Hi,
This hanger bolt and nut came stock in this location when I purchased my 88 GXL off the showroom floor. My question is why is it so long and why is the end slotted? A regular flanged bolt and nut would suffice. My only answer is that they had a large quantity of these bolts on hand from a different application and wanted to use them up. Any ideas would be appreciated.
I have another mystery for you, why does the battery box have a plastic window in it? What is its purpose?

Rear hanger bracket

 

Hard to guess what Mazdas intention was, but if I had to guess, it's like a stud that helps align the engine to the transmission on install before you slide the two together far enough for the dowel pins to engage. The slot is pretty bizarre. No idea on that

I've never had the battery box in any of my cars so uh.... no idea lol

 

+1 that bolt acts like a stud so when you go to mate up the trans its got something to locate on, but its only the one so you're not over constrained.
the slot lets you remove the bolt without having to pull the intake.

 

Great, it makes sense that starting the transmission alignment on a long bolt, it will constrain any positioning movement to only pivoting. Get the input shaft lined up with the pilot bearing would be very easy this way.
The slotted end starts to make sense when starting the bellhousing hole unto this bolt you need some way to protect the starting treads from getting chewed up from the bellhousing. So you add a smaller sized area at the end of the bolt to help get the hole aligned and take the initial contact.
The slot is a mystery still. It does make it easier to tighten or loosen this very long bolt. It gets pretty tedious using a ratchet on it. Probably saved a whole 2 minutes on the assembly line.

Anyone else have a reason?

 

In my haste to remove the engine I just threw the nuts and bolts into sandwich bags without labling where they go! I know better!

Here are five grade 10 bolts and lock washers, I have know idea where they go! The clutch plate takes 6, the transmission mount takes 4. Please help me find where these go.



They have those soft shoulders and no flange!
Two different lengths, The two longer ones have shanks.

 

those are for the pressure plate, if you look there are two different types of holes. no idea why, it just is

 

Thank you, it seems one bolt and washer took a walk.

I will have to search the other part bags for it.

 

As I attached the new pressure plate I noticed that two of the holes in the flywheel have threads that start about 1/4" from the top!

So, I figured the two longer bolts go into these holes.

I checked the depth of all the bolt holes and they were all the same!

Ok, when I attempted start the short bolts they would not reach the holes because of the free height of the pressure plate.

I managed to get one started by pressing the plate inwards but the opposite edge was canted away from the flywheel. I could not push the edge close enough to start another bolt.

But if I just slightly started one of the longer bolts into its hole, I was able to get the other longer bolt started in its hole!

After tightening these two bolts part way I was then able to start the other four shorter bolts.

Once they all were started it was easy to tighten them in a cross ward pattern. Then using a torque wrench I brought them all up to 20 ft/lbs.

It makes sense once you know what is what, do all clutch plates use a similar arrangement? Why not just use longer bolts all the way around, perhaps to keep fast mechanics from mounting the pressure plate slightly canted onto the flywheel?

 

Here is a part that goes under one of the clutch slave cylinder mounting bolts.



Does anyone know what it does? I have been running for years with the wire broken off!

I found it in the shop manual, E-11 condenser. It hooks up to the oil pressure gauge unit E-10.

This is the replacement piece, has the wire but the plastic connector has gone to dust along time past!

Need to spend some time cleaning that rust off.

 

If I remember correctly, it's a capacitor that's used to smooth out the response from the oil pressure sender so the needle on the gauge doesn't bounce around

Plastic connector is this guy: https://www.corsa-technic.com/item.p...ategory_id=199
You should be able to use the Yazaki P/N to cross shop your preferred vendor. Original color is natural nylon

 

To check electrolyte levels in the battery. At the time, factory battery bodies were that semi-opaque white plastic and had high/low level indications molded into them, which you could inspect through that window.

 

>>> It makes sense once you know what is what, do all clutch plates use a similar arrangement?
>>> Why not just use longer bolts all the way around, perhaps to keep fast mechanics from mounting the
>>> pressure plate slightly canted onto the flywheel?

Rather than those special bolts, S5's use dowel pins to center the PP. S5's also use the same length bolts, six in total, to secure the PP to the flywheel.

 

As pzr2 mentioned, it's a capacitor or otherwise known as a condenser. They both do the same thing. They only react to a varying voltage. They are a open circuit to a DC voltage. There should be two of them on your car. The one that you show that's bolted to the slave cylinder and the other one it bolted next to the igniter. Supposedly, one is for the oil pressure gauge and the other is for radio static suppression. Don't loose them because they are NLA from Mazda.

 

Great to know these things, is the mounting bracket of the condenser part of the electrical connection? I was considering priming and painting the metal to prevent further corrosion. If it needs to be metal to metal contact I will just put a coat of dielectric grease over it.

Thanks also for the link to get connectors!

Here is one ground wire I found the reason for, you know that wire that clips on the firewall and goes to a bolt on the top of the bellhousing!
It's to ground the AM antenna in the windshield, also those ground straps from the body to the mufflers, to stop radio static from the moving exhaust gases building up a static charge inside the mufflers! Nice to know!

 

They double as locators so the pressure plate can only go onto the flywheel one way. The shanked bolts only fit in two holes in the pressure plate and they only fit in two holes in the flywheel. You can't flip the pressure plate 180 degrees because there are three dowel pins.

 

It is a two terminal device. The mounting bracket serves as the ground. Just FYI, in case you need one, a similar condenser is still available for the FD and RX8, but the electrical connector may be different. Here is a link: https://www.atkinsrotary.com/93-11-R...A1-66-991.html

 

Everyone has been so helpful, can you please help with these two parts?


It appears to be some kind of cap that clips onto something, wonder where it belongs?
It is 10mm tall x 18mm wide.

The next pictures are of a connector either cut or broken off with 4" of black wire attached.





I found it loose around the top drivers side of the engine.

Could it be from the original condenser that was missing its wire?

I need to look at the wiring harness and see if it fits somewhere!

 

Photo 1 - cap for the CAS adjustment nut. No sure why Mazda used it. It has no useful purpose.
Photo 2 - ?

 

O2 sensor wire?

 

That connector gets used on both the O2 sensor (harness side) and knock sensor (also harness side) if you're turbo. But you said GXL so I'm assuming not.

 

Ran down to my engine and took this picture of the bolt!


This was another mystery bolt!
Now we know!

I'm guessing that the Mazda people did not want people messing with the timing unduly! So, make a bolt that has a cover attach over it!

 

O2

I will go look over the harness and see if it is missing!

Is it true that the O2 sensor signal is only used when in 5th gear? That the signal is used to adjust the A/F ratio?

 

Yeah, it was an anti-tamper device. Completely useless!

 

Not really useless... distributors needed to be adjustable because when you adjust or replace the points, or even as the points wear, the timing changes, so you have to be able to adjust timing as part of your regular tuneup procedure (every thousand miles or so).
With electronic ignition, the breaker plates still wear a little and you need to be able to adjust the timing.

With a crank angle sensor, that sucker is set and forget. Once it's set correctly, it should not ever need to be touched. So, it gets a litte bitty Elizabethan collar over the nut.

And, for what it's worth, TIL why FC front covers have that funny shaped stud! FB/SA covers had bolts, not studs...

 

no! it uses it from ~1500-3500 in every gear

correct!