Power Window Motor Replacement, Back Seat Door

Near step-by-step instructions and tips
A.     It is difficult to remove the pull strap without breaking the plastic under it unless you can first examine the construction. This is impossible with the strap in place.  The problem is that the lower rim of the trim is too thin to withstand any pressure. This statement is for the rear attachment.  The front attachment point comprises a wider rim and is more robust.

1. I used a plastic crowfoot trim tool to compress the lower tabs. I did not compress them enough and upon lifting I broke the trim because I did not clear it.  Next time I’ll use a metal scraper blade and press harder.  The upper rim is more robust and should not break even if you bear hard against it.
   
2. Other trim pieces are marked ABS. I’ll use an ABS compatible cement to repair the broken piece.  If possible I’ll post how I did the repair.
   

B.     My window was stuck closed.  I was still able to jockey the panel loose.  The rear edge came loose first. (In retrospect, since the windows do not lower fully the position may be irrelevant)
C.     Once the panel was off I switched the key to on and rapped the motor with a small hammer while pressing the window button.  When the motor started running this verified than the motor was the problem. I could proceed with confidence.
D.     I taped the window in the position of open 3” or so to access the regulator parts. (On reassembly I used an inflatable wedge and recommend your acquiring one)
E.      With a Sharpie, circle the bolts on the inner door skin holding the lower roller track marking the bolt positions.  The position of this guide is a window adjustment. Since we are not replacing the regulator the original position should be used, but you need to mark it to do so.
F.      In the upper roller track we did not have oval guides but rollers. Unlike others I did not pry them loose. It is easier to drill out the 1/8” rivets at each end of the upper roller guide and remove as a unit.

1.  I re-positioned the window to do this.
   
2.  Later the window dropped but it hits the bumpers and this is not a problem. (In other situations the window can fall into the door).  Repeating, I would use an inflatable wedge the next time and avoid this.
   
3.  If I were replacing the rollers it seems easier to remove and do all on the workbench
   
4.  The rivets will be replaced with #10 by ½ bolts and nuts.
   

G.     Last the ¼” rivets holding the motor to the inner door are drilled out.

1.  Cut and grind off any excess rivet mandrel.  I used a Dremel and cut-off wheel
   
2.  Dimple the center of the mandrel with a sharp center punch
   
3.  Further dimple the center of the mandrel with a sharp 1/16” drill.  It is important to drill the exact center of the rivet when finishing with your larger drill.  Starting with a small drill helps to accomplish this.
   
4.  Switch to a 5/16 drill and drill out the rivets.  Any time you are drilling out aluminum rivets use high speed and light pressure. The sharper your drill the less pressure because you do not want the drill to bite and spin the rivets.
   

H.     The GM service manual states in plain language that the motor and regulator are replaced as a unit.  The motor was not intended to be replaced. There is no access to punch out and replace the center motor-to-regulator rivet and this is probably the reason it was considered non-replaceable. What I call the “center rivet” is the one furthest from the motor.
I.       Delco, Dorman and others sell replacement motors; no one sells regulators so now it is apparently considered a serviceable item, but the non-accessible rivet has to be drilled out.  Here’s how I replaced the “non-replaceable” motor after removing the assembly from the door.
J.       The motor itself was easy to find even in my small town probably because it has multiple applications.  It comes with three adapter pigtails.  Find the right one and connect it to your vehicle’s harness to verify you’re ready to do the physical install.
K.      We need to drill an access hole in the regulator arm to reach the center rivet. Connect the motor to the car and run it until the pivot arm points directly away from the motor. In other words the pivot arm is aligned with the pinion gear and the spring center.

1.  You then will have some meat to drill into
   
2.  You will drill through both the pivot arm and the sector gear beneath.  You will drill through teeth on the sector but they are vestigial teeth from the manufacturing process.
   
3.  Use a drill press if available for repeatability.
   
4.  Drill a pilot hole through the dimple side of the rivet all the way through the rivet and out through the sector gear and pivot arm. Use an 11/64 drill
   
5.  Turn the assembly over and drill back through the opposite direction with a ½ inch drill. Go slowly.  Once you’re through the sector gear STOP. You will have started to dimple the rivet head by now.  That’s okay but do not drill into the regulator frame.
   

L.      WARNING Use clamps and a bolt through the sector to control snap back of the clockspring. Follow instructions elsewhere for details
M.    Drill and drive out the rivets in the normal fashion. Note, the expansion end of the rivets on my vehicle would not pass through. I had to cut off one end of each rivet with a cutoff wheel
N.      Dorman motors come with bolts to replace the rivets. Attach the new motor to the regulator
O.     Grease the slides with bearing grease.
P.      Secure the window in the near closed position.  This time instead of tape I used an air wedge catalog number 56899 at Harbor Freight
Q.     Connect power and insert regulator into the door
R.     Attach the lower track loosely
S.      Connect the battery and run the window regulator down until the upper track can be aligned with the attachment holes on the lower window frame
T.      Insert #10 x ½ bolts from the rear, install nuts with Loctite blue. You may not like this method, preferring to pry the ball-and-socket joints apart with a slot-tip screwdriver then pressing back together.  The bolts require small hands, nimble fingers and patience as only a wrench will fit on the rear side. The reason I prefer the bolts is they are simple and predictable though requiring patience versus a quick possible knuckle buster. If I had an end-tip Pop riveter I would try using rivets.
U.     Apply Loctite and install two of the regulator mounting screws (where rivets were drilled out previously).  Jockey the window and/or window switch as necessary to get two diagonal holes to align.
V.     Once two screws are loosely installed, apply Loctite to the other two screws and install.
W.    Use a stubby or right-angle screwdriver to hold the screws inside the door and tighten the nuts. An electric impact driver is helpful. You may need to move the window to access the top screw.