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Fitting a Mk 1 Roadster/MX5 Top (using a Duetto hood)

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  • Fitting a Mk 1 Roadster/MX5 Top (using a Duetto hood)

    Its a fairly straight forward job if you take your time. Here's some (long) instructions I wrote up a couple of years ago for the Irish MX5 mailing list, based on my experiences fitting a Duetto hood to my car, and a standard Prestige vinyl hood to another. I've added some additional comments in red. This method is the "frame-on-car" installation. Some installers prefer to remove the frame from the car, but really to do this, you need a large clean area in which to work. Many tops now come with supplied instructions, so read these and compare to others to see which suits your circumstances best. Although these instructions are for the Duetto hood, except for minor differences, all hoods fit in an identical fashion:

    Fitting a Mk 1 Roadster/MX5 Top (using a Duetto hood)

    Tools needed:

    10-14mm sockets
    Phillips head screwdrivers (long, stubbies, original 2-headed sort found in the toolroll)
    Small, but sharp snips.
    Cordless drill. Dremel is ideal.
    Trim removal tool. Old bent metal handled fork works well
    Optional tools:
    Pop-rivet gun
    Torque drive (not essential but strongly recommended if removing the seats)
    Magnetic screw retriever.
    Sharp knife
    Materials you'll need:

    Bathroom-type silicone sealant.
    Evo contact cement (or equivalent)
    Double sided tape (sold under Duck tape brand in B&Q)
    Wire coat hanger
    Gaffer (Duck) tape.
    Dozen clothesline pegs or bulldog clips
    Isopropyl alcohol (optional)
    Permanent marker
    If working in the open, have a tarpaulin ready. It is possible to install the roof by yourself (I did it). This method took me over a weekend, with rain interruptions. You could get the whole thing done in a day. But then, there's no sense rushing this important, but satisfying, job. Only moderate technical skills are required. What is more important is a good back (there's some awkward moments) and dextrous fingers (lots of fiddly moments).

    Allowing extra time also gives you the opportunity to do jobs you would not otherwise do, such as extra waxoyling, carpet shampoo)

    Seat Removal:

    It helps a lot to remove the seats, plus it gives you somewhere to sit with the brews. Under each seat are one or more electrical connectors for the headrest speakers (if fitted) and seatbelt sensor. Disconnect each connector. Unscrew the four bolts that hold the seat runners to the floor.

    Immediately after removing each seat, put the bolt, washers and brackets back in their original order on the seat and tape them in place so that you won't forget the order in which they go back together. The tops of the bolts are flanged; and ordinary 14mm socket may round these off; get a 6-sided impact socket if possible. You will need a breaker bar for these, as the bolts (especially the rearward ones) may be very stiff. On 1.8 models, the seatbelt buckle is attached to the seat frame, so an extra bolt has to be removed from the transmission tunnel.

    Top Removal:

    Deep breath now, time to remove the old top. You are unlikely to be able to put it back on again.

    I used a steel fork with the 2 central prongs bent to pry up the black plastic tabs on the rear deck that hold down the carpet. These tabs break very easily so take your time. They are resilient suckers, and will bend the fork. If they break, you can get slightly smaller replacements from Halfords. The carpet is retained by tabs running along the edges, 1 on the flat centre, and by 2 screw fittings. Carefully store the clips in a box.

    Once the tabs are all removed, pulling back the carpeting will reveal the rain rail retainer bars (the three black metal bars that run along the bottom edge of the top). Remove the securing nuts using a 10mm socket, then remove the bars from the car. Label each bar.

    On either end of the rain rail is another black plastic tab. Some cars will also have a screw on each end of the rain rail as well. This tab is extremely difficult to see; and I only saw it much later. It is located in the far corners behind the seatbelt towers, and is very difficult to remove. I decided to simply snip the head of the tab; a replacement tab is easy, a new rain rail is not (but the rain rail is not as fragile as you might think). As you remove screws and bolts it's a good idea to loosely thread each one back in its place so you don't lose it or forget where it belongs. Fold down the top. On the underside of the front lip of the top frame is a retaining bar that runs across the width. Remove the screws from the bar (marking the bar's position), then remove the bar, label it and set it aside. Next, remove the two screws on either front corner of the top that hold on the rubber corner seals.

    Put the top back up without latching it. On each side of the car, remove the three pieces of rubber seals that seal around the door windows. These pieces are held in by a pressure fit and should pull off easily. The bottom of the piece that seals around the rear of the window is also held in by two plastic tabs (similar to the ones that hold in the carpeting on the rear deck). To access these tabs, fold the top down. I found it impossible to remove these tabs, and ended up breaking them off. They are not too vital however. Label the seals; its especially easy to mix up the 2 central ones.

    Removing the seal will expose screws underneath that hold in the aluminium seal retainers. Use a marker to trace a tight circle around each screw head on each retainer. This will allow you to reinstall the pieces in their exact original positions, avoiding the need for readjustment. Number each of the retainers to match the seal pieces you just labelled. Remove the screws and the three aluminium seal retainers on each side of the car.

    On the lower "elbow" hinge of the top frame, where you removed the two plastic tabs that held on the bottom of rubber seal piece #3, (the area of the car commonly referred to as the "B Pillar"), you'll see the B-Pillar Retainer (also called the Binding Guard), a small black retaining clip held in by a single screw. Very early MX-5s/Roadsters did not come with B-Pillar Retainers. They protect the top binding from wear. The B-Pillar Retainers are recessed in the cavity between the body and the interior of the car, so to get at this screw you'll need a right-angle Phillips screwdriver or a mini-ratcheting right angle Phillips screwdriver. I found that the black double headed screwdriver found in the boot tool roll worked well. You can't quite get enough purchase using a stubbie screwdriver. Remove the screw and the B-Pillar Retainer from each side of the top and set them aside. Carefully label them, and note how they fitted.

    Under the area where you removed the aluminium seal retainer closest to the rear of the car you'll see two rivets on the folded top frame. Using a ¼" size drill, drill out the rivets (Dremel bit works).

    Running though each side of the top is a spring-mounted tensioning cable. The cable is riveted in place at one end and attached to the top frame at the other with a screw near the B-Pillar. If you raise the top about 1/3 of the way, you'll have access to the screw. You might have to pull a bit at the top to gain access. Remove the screw, and from the riveted end, pull the cable through and out of the top. Note how the cable passes through the hole in the top frame, later you'll need to reinstall the cable and spring exactly the same way as it was before disassembly. Other methods talk of drilling out the riveted end of the cable instead. Carefully remove the spring off the end of the cable, and pull the cable through.

    Put the top about ¾ of the way up. You can support the top with a cardboard box or cushion between the front of the top and the windshield frame. The next step is to remove the top material from the bows (the three horizontal metal bars where the top material attaches to the inside of the top). Each bow consists of a rigid bar with a pliable metal strip running alongside it that clamps the top material to the bow. Pull the top fabric back from the front of the car till you reach the first bow. Using your fingers, gently pry the pliable metal portion of the bow back just so that it releases it's grip on the top material. Repeat this for each of the three bows. Its quite flexible; be careful you don't bend it too far, but you need a bit of space to reinstall the new bows. The rear bow also has a Velcro wrap around it that will need to be opened.

    Stand behind the car. To the outside of each seatbelt tower are two rivets that attach a flap of top material to a fragile bracket. You can try drilling out these rivets, but I found it a lot easier to just cut the fabric off and drill out the rivets later (the old top is probably only fit for the tip anyhow).

    The top should now be completely free from the frame. Although the top is probably headed for the trash, when lifting it off the car you'll still need to be very careful not to damage the rain rail. If your rain rail is brittle it may develop cracks if flexed, so try to keep it in its original shape as you remove it. If you do see cracks in your rain rail don't worry too much, we'll repair them later. In almost all cases the rain rail is repairable. If your rain rail is severely cracked or broken all the way through you'll most likely need to purchase a new one before you can continue. However, the rain rail is not quite as fragile as you might think; it looks like a piece of guttering; the inner part is the fragile bit, made of the same sort of plastic you find in a box of milk tray, the out part is rubber and quite flexible. The whole thing will flex some, so don't be too afraid at levering it out off the studs.

    Stripping the rain rail.

    With the old roof now on your lawn, separate the rain rail from the top by cutting out the rivets with a pair of sharp pincers. I found the wire cutters on a crimping tool to work well (these are not like normal rivets and are quite tough). Do not try to drill out the rivets or they'll spin and burn holes though the rain rail, making it unusable or difficult to repair. By using a pair of sharp, thin side-cutters you should be able to snip the shank of each rivet. Take extra care not to cut into the rain rail itself. I found cutting the shank of the rivet on the rubber side of the rain rail work best. Work from the centre out. You might find some of the rivets pull through the rain rail, particularly on the fragile bit; don't worry too much about this.

    Trying to cut off the heads of the rivets as opposed to cutting the shanks makes it more likely that you'll cut into the rain rail and damage it. As you remove the rain rail, pay attention to how the top and rear window curtain fit between the layers of the rain rail, so that you understand how to reinstall it.

    When finished, discard the old top and set the rain rail aside in a large clean space free of any debris or rough surfaces (the cardboard box the top came in is useful for this). Tape paper over the front and back of the window to protect it during installation. Nothing worse than scratching your new rear window while putting it on.

    I didn't bother re-riveting the rain rail to the new hood; its not really necessary, and as pop rivets aren't really the same as the originals, I suspect your rain rail won't be watertight like the original, unless you went around and additionally sealed each hole. Some people report that fitting the roof with the rain rail already attached is easier, but I disagree. I fitted the hood to the rain rail, while the rain rail was fitted to the car, and found it perfectly straight forward.

    (Prestige Hoods, and maybe others, are supplied with a trimmer's larger sized rivet to replace these. I'm not sure if these can be used in the common pop-riveter)

    Roof Installation

    The Rivetless Rain Rail Method offers the advantage of better adjustment of the top after installation (if necessary), plus if you ever need to replace your rear window you won't have to deal with cutting rivets out of the rain rail all over again. If you rivet the rain rail on, and get the fabric slightly out, you'll be stuck with wrinkles that'll never come out (the rain rail was riveted in the factory to ease assembly, nothing more).

    Clean the area around each rivet hole with alcohol. Using the gaffer tape to seal the old pop-rivet holes on both the inside and outside of the rain rail. Don't tape over any bolt holes. Seal any cracks in both layers of the rain rail with silicone. I also filled in the holes with silicone sealant. Don't worry too much about being neat; the rain rail isn't visible when installed. But it is important to make sure that you don't make the silicone repairs too thick or they could interfere with the water sealing function of the rain rail. Ideally let the silicone set overnight before fitting the rail on the car.

    Fit the rain rail into the car on the studs, making sure the rubber lip is properly in place.

    The bolt holes on the new top come pre-perforated, but will sometimes need to be popped out with your fingers or a small screwdriver. I found these all to be perfectly aligned. (not the case everytime. Prestige hoods need a bit of persuasion)

    Place the outer layer of the rain rail on the studs on the rear deck of the car. Be sure the outer top edge of the rain rail goes under the rubber lip on the body of the car. You can then fit the top onto the rain rail studs, followed by the inner layer of the rail-in other words, the top material should go between the two layers of the rain rail, and the studs should pass through them all. Important -On the side quarter panels of the top, be sure that both the outside layer of the top as well as the inner window curtain layer are placed between the inner and outer layers of the rain rail. I worked my way out from the centre stud, putting on a nut very loosely onto each stud when I was done, ensuring the top didn't come off the studs.

    When completed, you should have a sandwich of a total of four layers of rain rail and top on each end and three layers in the centre below the window.

    Starting with the centre section, remove the nuts you used to hold things together temporarily and place the centre retainer bar in position. You can then finger-tighten the nuts to hold down the retainer bar. On each end of the rain rail, replace the plastic tab and screw (if removed), then replace the side retainer bars using the same method used with the centre bar.

    Put the top up 3/4 of the way. If you have the double-sided tape(optional), adhere a strip across the underside of the front of the top lip of the frame, above the screw holes. You might need to trim the edge a bit. Don't remove the peel-off outside covering of the tape yet. This tape is just temporary, as I'll explain later.

    (There are usually flaps on the "B" post of the hood, which need to be fitted around the frame. They may be easier to fit before attaching the front bow. In some hoods, it maybe necessary to remove the frame from the car, and then fit the hood, with the frame upside down)

    On the front edge of the new top is a black plastic strip with pre-punched screw holes. Bring this strip over the front edge of the top frame, and line up the holes on the black plastic strip with the holes in the frame. This plastic strip needs to be folded up so that the vinyl covers it; you need to locate the pre-made holes through the vinyl with a punch or sharp knife. If using a knife, make only small vertical cuts; the vinyl is less likely to tear. Make sure the front seam of the top aligns with the front edge of the frame. Replace the metal retainer bar and screw it down. Be careful not to over-tighten the screws. Important-check your markings and make sure the retainer bar is replaced in it's original position and orientation. Now that you are happy about how the front goes together, take it all off, and remove the backing paper from the tape then press the top fabric firmly into place, making sure it is smooth and that no sections are bunched up. The tape is left on a week to allow the vinyl to stretch a bit. Later on, its easy to remove, and replace with contact cement for permanent adhesion. If you try and glue it at this stage, you might find with the vinyl stretching, wrinkles will develop. When gluing with the contact cement, be sure to follow the instructions; coat both surfaces and let dry to tack-dry. Use the pegs/bulldog clips to hold the fabric in place for a while.

    (Every Mazda hood I have removed has used some sort of adhesive on the front rail; usually the stuff that remains sticky. It may not be necessary to use glue. If in doubt, you can leave it off, and apply later)

    Straighten out a coat hanger and fashion a small loop on the end, making sure there are no sharp edges. Use the coat hanger to pull the side cable through the sewn-in channel on the new top, taking care not to snag anything on the top material. Be sure the spring and cable are threaded through the hole in the top frame the same as they were before disassembly. By moving the top frame up or down, line up the screw hole with the cable end and screw the cable back onto the top frame. This will require a bit of pulling as you are working against the tension of the spring. I found the best way was to tape the screw to the screwdriver, put it through the end of the spring and pull down. It also helps to block up the drainholes behind the seatbelt towers with some paper or rags. Screws, nuts etc. invariably get lost in this area. If they drop down the drain holes, they don't necessarily fall through onto the drive. More often than not, the plastic baffle in the drain catches them. If this happens, you need a telescopic magnet to fetch them out.

    Put the top up but don't latch it. Now go to the area where you earlier drilled out two rivets that were underneath aluminium seal retainer #3 on the sides of the top behind the side windows. Your new top has a flap on each side that attaches to the frame at this point. There's a black plastic strip sewn onto the edge of this flap that has pre-punched holes. Fold this strip over and punch through the top material itself using the holes on the plastic strip as a guide (this is the only place where a pre-perforated strip will be doubled over the top material before being screwed down). By folding the strip over, the top material will draw snug to the frame.

    Since the aluminium seal retainer will later be screwed down over this section of the frame and can effectively secure the top as well as the rivets, you can skip replacing these rivets if you like and continue on to the next step. If you want to reinstall the top exactly as it was when it came from the factory, then rivet this flap down before continuing on. Make sure before riveting that all the screw holes in the frame line up with the pre-punched holes on the flap.

    After your holes are punched and your rivets (if you choose to use them) are in place, replace and screw down the rearmost aluminium seal retainer. To install each aluminium retainer in its original position, centre the screw heads in the circles you marked earlier and tighten down the screws.

    On each side, replace the B-pillar Retainer and screw that you removed earlier. The U-shaped section of the retainer should fit around the front edge of the top binding. Don't worry if you now have a space between this U-shaped section and the binding. This is a bit tricky to fit; I had a serious attack of "which way does this fit"-syndrome.

    Next attach the front corner side flaps of the top. Pull the flap snug and place it between the top frame and aluminium seal clip. Using the awl, carefully push through the screw hole in the seal retainer, punching through the flap and into the screw hole in the frame underneath. You want to get it so the edge of the roof is roughly straight. Don't worry about the flap of vinyl that hangs in the car; it can be trimmed off later. Loosely screw the aluminium retainer bar in place. The remaining section of this aluminium seal retainer attaches directly to the frame but does not pass through any top material. Centre the screw heads in your circle marks and tighten them down. Replace middle aluminium seal retainer on each side.

    Next secure the front corners of the top. Each corner is held down by two screws which also retain the front edge of rubber seal. At this point, don't glue it down. Since the fit of your new top will at first be very tight, if you apply the adhesive during the initial installation it may not hold or may cause wrinkling. I let the roof stretch for a week before gluing the front edge down. To apply the adhesive at a later date, all you need to do is remove the two screws holding the front edge of the seal down and apply the adhesive. Apply adhesive only on the underside of the front lip of the top frame where it is hidden when the top is closed. If you use adhesive under any part of the material that is visible when the top is up, you may get uneven spots where the top is adhered to the frame. Since the adhesive will be permanent, be sure that the top is smooth and has no wrinkles or bunching before gluing it down.

    Pull the front corner of the top material evenly and snugly over the frame making sure that the front seam is even all the way across without any wrinkling or bunching on the portion of the top that will be visible when the top is closed. Note the location of the two screw holes in the frame.

    If there is an extra length of binding material, lay it between the two screw holes as you make the fold. Once the corner has been folded properly, use your awl to punch the outermost screw hole. Screw down the front corner of rubber seal #1 into the two screw holes.

    The remainder of the seal attaches back onto the aluminium retainer with a pressure fit. Squeeze the rubber together and press it into the retainer until the grooves in the rubber are properly seated. Press in the other rubber seal pieces as well. At the base of rubber seal #3, replace the two plastic tabs that pass through the holes in the B-Pillar Retainer.

    Tighten the rear retainer bars now on the rain rail (at this point you might want to make any adjustments in the fit of the roof). Follow the sequence below. The workshop manual gives a torque setting of 78-104 inch/lb. Most long handled torque drives won't be able to turn in the space you have unless you have a very long extension. I just carefully tightened them down "tight". Don't over-tighten, or you could snap a stud off.

    Now attach the top to the bows. Corresponding to each of the three bows on the top frame is a flap of material with a black plastic strip sewn on the end. With the top up (but not latched), wrap the flap around the foremost bow, push the plastic strip into the pliable metal channel and press the channel closed so that it snugly and evenly holds the strip in place. Repeat for the centre bow, and then the rear. The rearmost bow also has a Velcro wrap that closes over the bow. (These should fit snugly, and the frame must grip the material effectively. The Prestige hood I fitted had about 2" too much material on the bows, and this had to be cut off)

    The next step is closing the top for the first time. At first the top will be next to impossible to close--it'll take two people and even then it may be a struggle. I found the new top slackened off quite quickly; after an hour or so I had to retighten the latches a bit. Always push or pull only on the metal frame.

    If you really can't close your top, you can temporarily adjust the latches to gain some additional clearance. Open the latch fully. On the underside of the latch is a small plastic piece that covers the adjuster nut. Flip this cover piece up and turn the adjuster nut clockwise to loosen the latch. Make a note of how far you turn the adjuster nut so that you can return it to it's original position when you need to. Readjust your latches once the top has stretched or you may get leaks and rattles.

    Leave the top closed for several days until it stretches out and conforms to the car; after that it should open and close more normally. It's OK to open the top before it's stretched out, but just remember it may take two people to close it again.

    You may also find the window zipper very difficult to open and close the first week or so; it should also loosen up after a few days. It's normal for the rear quarter panels of the top to be a little loose.

    If they seem overly loose, you can loosen the nuts on the three rain rail retainers and adjust the top a bit. Once you're happy with the tautness of the top, re-torque all the nuts on the rain rail retaining bars in the proper order.

    Check for any leaks (watering can over the rear), and then replace the rear deck carpeting and snap the black plastic tabs back into place. You can pop-rivet the two inner flaps back onto the brackets near the seatbelt towers, where you removed them earlier, but I found it easier to attach them with a short self tapper each side. (Later I was able to borrow a heavy duty 360-degree rivet gun to do these properly, but I was only able to get a good rivet by removing the frame and top from the car)

    Check and tighten down all screws all around the top frame. Be careful not to over-tighten.

    If you removed the seats, reinstall them in the reverse order of removal, taking care to reattach the seat and seatbelt buckle assemblies exactly as they were before removal. Torque the four bolts that hold down each seat rail to 28-38 ft/lbs. (or 38-51 Nm). Reattach the electrical connectors under the seat.

    You might find you have to slightly adjust the side seals a little; they may well have been reset at some time to try and cope with a shrinking top. With the Duetto top, you also get a large sheet of scrap vinyl (well I did); use this, or pieces from your old hood to reinforce the parts of the lining that contact the frame (if you look at your old hood, almost invariably you will find that the frame has worn parts of the lining).
    OutlawJapClub Admin Team

  • #2
    Good detailed write up! Should be useful

    Sent from my iPad using Tapatalk
    OutlawJapClub Admin Team


    • #3
      Yeah will help someone I hope

      Sent from my iPhone using Tapatalk
      OutlawJapClub Admin Team


      • #4
        I very nearly went for an MX5 instead of the Lexus.