Mazda and their cheap plastic Undertray Fasteners
 

I am sure this has been sworn upon a LOT my FD owners, but for the Newbies out there, removing the undray is easy, until you realize the cheap brittle plastic fasteners won't pop out. There are three of them. If you can spinn out the centers I discovers I can force the fasteners out by destroying them without hurting the tray.

BTW, any one know if Mazda upgraded these if I replace them? I would hate to put crappy plastice undertray fasteners back in again to have this happen yet again....

I never really seen new designs for the fasteners but I heve seen one thats pretty good sold at a place in California at a bike shop called Chaparral. They have a plastic rivet fastener that has three stages. 1st is the open position which allows you to insert into the hole. 2nd stage when it's pushed in flush with the head it locks into place. The best bart is the 3rd stage that when you push the rivet further into the housing it becomes open again and you can easily remove it without damage to the part its holding and its reusable!

Which fasteners are you talking about? The belly pan is primarily held in with 10mm bolts. There are 2 plastic fasteners I think that hold it in stock in the back corners, but both of those are almost always gone - I've never actually seen them on an FD.

The plastic clips that hold the brake ducts and fender liners have the Phillips head screw in the middle - those can be a pain sometimes. I try and load up on them at the junkyard. Usually if you put pressure on the surround and gently unscrew the fastener it will come out.

Dale

Heh... Well i have an incredibly virgin FD (35K original miles) and those darn fasteners were a PITA to get out. There are 3 all together, 2 in the rear near the frame, and one in the front center. These are the ones with the phillips cut in the center that instantly stripped out. Hence my frustration as I removed them out.

What he said. I wouldn't even bother putting them back in, mine doesn't have them and the undertray was held on just fine :).

I've also found the method of holding onto the outer ridge of those fasteners works really well, keeps it from spinning. I've never really stripped one out though, just have to be gentle and not try to force them.

^ I will try that next time. Doubt I will be putting them back in either. Oh, and I need to read my post before I press send, man was my original post riddled with errors...

those cheap plastic fasteners are used on all sorts of cars for body related pieces, there's nothing different about Mazda using them. I've seen them on plenty of Hondas, Subarus, and Fords for example.

http://www.fastenal.com/web/products...0162612&ucst=t
The two rear ears of the under-tray I use this type of retainer^
http://www.mactools.com/popup.aspx?s...UPT100-SET.jpg
Holds fine, they're reusuable and easy to deal with if removed with a tools like this^

And I'm not sure about that one you had in the front. Mine only ever had the two at the rear that went into holes on the crossmember.

They work just fine if you understand how to extract/install them properly. Try spraying a small dab of PB on them before working them out.



LAter

I take a little tiny flathead screwdriver (like the kind you use to repair glasses) and use it to lever the center bit out while unscrewing it with a regular phillips. Makes short work of those fasteners.

My biggest gripe about the undertray is the clips that the 10mm bolts thread into. When the bolts are even the slightest bit seized and you apply any amount of force to remove them, the nut on the fastener breaks from the fastener and starts free spinning. Then you have to get another 10mm wrench up inside the bumper to hold them in place.

I have found a very nice selection of similar type fasteners at Lowes. Very economical, about 50 cents a piece. Take one of yours with you to match sizes.

Great advice! ArmitageGVR4, I will be sure to take it easy when torquing the undertray back in and will be buying some anti-seize when I start putting everything back!

Just chuck those plastic fasteners in the trash, get some appropriately sized jack nuts, washers and bolts and be done with it.

Here's an example:

http://www.mcmaster.com/#jack-nuts/=5ms4x5

I got mine from a local ACE Hardware store in 6x1 metric. May have been 5x1, will have to check.

why don't you do what everyone does and leave them out?

some people are just too fucking anal... why not replace the undertray while you're at it so then everything is nice and new! be sure to roll a new car on top of it while you're at it.

you could also install some self crushing drywall anchors in it's place also, then you have a nice reusable mount and you can forget about the craptastic rivets if it's really that important.

Perhaps you should take a look at the URL I posted and actually read it before you get all pissy.

Those 'rivets' are also called jack nuts - they crush and are installed with a nut, a bolt and couple of wrenches.

Makes removing/installing the undertray a lot easier.

LOL :D Rough Day?

It's my car and I can do with it as I please. ;)

These are the bane of my existence. The bumper hinged on this when I tried to pull it off and chewed up the paint on my fender.

http://i37.photobucket.com/albums/e5...t/DSC_0145.jpg

Judging from the advice in this thread, I should just destroy them?

I think the two they were talking about were underneath the car on the splash pan/undertray, sort of underneath the engine area, not the 2 silver and 1 black one in your attached pic, nor the 2 at the top of the radiator opening.

I only ever had a problem with the bolts rusting. The plastic ones on the underside of the radiator opening were pretty easy.