86gxl_fc

Hi, Is there a place where I can find the thread/pitch/length of all nuts/bolts on the FD?
Mainly need those to bolt clutch/flywheel/trans/starter up and a few for the fd front end as well.

Thanks guys.

Spalato

iTrader: (33)

The FC guys have a good thread about the bolts and thread pitch for the FC. It would also be helpful to have something similar for the FD.

So most hex heads/nut sizes on the FD are 8, 10, 12, 14, 17, 19, and 21mm

08mm hex head/nut = M5 x ???
10mm hex head/nut = M6 x 1.0
12mm hex head/nut = M8 x 1.25
14mm hex head/nut = M10 x ???
17mm hex head/nut = M12 x ???
19mm hex head/nut = M14 x ???
21mm hex head/nut = ???

So these number above are just assumptions, I'm going from the standard sizes used for metric bolts and nuts.

If someone could fill in the above list it would be very useful!

My FD is not near me now so I cant go into my garage and measure anything. I actually wanna buy a set of nice thread chasers to fix nuts and bolts when I get back on working on my FD and knowing the exact thread pitch would be very helpful.

j9fd3s

iTrader: (3)

check out page 1-I2, its about 9 pages in. they explain the parts numbering system for some of the standard pars, of which nuts and bolts are mostly a part of.

http://foxed.ca/rx7manual/manuals/pa...000A-4600A.pdf

the gotcha is that the number isn't the actual size, its relative. so it doesn't SAY its a 6mm bolt that is 20mm long, but if you know that the bolt that goes somewhere is a 6mm x20mm (which will be by default a 1.0 thread), and the other spot uses a 30mm bolt, you will then know that the part number goes from 9979-12-820 to 9979-12-840.

the bolt style refers to if it has a washer, or not, or a lock washer.

quickest example is a stationary gear bolt, 9080-12-820 is the one for the rear, the front, which is longer is a 9080-12-825. then the intake manifold bolt, is the same length, but does not have the captive lockwasher, is 9979-60-825, and of course we know these are all 8x1.25 bolts.

a 6mmx1.0 bolt, which i just grabbed at random is, 9978-00-612.

there are nuts/bolts that are specific to the FD and catalogued like any other part, so those wouldn't have the size in the part number.

j9fd3s

iTrader: (3)

Mazda uses JIS fasteners, so a 6mm x 1.0 bolt has a 10mm head, and the 8mm x1.25 bolt has a 12mm head, etc. there are exceptions, but they are exceptions

Spalato

iTrader: (33)

Yes, those two I listed. How about the other sizes? Do you happen to know the bolt size and thread pitch for the 14, 17, 19 and 21 hex heads?

Spalato

iTrader: (33)

So after searching some JIS docs, I believe the 14 head is M10 x 1.25, and the 17 head is M12 x 1.25

j9fd3s

iTrader: (3)

most of the time the 14mm head is 10mmx1.25, but the exhaust is all 10x1.5, and the tension bolts are 10x1.0 with a 17mm head. the 12mm is kind of the same, for instance the wheel studs are 12x1.5...

Spalato

iTrader: (33)

So according to the JIS standards the FD should have the following common hex head, bolt and thread pitch sizes:

08mm hex head/nut = M5 x 0.8
10mm hex head/nut = M6 x 1.0
12mm hex head/nut = M8 x 1.25
14mm hex head/nut = M10 x 1.25
17mm hex head/nut = M12 x 1.25
19mm hex head/nut = M14 x 1.5

The only one I can't find is the
21mm hex head/nut = ???

And obviously there are exceptions.

The only exception that I know of is the brake line flare nut which is 10mm hex and M10 x 1.0

Please correct any of this if its wrong

Spalato

iTrader: (33)

Ok thats good to know! Thanks.

So other than the wheel studs at M12 x 1.5, are any other bolts that are M12 also 1.5 or is that wheel stud specific and the other M12 bolts are 1.25?

Sgtblue

iTrader: (16)

And just a reminder that these would be Grade 8.

86gxl_fc

I know I am a bit late in saying this but thanks alot guys.

j9fd3s

iTrader: (3)

off the top, the M12x1.5 are the wheels, including the steering wheel, the A/C p/s bracket, and the cat.

so i use the steering wheel nuts to hold my engine to the engine stand, and i've seen lugnuts on the cat before...

the chassis may have some M12x1.25, as those get torqued tighter

billyboy

I don't think you can make that assumption unfortunately. You'll find similar numbers on a variety of fasteners from the various OEMs, which don't correspond with any grade standard if it was true - if anything, a production line thing.

j9fd3s

iTrader: (3)

or the guy making the bolt is named 9

Sgtblue

iTrader: (16)

It's an OEM pressure plate bolt. And it's a relatively unique marking that not all bolts of that size have and used where the application would dictate a hardened bolt. So pretty fair assumption IMO.

billyboy

7 is common on a fair few Japanese vehicles, not a known grade afaik. It does give you a standard torque value - and I suspect a quick visual confirmation the tool you're picking up at your station won't take the heads off once you pull the trigger.