Ever since my original tailgate motor went out in my 72 Vista back in November of last year, I've had nothing but problems with my tailgate. First, I determined that it was, in fact, the motor that had gone bad, so I got a Cardone window motor that was exactly the same as the old one except for the mounting posts were too long. I cut them down a bit so that they were the same length from the casing as the old one. At first, the window worked just fine. Until one day, the screws that held the little gear that works the regulator to the gear that is worked by the worm in the motor sheared their heads. This was remedied by new machine screws, and again, for a few weeks the window worked fine. Until one day, the regulator roller on the driver's side wore out. I SEEM to have fixed that permanently, though. But low and behold, once again, the machine screws in the gear mechanism sheared their heads! So this time, I went with something stronger than stainless steel and went to Fastenal and got Zinc machine screws. That worked fine until I decided to just rebuild the window tracks with new felt and all that. Everything went fine and I put everything back together after I rebuilt the tracks and I worked the window up and down; up and down to make sure it would last another 43 years when all of a sudden, the gear sheared the machine screw heads AGAIN! So I replaced them. Again. Has anyone else experience this much headache over their tailgate? Am I doing something wrong? Also, sometimes when I bolt the motor onto the regulator bracket, the teeth for the gear don't connect fully with the regulator teeth and when I work the motor, it doesn't move and I can hear the teeth rubbing together; missing. This is remedied by nudging the motor as close to the regulator as I possibly can and torquing the mounting bolts pretty tight. I have the fisher body manual for this car, but can't really find anything on the particulars of this motor; nor have I been able to really find anything on net. AS of yesterday, I have brand new zinc screws in the gear assembly, greased to hell and back, of course, the motor nudged tightly against the regulator and mount and torqued rather tightly and the motor works fine. But to be honest, I expect something to go wrong in a month or so. Any insight into the particulars of tailgate windows will be greatly appreciated. Thanks, Buz
Your problem is using screws. Remember when you drilled out the rivets to remove it? That's what is required to reinstall it, regardless of what they include in the aftermarket rebuilt box. They are large steel rivets and require a large rivet gun to set them. My rivet gun has handles almost 3 feet long. After a couple of unpaid comebacks for your problem, I went out and bought the rivet gun and a supply of rivets. I recently ran out of them and went to my local body shop and he sold me a few.
Screws regarding the gear assembly? No, I never drilled out any rivets. Unless the previous owner already made similar repairs. When it first initially happened back in November, I had the car for 3 years and NEVER had this happen before. Then, in November, when the motor initially went out, I simply replaced the gear assembly into the new motor. And THEN, the screws gave out. I know it was screws because I found the screw heads inside the tailgate when they first initially sheared off. That, and... the little studs that hold them in place. I have attached some pictures as a reference...
Or were you talking about possibly the motor itself being riveted to the regulator? That definitely wasn't either. It was bolted. And again... for 3 years I never had any sort of problem with the tailgate until one day, it just wouldn't come down.
Yup, I was talking about the motor itself. Most screws are made from 12L14, which is leaded steel, because it cuts easily but it very weak. You need to find some hardened screws.
No rivets for the 72 Vista Cruiser tailgate regulator or motor. Everything was bolted - 7/16 head, 1/4-20 thread w/SEMS washers.
It appears someone repaired that motor gear. Replaced dozens (maybe hundreds) of that style GM window motor over the years, never saw any with screws holding the gear together like that. The gear probably failed, with the two gear sections separating. Not a bad fix, except the screw alloy doesn't handle the torque generated by the motor. A new gear would probably correct the issue.
I had a '70 squire that had a bunch of problems with the back window one of which was the gear. It was two parts and looked like when the window was hitting bottom or top it kinda gave a bit. It finally gave out and the two haves wouldn't engage. I filled it with some industrial epoxy and made it one. I was just careful when it got to the top and bottom not to hold on to the power switch to long. If it's of similar design you could add epoxy to the gear set or another set of machine screws to add strength. Good luck
I wouldn't add too much strength to just the two screws or you may end up cracking that plastic gear instead of the screws.
