HOWTO: Replace/Rebuild 75/76 280Z Window Regulator

[Stephonovich]

Since I got my '75 280Z, the passenger window hasn't worked.  Once it came down, it stayed down.  I figured some part of the regulator was broken, and decided to try to fix it.  I found very few threads discussing it anywhere; the best I found was a service manual at XenonS30.

 

This is also where I discovered that they changed the regulator design in '77, making the pieces way beefier.  Oops.  I ended up just re-greasing mine and putting it back together, worked like a champ.

 

I took what pictures I could; I apologize that everything isn't documented.  As the afternoon drew longer I got tired of taking off gloves to snap a picture.  Side note on that, I strongly recommend you wear Mechanics Gloves during this.  You'll be reaching inside the door a lot, and while the metal is rolled, it'd be quite easy to slice your finger.

 

You will need:

 

Optional: A new regulator set for a '75/'76 280Z.  I imagine the procedure is pretty similar for the 240Z and later years of 280Z (2+2 has more parts involved, sorry guys), so do what you can.

Not optional: Lithium grease - I recommend the white spray variety, but I used high temperature goop because it's what I had.

 

Large Philips head screwdriver

10mm wrench/socket - almost all the bolts are 10mm with an integral Philips head.  Wrenches/sockets have a lot more torque potential than the screwdriver, but use what you want.

 

 

 

Start by removing the door trim.  Mine was held on by three screws; one clearly visible on the upper left of the armrest (I assume there's a cover over it normally), and the other two sunk into the lower part of the armrest.  There are also some plastic snap-in pieces on the perimeter.  My interior is in pretty bad shape overall, so these popped out quite easily for me.  YMMV.  Note that you have to pull off the following two pieces to get the door trim off.

 

 

Clearly aftermarket (previous owner), these just unscrew.  No idea about stock.

 

 

The silver plate that covers the door latch is held on by a single black screw.  OK, pull the trim piece off!

 

 

It should look like this when you pull the trim off.  

 

The two screws/bolts on the far left center hold the front guide channel (called a front sash in the manual) in place.  

The two screws in the middle (yep, there should be four - that's how I found it) hold the crank assembly in place.  

Kind of washed out, but the two nuts in the oval indentation, right side, above the hole - those hold the rear guide channel in place.  It has studs attached to it, which protrude through the door.  

There are two screws/bolts holding the door handle to that metal plate at the bottom.  Remove them, and wiggle the cable off the handle.

The four nuts holding that metal plate in place come off, which allows you to pull the plate out.  You'll need all that room, believe me.

 

You also need to pull the window trim (the metal runner along the top of the door, parallel to the ground) and the door sash (metal trim that the window rolls up into) before you can remove the regulator and glass.  The trim just pops off; the door sash has screws/bolts - two on the leading edge, on the first angle going forward from the flat; three on the trailing edge, where it meets the door jam (one at the bottom, two near the top).  You also need to remove the window crank - mine was already off, as it was broken.  From what I've read, there's a C-clip you have to pull off with needle nose pliers.

 

There's probably a better way to remove the assembly; I unbolted everything (supporting the window) and then pulled it out one by one.  The window comes up through the top with some trouble, and the crank assembly comes up with a lot of trouble.  The manual states it can go through the holes in the door, but I wasn't able to do that.  Pull everything out however you can.

 

 

These two demonstrate the year differences.  The newer looking stuff is froma  '77.  Not only is it beefier, the arrangement of the spring and gear is different.

 

And, this is where the pictures stop.  Not much to it after this.  If you have a new set, make sure the guides are well greased.  If you're re-using your set, as I did, clean everything off well, and re-grease.  I used PB Blaster to get the old gunk off everything.  

 

For re-installation, the easiest way I found was to install the front sash first, but only secured with one bolt.  Angle the window towards the front of the car and slide it down, then line up the guide rail on the window with the front sash and partially slide it in.  Use the window crank to raise/lower the regulator until the rollers are near the guide rails on the window.  Use force, coercion, and magic dances to line them up.  It took me about 10 minutes to get all three of them aligned.  Note, you can pop the long gear off the crank if you force it past its normal range of motion.  If you do that, you'll have to pull the regulator out and push the gear against the tension spring to get it to re-engage the crank.  Once they're all in place and tightened, raise and lower the window, making sure all the moving parts are greased as you do so.

 

Replace the door sash.  When you roll the window up, you will probably notice that it's cockeyed in some way.  If it's wrong parallel to the top of the door sash, loosen and adjust the front sash (the long guide near the front of the door).  If it's cockeyed fore or aft, loosen and adjust the guide channel (the small one to the rear of the door) - specifically, if it angles to the rear of the car, move the guide channel up; if it angles to the front of the car, move the guide channel down.

 

Once the window is aligned, replace all trim, and hope you don't have extra or missing bolts.

[Curtball]

Dated post, but very helpful for me. Now I have an idea of what I'm about to dive into

[z240]

Generally good information here. Couple of points to help those with stubborn windows get them back in shape.

 

First, it is not necessary to remove the outer winder frame (sash) to get the glass out or in. With the outer squeeze trim off, the glass easily comes out the outside of the frame. You have to have the front vertical guide track off and the short guide track loose.

 

Second, the cause of many difficult windows to roll up or down is caused by excess friction in two key places. One is in the front guide track where the white nylon bar that is attached to the glass frame runs in. The grease tends to harden in there. That white nylon bar is often cracked or broken. Replace as needed.

 

Second is the other end of the glass where the back of it slides in the felt that is inside the window sash section that is in the back of the door. The felt or u-channel lining (can't think of its official name) can get bunched up. Remove or replace. Some grease in there helps the glass edge to slide as well.

 

Maybe equally third are the tracks where the three wheels on the regulator run, (two on the glass, one on the door). These can be caked with stiff old grease and dirt. Clean and re-grease.

 

Now all this friction makes folks wind that crank really hard, and it gets worse and worse. What results is the arms of the regulator get bent, which really makes the whole thing bind up even more. Remove the regulator, the glass, straighten the reg arms (each of the three metal arms with the wheel at the end are supposed to be dead straight and parallel to each other (except where they cross of course). Make them so if not. Remove all old grease from the guide channels, replace with anti-seize or something thickish that will stay in place.

 

Re-assemble and you're off. Getting the glass back in the trick. Most important thing is you will note that one 240 glass, there is one glass roller channel that has only one end where the roller can go in, that end has to go on first, then do the rear one.

 

Hope this helps. Working in the doors is no fun, but be patient, you'll get it.

Edited November 22, 2015 by z240