mx5cartalk.com

This is about Hardtops so the HT-haters might like to skip this.
I bought a second-hand (aren't they all) HT from a Sydney outfit (that will remain nameless) in 2005. I reckon it was about 10 years old and had been on and off about 200 times. I paid top-dollar as it isn't easy to source this stuff up in the sticks.
The latches were all a bit worn but I only intended to put it on once so I wasn't real worried.
The rear latches in particular were not a very tight fit due to the two bolts that locate the 'collar' on to the Frankenstein bolt being a bit stripped from (I assume) the previous owner constantly overtightening them in an attempt to stop the top squeaking ( I tuned the squeak out long ago.)
Cleaning the car yesterday I ran the chamois close to the latch and dislodged one of the nuts - which had unscrewed itself - and was just sitting under the chrome latch on the body. Opening the latch I found that the 'collar' had moved (not surprising) and was not engaging with the Frankenstein Bolt either.
Now I am assuming that the best way to tighten these two bolts is to remove the HT, invert it, tighten the bolts, and refit it.???
Anyhow I didn't want to go to this trouble so I slackened off the Frankenstein Bolt, manoeuvered the nut back under the latch and managed to screw the bolt back down into it. (Put some pressure on the bottom of the screw by sliding a paint-scraper underneath.)
I retrospect I should have put a heap of Locktite on it as well as I feel sure it (and the other 3) will work loose again because of the constant flex of the HT.
Just curious whether any other HT users have had problems with Latches, and any insights.

Rocky wrote:Now I am assuming that the best way to tighten these two bolts is to remove the HT, invert it, tighten the bolts, and refit it.???
Just curious whether any other HT users have had problems with Latches, and any insights.

Bought my white 2000 NB8A HT in mid 2004 from a private seller in Sydney for $2k, but it was almost unused. Put it on to drive back to CBR & only took it off once briefly to check things a couple of years ago. Con65 bought a new white HT from a Mazda dealer in Dec 2012 for $3.2k. Following from the big forum might give you some ideas:
1990-2005 HT Install Guide: https://www.miata.net/garage/hardtop_inst/index.html
Installing a permanent bolt-on HT on an NA MX-5: https://www.miata.net/garage/Hardtop_Permanent/
HT FAQ: https://www.miata.net/garage/hardtop/

Hi Clubman, thanks for your trouble with the links.
I paid $1800. for mine in 2005 - it was white and it cost me another grand for a spray job.
They left the rear glass in place as they were worried about breaking it getting it out.
The very competent spray painter (who was a distant relative) asked me whether I wanted him to vary the colour on the rounded HT so it looked the same colour from all angles. I had never heard of such a thing. I said "No - I don't care".
The latches/fixings on the MX5 always seem an over-complicated and not terribly effective solution and in a soft metal as well so that repeated use produces rapid wear. Also it would have been nice if Mazda had left 'punch-outs' in the plastic trim for the side latches so that you didn't have to take a punt as to where the bolt holes were behind it. I made a real mess of that panel trying to cut holes in the plastic for the bolts.

a few notes on the hardtop.

the rear most bolts "frankenstein bolts" dont need adjustment, and from factory they are fitted with a thread locker of some form.


Any adjustment is made within the hardtop, by the latches (front and side) and via the rear catches (the nylon bits that fo under the frank bolts)


Rear adjustment is simply loosening the philips head screws on the hardtop latches, which allows them to swing out of the way to provide access to the two 10mm bolts per side for the nylon U shaped catches.


The side and front latches (with the movable arms) have a simple 10mm turnbuckle on them to tighten/loosen their grip to the latches on the car body.

Yes, that's a good summary of how it all works Kansei.
I noticed the thread-lock material on the Frankenstein Bolt.
I did loosen-off a Frankenstein Bolt about a turn as the collar didn't want to go under it's edge.
I might have another look at it and see if I can tighten it and apply some thread-locker as I think you are correct in saying that the "F" bolts are not intended to be used for adjustment.