I installed a new Robbins top on my M1 (91). The original top lasted 12 years, although for the last two years I resorted to folding the plastic window because the zipper was pretty much shot. Through careful cleaning and the use of Rain-X, the window was actually in reasonable condition. But, the folding was finally causing the plastic to craze, and I saw pinholes on bright days through the vinyl at the creases above the side windows. And, I couldn't simply drop the top at a stoplight since I had to assist the window as it folded. So, I decided it was finally time to install a new top.
The top I chose is a Robbins Sunfast cloth top with a glass window. It does not have a zipper. I guess the trauma of dealing with the OEM zipper for years was enough to make me want to avoid even having one. I was willing to give up the "flow-through" ventilation of driving with the top up and the window down. I think I did that less than a dozen times since I got the car in '91. I also like the idea of being able to put the top down in seconds just by opening the latches and lowering it. This top requires a slight modification of the frame to locate the rear bow using nylon straps, which tie to the rain rail retainer bolts. The rear two bows no longer have listings inserted into them. My understanding is that this top is similar in function to the M2 top.
I reviewed the instructions on Miata.net and am grateful for both Brian Dore's and Chris Lambert's work. From what I read, Robbins has apparently greatly improved their instructions with this new version top. There are probably close to 40 small pictures, each with instructions. I followed them, using Chris Lambert's instructions for shortcuts and/or techniques that Robbins didn't make clear. I don't have the means to create a pictorial instruction, but I did have some observations/recommendations to make.
Since I used Chris Lambert's instructions, I will make my comments follow his numbering sequence. If I had no comment/change I will skip that number. Like Chris, I bought the top with a rain rail already installed. Also, like Chris, I did the whole replacement with the frame on the car.
4. I did not remove the carpet completely (the Robbins instructions didn't instruct me to, either) and it didn't seem to make much difference.
5. My new top did not require the frame stops to be changed, so I did not remove them.
6. Since I did not remove the carpet, I didn't need the towel (and my new window wouldn't lay flat since it didn't zip out).
7. If you have access to compressed air and pneumatic tools, a small 3/8 inch butterfly impact wrench is perfect for removing/tightening the nuts on the rain rail retainers. It can access them all except the very outside one on each side. With this top, I ended up putting these nuts on and taking them off several times, so the air tool was a real time saver. (I got it on sale for $24, but I would have paid twice that for the time it saved on this job.) Once you have the retainers out, check them for rust/corrosion. Mine needed cleaning up. I wire-brushed them and spray painted them with flat black paint. This allowed plenty of time for the paint to dry before I had to reinstall them.
9. I lowered the top completely and removed the seven screws and header bow while standing behind the car. It was not a long reach.
10. I had a heck of a time getting the two push type fasteners out of the b-pillar window seals. It was like they were glued in. I used two different forked pry tools, a flat screwdriver, and a putty knife and none of them worked very well. I think the putty knife worked best to get them started coming out, as it was the thinnest tool. I finally got them out by brute force and will power, but there was some (minor) damage to the rubber seals. There are metal tabs embedded in the rubber and they were exposed in a few places. I straightened them as best I could and re-used the seals. If I ever have leaks I can replace the parts easily or apply sealant.
11. After all that trouble getting the push fasteners out, I had no problems at all getting the dreaded b-pillar retaining clip screws out. Chris provided a very good tool recommendation. I don't have a ratcheting screwdriver like his, but used an old trick that is just as good. If you have a small, quarter-inch ratchet, pop a quarter-inch six-point socket on it. Then, a hex philips bit (or any other hex bit that you have for your drill) will fit that quarter-inch socket perfectly. You can apply pressure holding the bit into the screw easily while you ratchet the screw out. Maybe this is an excuse for you to buy a new tool ;-)
13. I drilled out all the rivets on the top (but NOT the one holding the tension cable) at this point. I then removed the screw holding the tension cable on backside of the b-pillar.
15. Based on the Robbins instructions, I never did remove the front rivet from the tension cable. I easily pulled the cable out of the old top as I removed the top, leaving the cable hanging on the frame by the front rivet. (It easily pulled through the new top at installation time, so I avoided having to drill out the plastic part on the head of the tension cable.)
16. Rivets were already removed at 13.
17. If I had to do it over again, I would simply rip the old top material right off the listings. The adhesive seemed to let go easily and then I could have gone back and removed the listings from the listing retainers without the top being in the way.
18. Cable screw was already removed at 13.
20. As I said before, the cable was not completely removed from the frame and I was able to easily thread the cable through when I laid the new top on the frame.
My comments will probably depart from Chris' here more than during removal, since I was installing a different top. There are several significant differences:
1. I didn't prop the top. The first step with this top is to velcro the #4 and #2 listings together and lay it over the top of bows 3 & 4 and then under/around bow 2. I then fished the cable through the new top (the string on the new top hooked to the spring and it easily came through). I routed the cable toward the screw and just left it hanging. Then I inserted the combined listings into the listing retainer on bow 2. I used a large pliers with many layers of tape on the jaws to tighten the retainers. This was probably overkill, but then, I am an engineer by training.
4. The bottom two rivets (the "phantom" ones) were tough. The spacing of the holes in the Robbins top didn't exactly match the holes on the bracket below/behind the b-pillar. These were the exception, for every other hole was virtually perfect. I basically brute forced the rivets into the holes at an angle and riveted them anyway. If you can get a sharp hole punch back in there safely (without damaging yourself or your new top) you could fix it that way too.
5. Not required with this top.
6. Not required with this top.
7. Not required, since I didn't remove the cable rivets.
8. Changed the sequence (following the Robbins instructions) and installed the b-pillar retainer clip here. Like Chris said, the holes are not perfect once the clip is on. Like him, I used a punch to open up the holes. The retainer/screw went in easily and I used the ratchet/bit to tighten it.
9. Changed the sequence (again following the Robbins instructions) and installed the b-pillar seal retainer, and the b-pillar window seal. The push fasteners went in with as much difficulty as they came out. I resorted to using a small brad hammer and tapping them in, which seemed to work well.
10. Now I glued the top quarter panels and front flaps to the bow. I used the adhesive Robbins specified (3M 08011) and it seemed to work well. Robbins gives the same instructions as Chris to only glue the edges. They provide good pictures of where to glue the front quarter flap and the header flap. The "quarter flap" wraps around the sides of the frame (not the front) and has a mark to locate it in reference to one of the window seal retainer screw holes. It also has a radius cut into it to locate it on the header bow itself. The front flap overlaps (and is glued on top of) the quarter flap. It can be located by aligning the 7 screw holes on the plastic retainer (which goes across the whole front) with the holes in the header. Make sure you smooth both the quarter flap and the front header flap after gluing and aligning.
11. Now install the front window seal retainers (one screw goes through the quarter flap). Install the window seals and the two screws in each one.
13. With this top, I had to put 13 foam seals over the studs before I pushed the rain rail onto the studs.
14. Since my top has no zipper, the window doesn't need to be propped out of the way.
15. After putting the foam seals and rain rail on the studs, I used my air tool to drive the nuts onto the studs and push the seals/rain rail as far on as possible (without the retainers). Then I removed the nuts and put the 13 inner foam seals on the studs. Then I put the center retainer on and drove the nuts on to seat it all again. I took the nuts and retainer off the center rail and repeated with the two outer rails. I think this is the only way I could have gotten all that material to compress onto the studs. After this, I pulled the lip on the outside molding out. (See Chris's step 16) I don't know that I could pull it out with the rain rail retainers in place. Then, I tried to place the straps (for bows 3 & 4) over the outside studs where the center rain rail retainer would go. The holes were too small. You can use a punch to enlarge them. Or, another way that leaves a non-fraying edge is to use heat. To make them larger, clamp a large nail in a vise-grip plier. Heat the pointed end of the nail with a propane torch (for God's sake, keep the torch OUTSIDE the car) and use the hot nail to melt the hole larger. IF YOU USE THIS METHOD, KEEP THE HOT NAIL AWAY FROM YOUR TOP!!!! Make sure you get "left" and "right" correct. Hold them up like they would be installed and check the angle of the sewing of the short piece at the top. It seemed best to me that the angle should go away from the center of the car with the strap over the rain rail stud and pulled tight. I pushed the center retainer onto one outside stud and started the nut. I tightened it (so the outside retainer would fit) then worked my way across, only tightening the nuts enough to start the next nut. When I got to the other end, I tightened the end nut (again, so the outside retainer would fit). I then loosened all the nuts except the outside ones. I then placed the outside retainers on and pushed to get the rear-most nut started. I tightened that one to help me get the next ones started. I then worked my way to the fronts of the side retainers, putting the nuts on and tightening only enough to get the next one on. After all the nuts were on, I loosened them all, including the end ones on the center rails.
16. I checked the lip to make sure it was "up".
17. I tightened the nuts in the sequence Robbins recommended. For the life of me, for how hard it all went on, I am not sure what difference it could make.
19. My new top did not require a spacer below the frame stop.
Insert new step here: I now had to rivet the other ends of the straps that are tied to the rain rail retainers. Lower the top. You may have to guide the window down and help bows 3 & 4 retract. (That is what the straps will do when they're on.) The straps go over the tops of the bows. The double-sewn end goes into the retainer of bow 4 where you drilled the holes. The single end goes into the retainer of bow 3, where those holes were drilled. There are no holes in the straps for the rivets. You may want to punch the holes or use the hot nail method again. If you use the nail method, you can put the straps in the retainers, crimp them in place, and then melt the holes through. Then the rivets can be placed without removing the straps. WARNING AGAIN!!! IF YOU USE THIS METHOD: KEEP THE HOT NAIL AWAY FROM YOUR TOP!!!
20. I did not loosen the adjustment on my latches. I was able to force the top into place and latch it without adjusting. I left it for about 30 hours and it now works perfectly without any adjustment. I was maybe just lucky.
I checked the fit after latching. It was so tight it sounded like a drum. There were absolutely NO pulls or sags around the header (or anywhere, for that matter). I may have just been lucky or maybe the cloth top is not susceptible to this.
I love the top. The black cloth looks SO rich and dark. It really looks great against red (is there any other color Miata?) It made my seats look gray, so I ordered new seatcovers ;-) And I love having glass. The visibility makes driving safer. I also love the way the top folds without a zipper. I can actually put the top up/down on the freeway during a momentary stop during rush hour traffic. It's literally a three-second operation.
Again, thanks to all those who've gone before and created such great instructions (especially Chris Lambert) and I hope these add just a bit to that body of knowledge.
27 July, 2003