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Mazda MX5 NB, Get Ya Top Off

I’d had enough of the horrible, leaky, torn and ugly soft top on the car, so it was time to pull it off.

I had originally intended to repair the soft top, by pulling out all the sealant holding the seals in, fitting them correctly and then replacing the tension cable that is broken. Unfortunately after I purchased the new tension cable I made the call to scrap the roof, it was just too far gone. The vinyl is rock hard and cracking, and many of the seams are pulled to bits from opening the roof with the sealant on it (it pulls on the wrong places when it opens).

With this in mind I did some digging. I tried to find and purchase a good condition NB top with heated glass (like I have originally) but they are hard to find, and new ones are way more than I want to spend on the car. With further investigation I found you can apparently use an NA soft top on an NB, as long as you use the complete frame. NA soft tops are easier to get hold of, but you lose the heated glass window and instead get a larger, zip out plastic window.

I managed to find a seller on Trademe that had a good condition NA soft top with frame off his race car (didn’t fit over his roll cage, so went hard top), and it was fairly local and well priced. I arranged a time to head out and have a look. It turned out to be good enough that I purchased it on the spot, and the seller even threw in the mint condition rain rail too. There is a small patch just behind the driver’s door, but otherwise the top is in minty condition, and the window was replaced a couple of years ago so is clear as clear can be. Winning.

Removing the soft top in an MX5 isn’t rocket science, it’s just bit of a faff.

First things first, the seats have to come out. I started with just the passenger’s seat, but ended up taking the drivers one out too. Some nice mismatched bolts.

The driver’s seat was even missing a bolt >_<

Super limited space behind the seats, so rattle gun with long extension was my best friend here. I really need to get a long impact extension (and use my impact sockets instead of my Fuller Pro sockets).

With the seats out its time to start taking out the trim. This flap of trim is usually secured with a bunch of clips, but someone had broken the heads on all but one of mine

To remove the side trim, you need to first remove the top seatbelt bolt. This will be super tight (as it should be), and it has a spacer under the belt mount, don’t lose it.

Then the wind blocker needs to come out. There are two screws on each end, with the top one of them also being a snap for the tonneau cover, if fitted

Now one of the fun parts. You need the top up, and to lean over the rear panel to remove all the push fasteners holding the carpet in. I tried a few different tools, but in the end I found a trim removal tool like the second from the left in this photo to be the best. You slip the fork under the head of it, and give the end a quick sharp whack and it pops the clip out in one go. You can’t be gentle or slow removing these clips.

Before you can remove the carpet there are also two rubber stops that need to be removed. The are hidden behind where the seatbelt bolts in. It’s hard to see, but is just screwed in.

because I have a heated window I needed to disconnect the heater element to the glass too. The plugs are hidden in this fold of fabric

Carpet out

To remove the retaining plates, you need to remove all 13 10mm nuts. Be careful with the side ones so you don’t drop one down into the abyss, never to be seen again. To remove the plates you MUST remove the side ones first, or the center one won’t come out. I found using a rattle gun with a long extension, again, made removing the nuts so much easier.

And then you can see the rain rail

You can then carefully remove the rain rail and top from the studs. In the case of mine my rain rail was so brittle that it cracked in a couple of places upon removal. It also wasnt riveted to the top like it should have been originally. Not a major, im not reusing it.

To remove the top completely, you need to fold it down, and remove the three bolts on each side

Then it can be lifted off, if you have a helper; or if you don’t, it can be rolled over onto the boot. It’s not really heavy, just bulky and awkward.

Since the top was off it was a good time to check the drain holes for the top.

This one isn’t too bad, although there was some rubbish sitting in the tray ready to block the hole. The drain holes are next to where the top seat belt bolt is. If you look at the bolt, and then look in the gap between that and the outer body of the car, its down there.

The other one was half blocked

Using a length of firm wire (sourced from the engine bay originally) I wrapped the end in tape to make sure it wouldn’t catch anything, and then fed it into the drain

It, and a bunch of dirt and rubbish, came out the bottom

I did this to both drains, and then using a dust buster, I vacuumed up the rest of the muck

You can also see in the above photos some rust converter here and there. The moisture from the leaking roof had caused some rusting in places, So I ground it back, treated and painted it (only had silver zinc paint, but it’s hidden anyway)

I also had to grind out and treat some rust on the retainers. Leaking roofs are no bloody good.

With the top off the car I chose this time to take a break, and clean some seats, since they were already out of the car and well, pretty grotty.

The driver’s seat is apparently red, but I don’t think its been red in a long time

If anyone ever replies with “waterblaster” when you ask how to clean your seats, I’m here to tell you that it is the CORRECT answer.

This is what I was dealing with…

After lots and lots of water blasting, and then sucking the water back out with my Little Green Machine, the seat was red again. It took a couple of days of sitting in the sun, and then sitting by the dehumidifier to dry it out

I then moved onto the, not too dirty looking, passengers seat…. and wanted to be sick.

I didn’t waterblast this, but just used the Little Green to spray on a cleaning solution and then suck it back out again.

I don’t know, or want to know, what it was, but the whole front RH side of the seat was giving out a yellowy brown liquid when cleaned. I got it as clean as I could be bothered. It could do with a more thorough clean, but I got the worst out.

So with the seats nice and clean, over the next few days I worked on getting the replacement roof on.

A couple of quick tips.

PLAN your attack. It’s a shitty job at best, but worse if you have to do it twice (or more). It’ll ruin your back.
DONT do the job in shorts without a cushion to kneel on, it’ll ruin your knees.
Climbing in and out of the car over and over will make you want to rage.

So, putting the roof its self back on isn’t hard, with two people (many thanks to my long-suffering wife helping me for “two minutes” before bed). The trick here is to install the roof in an open position, or the side studs and bolt holes don’t line up

Roof on

I did swap latches too. The NA latches appeared to fit and operate as expected but they were worn, and my NB latches work perfectly. The NB latches swapped straight over to the NA frame. The NA latches have a cute little “UNLOCK” text that the NB doesn’t have. I did also note that the unlocking tab is different between NA and NB, and the ones I 3D printed a while back look a lot more like the NA tabs.

Replacement rain rail in. I found leaving the rain rail in the sun for a few minutes helped to soften the plastic and rubber, and made it easier to get into place without risking breakage.

Now this is where I had already gone wrong. I proceeded from here to install the top into the rail, fit the retainer, and then leak test. It leaked from behind the rain rail.

This is where I went back to square one, and fixed a couple of things I initially thought were odd but dismissed them.

First I used duct tape on the rivet holes on both sides of the rain rail. My top isnt riveted to it, so in theory these are just holes waiting for water to go through

Next I made some seals for the studs out of a thin plastic foam I found at work. I used one on each stud behind the rain rail; between the rail and the body

and then again on each stud between the rain rail and the retaining plates (not between the retaining plates and the nuts as shown below, the nuts shred the foam)

This makes a sandwich of Body/foam/outer rail/top/inner rail/foam/retainer/nut. The nut compresses the foam into the gap in the hole around the stud.

I found when installing the top into the rail that loosely fitting a nut to the stud stopped it all coming apart as you went. You need to remove the nuts later on to install the retainers. (note uncovered rivet holes, later covered with tape)

Once you have this sorted, then it’s time for the most fun part, leaning into the back to do all the nuts up. Remember, the retainers have to go in with the center in first, then the two side ones.

The nuts have to be tightened in a special pattern as per below

Since im fitting an NA top, ignore the straps, but the pattern is important.

I torqued them up with my little 1/4″ ratchet and torque thingy. It’s really bloody hard to do when leaning in the back. 85 inch lbs is a lot more force than you think when using such a small ratchet.

With the retainers on again, I did another water test. Using a watering can I poured water into the gap at the base of the top. Sure enough I heard water pouring out of the drains into the containers I had prepared earlier… and there was no water inside the car! Woot!

This confirmed that my seals and tape had done their job and the top was water tight.

Now to put the interior back together. It’s the reverse of taking it to bits, obviously.

Carpet and push pins in. Stopper waiting to go in

This little end cap is interesting. It’s a little drain to catch water that comes off the edge of the top where it meets the back of the door glass. It runs into the channel, and down into the rain rail

All the other trim went in as per removal. No tricks really.

With the seats out I had access to check something that had bugged the hell of out me since I got the car. Where was the horrible rattle in the dash coming from?

Out came the glove box.

Oh hai there random metal strap that shouldnt exist. Seems you are the source of the rattle.

I removed that, it was only held on with the one nut

I also lifted the carpet to fix one of the plastic things that hold the edge down, as it had torn off the carpet. I used a staple gun to reattach it

This was what I found under the carpet. All the wires went in the bin.

I removed the rusty metal plate over the ECU to check there was no water damage to the ECU. It all looked OK, so I rust treated the metal plate and reinstalled. Yes that black wire hanging out is for the locking actuator in the door…

Since the seats were nice and clean, I couldn’t put them on dirty carpet now, could i?

Out came the vacuum, and then in went the seats. Now with extra bolt on the rear of the driver’s seat.

And then… BAM, ROOF!

It needs a clean and condition, but already it looks a million times better than the old one. It also opens and closes so much smoother and easier. The vinyl is soft and pliable, and all the seals are properly in place. No cracking, and only one small patched tear.

The window is in dire need of a clean, but hey, why not just use the zip and open it up?

I like how the top of the window opening lines up perfectly with the roll bar. The window is huge compared to the NB top.

I look forward to testing out the new top. Hopefully having the seals installed correctly helps with some of the wind noise when the top is up too.

Winning.

In conclusion, and NA top with frame WILL work on an NB. NA and NB latches are interchangeable. Waterblasting seats works. Leaky tops making rust sucks. Roof drains MUST be checked and cleaned regularly. Rain rails can be made not to leak. And shitty cars can be saved.

 

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