my2kTA

iTrader: (7)

Last week I replaced the window motor in my brother's 2001 trans am since I replaced both of mine 2 weeks before. When rolling the window down and then back up, the window itself appears to be shifting. The front side appears to be lowering faster than the rear. This is further confirmed because when we roll the window back up it sticks 3/4 of the way because its canted. If we straighten the window or put pressure on it, it will roll up evenly.

Is this something that was caused by the window motor being installed offset or do we have a bad actuator? He cant tell me when the last time his window worked and if this problem was around before then. Looking at the door panel itself, it looks like the actuator has been wearing the rivet holes larger than they should be.

Finding info on replacing the actuator or anyone with the same issue was nearly impossible.

wssix99

iTrader: (5)

Something is broken or off the tracks/rollers. It sounds like you are describing this problem: https://ls1tech.com/forums/general-m...-included.html If the damage is really bad, it can cause the problems you describe.

I'd watch the rivets as you move the glass manually. If they move when the glass moves, then that would indicate its the sole issue. I've also had similar problems with the regulator rollers off the small horizontal track inside the doors. Did you use the shbox method or did you pull the regulator for the motor replacement.

my2kTA

iTrader: (7)

Thanks, that sound very similar but his door panel isnt worn as bad. I am thinking we will try the washer method first since we dont have the ability to cut a metal plate.

I used the shbox method to replace the motor itself. I had done both my driver and passenger two or three weeks before doing his. Didnt have any issues with those.

xenergyx

iTrader: (3)

When you replace the motor DONT USE RIVETS USE BOLTS AND FENDER WASHERS. this will keep the motor from shifting against the fiberglass holes and distribute pressure over a larger area reducing breakage. Ive done both manual to auto conversions on both doors and havent had a problem yet with window shifts.......if you know for a fact its not the window it might be the whole door itself .... extreme hard bumps will jack up panel alignments and the doors arent light at ALL

wssix99

iTrader: (5)

This is not the best advice and can actually lead to more door damage.

Cranking down bolts to the point where they prevent slip and do not bear (in a shearing plane) on the fiberglass could crush the material. Not cranking them down and allowing them to slip will actually cause the hole enlargement problem that we are trying to solve here.

The best advice, if bolts and washers are used, is to epoxy the washers to the door panel and using moderate torque on the bolts, (with Locktite) which will cause the bolts to bear on the washers and transfer the loading to the strong direction of the door panel.

GM's special rivets (steel mandrel coated in an aluminum jacket) deform to the shape of the hole and bear properly on the door skin, but we're damned if we do - damned if we don't with them. Drilling out the old rivets often enlarge the door skin holes (its very hard not to) and the new rivets are expensive/require a special tool set.

I think most would advise to not remove the regulator at all, unless its physically damaged. The shbox method allows for motor changes without removing the regulator, which will preserve the condition of the regulator holes.

my2kTA

iTrader: (7)

I have already replaced the motor, thats how I noticed the holes were stretched for the actuator in the first place. The kit from the parts store does use bolts, star washers, and nuts for the motor mounting.

The question I have now is in regards to the actuator bolts. If I go the route of the fender washers (as I feel my brother is leaning that way), do we epoxy them on both sides of the door or just the outside?

wssix99

iTrader: (5)

If the epoxy holds, I would think one side would be sufficient. You just want metal to take the force of the bolt bearing on it vs. the hole in composite door panel. You would only "need" two sides if the epoxy on one washer wasn't strong enough to hold the forces applied to it.

xenergyx

iTrader: (3)

Guess you missed the part about fender washers even in the quote huh ? GM doesnt have special rivets a rivet is a rivet no matter what its for its meant to go in and never come out. This idea is counter productive to the idea of REPLACING a window motor very well knowing your going to have to replace it again because they go bad and your gonna have to DRILL them out again and again. USE A BOLT WITH A FENDER WASHER( SMALL CENTER HOLE WIDE CICUMFERENCE)with an locking thread nut does the same thing only its meant to be removed wont damage the fiber glass because its DISPLACEING THE CRUSHING FORCE over a larger area. IF YOU USE A RIVET and youll need a 1/4 one which are hard to find youll need a larger rivet gun and when you do this you run the risk of actually deforming the hole the old rivet was in and potentialy crushing and cracking the fiberglass around the hole.....asking me how i know ...go ahead and ask

(BOLT PULLS FROM BOTH SIDES) (RIVET ONLY PULLS FROM ONE)

wssix99

iTrader: (5)

If you can't buy it anywhere else in a small quantity, I'd say its special. But I'm sure you've researched this and can tell us where we can get an identical rivet in a manageable quantity, aside from a GM dealer?


If you seek the counsel of a qualified mechanical engineer on this subject, I am certain you will learn that this is not the case.


... Or you can use the shbox method and NOT drill the regulator rivets to change the motor ever again.


That will definitely happen if someone uses the wrong type of rivet.