Replace zipper on back window of Jeep top?

[scott_san_diego]

Last week had a customer drop of his convertable top off of his Jeep.  The frame and top.  The old zipper on the back window isn't working around one of the corners, looked like the teeth getting chewed up.
I was able to get a jeep replacement zipper for the back window.  Had my employee replace the zipper.
Called the customer to let him know the top was done.  He came by and picks it up.
Calls me 3 hours later and says the back window will not zipper shut all the way.  Told him to bring the jeep with the top on it, so I can look at it.
The zipper starts on the left side and zips closed on the right side.  It appears that right side is coming up short and the left top corner of the window itself there is some bunching of the glass.  The glass is not smooth.  It is more wavey.
Any suggestions of what the problem might be and how to fix it would be greatly appreciated.

Thanks Scott

[mike802]

Sounds like the top may have shrunk, even though tho owner is able to install it, the leverage is just not there for zipping.  Sounds like it may be time for a new top.

[scott_san_diego]

The rest of the top and side windows are in good condition and fit properly.  Just the right side botom where the zipper is to end is coming up about 2" short and the window looks to be a little twisted.  Like I said before the upper left corner looks to be a bit wavey and not spread out. 
Guess I will try to undo the zipper on the window and try not to pulll the zipper  or put to much tension on it while sewing.

[JuneC]

The zip needs to be really stretched on the outside of the curves and bunched/folded/pleated on the inside of the curves.  That's why when we sew smileys in marine canvas we always sew on the zip complete before we cut the material - it's nearly impossible to get everything lined up if you're sewing each half independently.  I did a Jeep rear window zip replacement once and I'll never do one again. 

My advice would be to remove the one zip half that creating the biggest problem, zip it up, lay it on the other fabric where it will be re-sewn, and mark every 4 to 6 inches along the straight edges and every inch on the curves to be sure you get both halves where they should be.

June

[Mike8560]

I agree with June it's got to be missalinged  mark were you want the zipper to be sewn. What I think June meant was to pick the stitches out of say the widow side of the zipper leaving the other side sewnthenwith the window in the proper position make reference marks o. The ziper and window and sew it so they line up

[mike802]

I used to get a lot of jeep zipper repair work and it was always a PITA.  The last time a woman came into my shop and asked how much it would be to repair the same zipper you are fighting with, I had just bought a new top for my Wrangler from Summit Racing.  I told her it would cost at least half what a new one would and she would still have an old top, she decided to just replace the top.  Mike and June certainly have more canvas experiences than I do, could probably do it faster to, so I would not second guess their judgment.  I stay away from that kind of work today because I am just to busy with furniture. It gets my sewing table and machine filthy, not the type of environment you want fine silks, or light colored cottons around.  :D

[scott_san_diego]

Thank you all for your responses.
This morning my customer dropped off his jeep.  We found my employee did not make the zipper that attaches to the window long enough.  We took the window zipper off, and found another half of zipper that would work.  We zipped that onto the zipper half that was attached to the top.  Marked where it ended.  Found the center of the window and the center of the zipper half.   Started sewing about half way up the window on each side. Matched the zipper center to the window center, sewed about 15" on each side.  Then we had to gather the extra zipper around each of the corners.   Put it back on and it worked out.  Customer was happy.  I had a very expensive learning experience for the day.  Never do one again.
Never had a chance to come back to the board during the day to see everyones responses.
Thanks again.  Scott