell is for the draw on the motor, and the motor itself is mistakenly listed as the culprit. It is best to operate it with the door panel removed and while raising the window, check and see of the inside fibreglass panel bulges outward. If it does, which it must be doing in your case with the crack in the fibreglass, a repair with a plywood reinforcement and grafts of fibreglass matting will be neccessary to do a proper job. A regular greasing of the regualtor, pivot sliders with Lubriplate will decrease the chances of the fibreglass splitting by the pivot point on the door. Stude newsgroup December 2001. --------------- The shop manual doesn't show as much as the parts book, and doesn't cover power windows, so you're not missing much there. I can't recall how the spring is positioned, you'll have to use common sense to position the spring so it helps, not hinders, the window when it's going up. The adjustments of the window channels also are important, so be sure the window is guided correctly, but still slides up and down easily (by lifting/lowering the window by hand before you connect the regulator arm pins into the nylon bushings in the window's bottom lift channel). And use some lubriplate or white lithium or other suitable lubricant in that lift channel. Also, look for cracked fiberglass in areas where the window mechanism is attached (around the bracket for the arm rests), because this damage weakens the door panel to where things aren't properly aligned and thus the window binds more when operated. If the damage is there it needs to be repaired. It will be obvious if the window is operated with the door upholstery panel removed, and can be seen even with the panel installed because the arm rest will move in and out markedly when the window is operated.