The Stovebolt Site Forums The Shop Area Paint and Body Shop Installing chrome lock strip in rear window rubber

Even people who have done this for a living...or people who have simply done this intermittently for decades as a hobby know installing the chrome-look lock strip in the rear window rubber isn't fun.

What you'll learn pretty quickly is that the lock strip installing tool you generally get (and even a good professional tool will have the same problems) will ruin the appearance irreversibly. But using a different method, a lot of patience, as much strength as you can muster (in your hands) and careful thought you can install these strips and make them look just as good as any pro installer anywhere.

First get familiar with the design of your weatherstrip rubber (first image below). There's naturally a smaller slot for the pinchweld and a larger slot for the glass. Install this in the cab and let it sit for a day or two. When you install, allow a half inch longer for the corner windows and an inch longer for the center window. Install this so it pushes back on itself. This strip (no matter who made it) will shrink over time and you want the extra to take up that shrinkage. Then install the glass carefully. A popsicle stick and a ball hook tool will help here and if you push/pull gently on the window in/out and up/down, you'll be able to center it and make it get happier with the rubber. You may need an assistant as the glass can fall back into the cab if you push too hard or if it slips out of the rubber slot. Don't use any sealer on these pieces. GM didn't want you to and you don't need it.

The second image below shows the black rubber strip commonly used on this type of strip and the third image shows the chrome-look strip. You'll notice the chrome-look strip does not the ridge at the bottom and if you feel the two side-by-side, you'll see the chrome strip is much less flexible. The absence of this ridge at the bottom and the slicker nature of the chrome-look strip will work to your advantage in installing.

As for the ball end tool, you can buy one or you can make one (as I did). I've made 3 of these and all you need is a bench grinder (or Dremel tool), an old screwdriver and about half an hour of time. You can see the one I made below.

Also, you'll need a screwdriver with a nice straight end. I filed one very straight. You will notice (as you would expect) once you get the strip over the pinchweld and with the window installed, the slot for the lock strip has now become quite a bit thinner (image below). Now on to installing...

Ok, on to installing the lock strip. You can put the seam of the rubber strip pretty much anywhere. On the corner glass, I was taught to put it on the inside (facing the center window). On the center window, I was taught to put it dead center at the bottom.

Start the lock strip at some other point, though. Usually I start the lock strip 180 degrees around the window opening from where the rubber strip seam is. Get some Dawn dish soap. I've also been told Murphy's Oil Soap works well, but I only had Dawn when I did this last week. Rub some on the lock strip (a foot or two) and also on the rubber piece. You won't need too much.

Insert the lock strip into the rubber piece as shown in the first image below. You will basically insert the lip of one side into the top slot of the rubber piece. Insert 4 or 5 inches of the strip at a time. This work will go slowly and you want to be very careful doing it.

Now set your screwdriver on the ledge formed by the lip of the other side of the lock strip and carefully push it upward and into the slot. You can see me doing this in the second image below and you can appreciate why the screwdriver blade end needs to be nice and straight. The popsicle sticks are in the slots to mimic the pinchweld and the glass piece. You'll discover pretty quickly that pushing up on the locking piece pushes up the rubber piece and also that this lock piece makes the pressure on the pinchweld and the glass become very tight...hence the lack of need for sealer. Take your time. Please be careful with the screwdriver as it isn't difficult for it to slide off on you. Occasionally you will need to push against the top of the lock strip with your thumb (or a piece of very smooth wood) to help push it in place and occasionally you may need to run your ball end tool through to help pull the rubber piece up and over the lip of the lock strip. If you make your own ball end tool, please remember to heat the tool with a propane torch before bending it or the metal might break.

You will notice (as you would expect) the straight parts go much better than the curves. At least until you get the hang of this. Have you ever felt like you get good at a task just about the time when you finish? Same thing here. You'll be doing really well at this by the end.

Here are some hints:
On the corners, grip the lock strip and twist it (clockwise or counterclockwise as needed) to make inserting the lip side into the slot of the rubber piece. Hard to put into words, but you'll get the idea when you're working.
Pull the corners of the strip down into the bends to help remove puckers or buckles and pull/push to try to starve the corners for rubber.

I've used this strip made by lots of makers...Steele, Soft Seal, others and I've never seen one which would install neatly without some extra help.

Good luck. If I think of other things, I'll add them

Great explanation Jon.

Thanks Jon!
Your postings are very detailed and thought out...and process intensive.
I am certain to revisit these posts when I am ready to take this on.

You're very welcome. Actually tinnerjohn and I swapped messages about this while the work was ongoing and his input was very helpful also as John has many years of experience at this stuff. I had been hoping for some sort of magic answer...one of those "well if you hold the tool with your left hand and chew gum at the same time" things, but as I feared there were no easy tricks here. As it turned out, the absence of that ridge at the bottom of the strip became my friend in the process. I realize people won't be doing this very often...hopefully, anyway. But hope it helps somebody sometime.