Alignment Bolts

[Magpie]

Had an issue on the day of leaving for the MX5 Fan Fest, the 4 spare alignment bolts I had ready to install were missing the nuts and washers. Whilst this may not have been an issue the 4 bolts that were being replaced were NA type, whereas my spares were NB's.

The NA alignment bolts have a different pitch AND the washers are a different type.... A quick trip to Automotive Plus and Dave helped me out as Mazda had non in stock (in Australia).

It was not just 1 bolt that was stuffed, there was also 3 stuffed washers, this also explains why the rear alignment would not stay as it was set. Final alignment was -3°56" in the front and -3°15" in the rear with -3mm total toe in the front and +3.2 in the rear. If you live on the West side of Brisbane give TTS a try, well worth it!

DSCN3975 by Eipeip, on Flickr

DSCN3976 by Eipeip, on Flickr

NA & NB alignment bolts
DSCN3980 by Eipeip, on Flickr

TTS https://www.facebook.com/TTSTyreandAuto/
IMG_1594[1] by Eipeip, on Flickr

[ManiacLachy]

Mazda changed the design of the bolts and washers at some point, the old ones we especially prone to slipping.

I have a box of new ones ready to go for when I change out my bushings. Even though mine should be the new design they've worked hard these past 12 years. Also, the spare set of control arms I bought have a set too.

[Luke]

There you go, I didn't know NA's had different bolts.
My NB SE definitely has the newer design. No surprise being the end of the run for NB's.

My plan appeared to be the exact opposite of yours, mine was to change everything upon returning from Fan Fest which I am in the process of right now.
I didn't want to wear out new parts on the way down and back which ended up being a good choice with my route planner putting us on goat tracks and dirt roads.

I recently bought 8 new bolts, washers and nuts as well as control arm bushings as mine are all well used. All were still original. The front lower control arm bushings had already slipped by about 6mm cutting the lip off them as well. The rear bushings still looked good when they came out today. The fronts had some minor tears in the centre.
My alignments have not been holding well with the current bolts and I could feel why when removing the arms this Monday. The bolt threads felt sandy and stretched and the washers are well worn with the holes elongated and chunked out much like your pics.

At about $90 for all 8 bolts, washers and nuts I might make it a once very 10000km job to change them out after seeing the wear on them.

[StillIC]

I wonder whether these washers became damaged during the bolt tightening process.

During bolt tightening, it is important to hold the bolt head in place with one spanner and tighten the nut with a second, whilst keeping an eye on the washer under the nut to ensure it doesn't turn relative to the bolt. Not easy to do and another thing I dislike about MX5s. Now that I think about it, next time I do this job I may grease between the nut and washer to minimise the risk of this issue occurring.

Perhaps there is an opportunity/challenge to design a replacement camber device for standard A arms??

[Tony]

Something like this:

https://www.flyinmiata.com/eccentric-lock.html

[StillIC]

Nice find Tony.

US$13 each seems expensive for two simple pieces of metal. That'll be about ~AU$140+postage for one car's worth. I reckon they'd be easy to copy and have laser cut locally for a much lower price for 2 or more cars worth of them.

Right, looks like I have another project, but this one should be simple.

[NitroDann]

I think they need to be stamped to be cost effective.

I looked into this, they aren't just mild steel they are very tough.

Dann

[Mr Morlock]

metal stamping possible or even a die casting. In any event you have to make tooling and the tooling is amortised over the estimated volume. Low volume stuff can get very exxy.

[madjak]

If people are interested I could make up some fixed washer sets in increments. It would mean a bit more manual time switching settings but it means they can't slip and you could run higher grade bolts without the flats.

They would be easy enough to get laser cut from 3mm steel. I'd guess at around $3 a washer.

[StillIC]

I am suggesting copying the variable design. The laser cutting would be cheaper overall than fixed increment washers.

The steel would not need to be 'toughened'. Any reasonable cold rolled steel is good enough for this application I believe. And if the teeth break, well, it will revert to being no worse than the standard arrangement, and you could see the breakage. They would not need to be stamped to be cheaper than AU$18+postage from the USA. Laser cutting is pretty cheap these days, if you know where to go. My two favourite laser cutters are:
http://www.acuform.com.au/
http://www.hydrolasercut.com.au/

Edit: I don't believe that going to a higher grade bolt is necessarily advantageous, as the tube in the bush is not as strong as a higher grade bolt and could crush under maximum tension. I haven't looked at its cross sectional area, but it would be worth analysing.

[madjak]

I don't like copying a design if there is a vendor already selling them. Not fair on them in my opinion even if the pricing is a little high. There was most likely a lot of development costs to get them right and FM are charging enough to make it worth selling them in what would be a limited market.

Change the design and it's not an issue.

[madjak]

I run chrome moly sleaves and crank my concetrics bolts up so tight I'm worried about popping one. I use a long breaker arm and lots of effort. A higher grade bolt would be nice.

With the fixed washers though they wouldn't need to be cranked up so tight.

[StillIC]

I don't like copying a design if there is a vendor already selling them. Not fair on them in my opinion even if the pricing is a little high. There was most likely a lot of development costs to get them right and FM are charging enough to make it worth selling them in what would be a limited market.

Change the design and it's not an issue.

If the vendor wasn't on the other side of the world and charging an arm and a leg, I might empathise. Plus, I take a socialist approach to designs that aren't patented/patentable.

I wouldn't change a design just so it's different, if it is no better than the original. Seems like a waste of time and an insult to the original designer.

PS: I am thinking of copying your bush design ;)

[madjak]

I consider everything I post on the forums open source so I'm happy for any individual to copy it. Realistically, anyone individually can copy a design as long as they dont start selling or distributing. Legally they are on the edge but noone will procecute. Its more an ethical / moral issue for me.

As a designer though I'll happy use ideas from others but generally try to avoid directly copying a design. In most cases there are small improvements that can be made so its different enough that I'm happy. When I have directly copied a few designs, like the singular end plates on my wing, but I emailed them and asked permission before I did.

In this case FM has made a fairly elegant design which they are selling. If you go and make these yourself then you're not going to save much especially given the number of iterations to get them correct. Its not really worth the effort to be honest but I doubt there would be any issues if you did.

What I don't think is right is going out and making 10 sets and sending them out to others even if you're not making money off them. Sure they probably would be cheaper as a batch, but you are definitely on the wrong side of the law and I think ethically bad especially given we are all MX5 / miata enthusiasts.

[madjak]

Btw, Paco Motorsports make the eccentrc locks not FM. They sell a set of 8 for $100US. I'm sure they would be happy to do a group buy.