Driver's window glass falling off track

[fusion]

I am putting the glass back in my 1976 280z after a restoration.  I have the front and rear windshields installed and now I am starting with the driver's glass.  

I am able to get the glass inside the door and all the guides installed with the wheels in the channels.  The 2 glass door bumpers are also installed.  The glass seems to roll up and down reasonably.  I do not have the window frame installed yet.

Where I am getting hung up is that when I roll the window all the way down so the bottom of the door glass frame touches the rubber bumper at the bottom of the door and then start to roll back up, the rearward roller jumps out of the back of the track that is on the door glass frame. 

 

Window rolled all the way down

 

Starting to roll back up

 

Roller jumped out of track

 

Door glass

 

I have tried adjusting the front glass guide and the rear regulator guide bolts that are on the inner door frame but other than trying to adjust the entire glass rearwards I'm not sure what to do. 

I was thinking that perhaps I need to install the window frame but didn't think that would help with the issue at the bottom of travel. 

Please let me know your comments.

 

Edited September 25 by fusion

[Zed Head]

Something here might help -

 

 

 

[Patcon]

I wouldn't even try to adjust the window tracking without the frame installed

[fusion]

Thanks guys, I'll install the window frame and try again

[dutchzcarguy]

It's a 280z.. not a 280zx! 🤗

[zKars]

You’ve had this glass in the car before the restoration and the window worked correctly then? Or is the car new to you and never used the window before?

Fully agree to put the frame back in as well, since the back of the glass rides in the frame at the rear.

The picture of the glass out of the car showing the two roller tracks tells me this window is from a 240, and I know that using 240 glass in a 280 will cause the “fall off the track” issue. The location and length of the two roller tracks is slightly different between the two. They changed the regulator in the 280 as well to offset it further into the door. 

The way I quickly tell them apart is by looking at the front track. If it is butted up to the frame so that the roller cannot escape out the front, then it’s 240 glass. This appears to be the case, see my red circle.  280 windows allow the roller to enter or leave all four ends of the two tracks. They are also slightly different lengths. 

[fusion]

Wow, zKars, very astute.  You are correct, this window was indeed from another vehicle.  The only reason I didn't want to use the glass that came with the car is because it has more substantial scratches along the bottom of the glass. 

The year of the other vehicle that that the door glass came out of is unknown, I bought a complete door and took the glass out of it.  Upon closer inspection of the door, the inner bracing looks to be different between the donor door and my door: 

Donor:

 

My car: 

You are also correct that the guides are indeed slightly different

 

Donor window rear guide:

 

My car glass rear guide: 

 

Donor front guide: 

 

My car front guide: 

 

Comparison photo, donor on bottom, my car on top 

 

So it looks like I'll need to use the glass that came with my car, or could I just swap to the regulator that came with the donor door?  Not sure what condition it's currently in.  I'm assuming the donor door was off a 240z.

[cgsheen1]

The regulators have a different form factor so the door skin might require modification. Since you have both frames, why not just swap the window glass? Use the good glass in the frame that works with your regulator...

[fusion]

Also a good idea, I have never done that, is it difficult?  Is there a risk of cracking the glass when tightening the new frame?

[dutchzcarguy]

10 hours ago, fusion said:

Is there a risk of cracking the glass when tightening

That's why we have torc wrenches..  😐

Btw, the 5-7 mm difference is not the problem, the place where they are spotwelded is different, look closely to where they are placed and spotwelded.

(Those 5-7mm is just costst and weightsaving from nissan!)

Edited September 29 by dutchzcarguy

[Patcon]

The glass is easily swapped

[Richie G]

If your only problem with the original glass was scratches you should try this first:

 

I had awful roller scratches all the way up and down the window and used that amazon product and it came out like new glass.  Pictures don't do it justice.