LocostUSA.com

Yikes! That is nasty. A little JB Weld and a few zip ties should fix it.

Aren't certain RX7 housings the same? Wonder if those might be less expensive?

*edited for links*

I thought the internals and the housing were identical to the 1.8 Miatas and the only difference was the actual main housing and the pinion? Can someone confirm if these will work since I could be making this up?

http://cgi.ebay.com/ebaymotors/88-RX7-C ... 20bbb803cf

http://cgi.ebay.com/ebaymotors/Mazda-Rx ... 483b5ac77c

_________________
-Andrew
Build Log
Youtube

I think you're right Alex. Check out solomiata.com/drivetrain they have a pretty good comparo. I may have to hit the junk yard on my lunch break and see what the inventory of rx'rs looks like.
Thanks for the tip!

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In God We Trust... All Others, Bring Data.

Miata based, custom chassis build in progress. First Drive!!! http://locostusa.com/forums/viewtopic.php?f=35&t=2269&start=375

Well, there was a glint of hope and progress today. I called the local junk yard and they're more than happy to sell me a diff housing for relatively cheap. I think the actual price depends on who rings you out and what kind of mood they're in, but I'm confident I can land either a 2nd gen NA RX-7 or 94+ Miata diff housing for under a Benjamin. - That was the first piece of good news.

The second piece came after I broke open the pumpkin and got a good look at the diff internals. - I was surprised by what I saw.

When I first bought my donor I was pretty confident it had a Torsen diff, but I did the famous test everyone brags about which is:
Raise the rear end up, hold the drive shaft steady (i.e. put it in gear with the engine off) and turn one wheel forward. If the other tire also spins forward, you have an LSD. If the other tire spins in the opposite direction you've got an open diff. Right!? Wrong.
My tire spun the opposite direction and I was confused as to why the options list didn't match up with reality.

In a 'youtube or it didn't happen' world, I knew I wouldn't be believed, so here is the proof. Guts exposed to the world so you can see what's going on.

http://www.youtube.com/watch?v=3Pw2fKt_0As

I've browsed the 'spotters guides' everyone references on miata.net, solomiata, miatagarage etc. and none of them really tell you how to identify the 1.8 variety Torsen LSD from the outside. They come close, but read them in detail and you'll find it's just not there. With the famous 'spinning wheel' method now debunked, I can confidently say, the only good way to determine if you have an LSD on your hands is to put eyes on the internals. - I've heard rumors you can call Mazda USA with the VIN number and ask them, but somehow I question just how helpful they would really be. With a million or so Miata's zoom zooming around out there I doubt they have a customer service department just dedicated to answering questions for inquisitive owners of 15 year old track rats.
Anyway. I hope my two cents helps some poor soul out there...

The internals look AMAZING for approaching 200k miles. I would have expected a lot more wear and play. I think I'll replace the rear housing and go drive another 200k.

_________________
In God We Trust... All Others, Bring Data.

Miata based, custom chassis build in progress. First Drive!!! http://locostusa.com/forums/viewtopic.php?f=35&t=2269&start=375

With any luck I'll be back on the road this weekend. I pulled a rear housing from a 2nd gen RX-7 yesterday. I can say without supposition that 2nd gen RX-7 and 7" miata rear housings are compatible. I've read some different reports as to whether the stub shaft seals are the same size or not but they measured out the same and seem to be interchangeable.
I cleaned it up and luckily had some ultra black RTV on hand.

The only thing different appears to be the shape of the cooling fins and placement of the drain plug. Unfortunately it's farther back on the RX unit. It made wrestling the beast into it's home even tougher than before. I have literally a couple of millimeters to spare when navigating the obstacle course that is the rear bin.

I'll be stiffening up the mounts and raising it a small amount to help combat the 'prone to cracking' feature of the previous set-up.

I had to do a good bit of disassembly including removing the gas tank so all that is on my list for tonight. - on the road again just in time for the snow. . .

_________________
In God We Trust... All Others, Bring Data.

Miata based, custom chassis build in progress. First Drive!!! http://locostusa.com/forums/viewtopic.php?f=35&t=2269&start=375

[quote="rust_bucket" - on the road again just in time for the snow. . . [/quote]


Snow? It's only Halloween, you won't even have a chance of snow for at least 4 more months.

_________________
mobilito ergo sum
I drive therefore I am

I can explain it to you,
but I can't understand it for you.

You must be an Aussie! As a kid I trick-or-treated in the snow more than once. Utah may have the best snow on earth, but it doesn't come cheap.

_________________
In God We Trust... All Others, Bring Data.

Miata based, custom chassis build in progress. First Drive!!! http://locostusa.com/forums/viewtopic.php?f=35&t=2269&start=375

No Aussie, but definitely below the Mason-Dixon line.

Truly? Trick or Treating in the snow?

That just doesn't seem possible.

_________________
mobilito ergo sum
I drive therefore I am

I can explain it to you,
but I can't understand it for you.

it's Alive!!!

OK so it doesn't have quite the same effect when it's already been through the maiden voyage posts... But come on! It IS Halloween. I couldn't resist.

I finally got it all put back together and on the road tonight - just in time to catch a midnight rainstorm. I may have doddled too long there is snow in the forecast tomorrow.

Everything seems to be working fine. No drips, squeals or clanging so I count that as a win. I'm sure I'll still find a handful of sunny afternoons to take it before the burly ice monsters set up camp. - and hey I think I may have to do some 'research' so I'll be able to speak truthfully when people ask me "how does it go in the snow?"
The answer of course is: "oh it's a great snow-car, perfect for a 'donut' run.

_________________
In God We Trust... All Others, Bring Data.

Miata based, custom chassis build in progress. First Drive!!! http://locostusa.com/forums/viewtopic.php?f=35&t=2269&start=375

Its nice to hear the housing rumors are true and everything fits together.

Hopefully the warm weather holds out for you (or Tire Rack has a good deal on Miata sized snow tires ).

_________________
-Andrew
Build Log
Youtube

Rusty,

Your crazy still driving it. I put my car away almost a month ago. The ground just gets to cold and the tires just slip to much to be fun.

BUT WHAT THIS MEANS IS its time for winter projects. What do you have planed for the car?

I've got a list for my car, don't know how much I'll get done since we are going to be moving to Lindon.

JR

_________________
Attention TURBO LOVERS, Great book -----> How to turbocharge and Tune your Engine
Sold: GT30/71R My00 S2k
My Car: Custom Build Lotus Super 7

Ah yes, the 'to do' list.
In no particular order here is THE LIST:

-Add a small knee pad for the driver on the trans tunnel
-Add a heat shield for the Master Cylinders. - No problems yet, but I want to add as a precaution, if nothing else to help preserve the rubber seals on the reservoir lids.
-Sew up a tonneau cover for the rear bin
-Replace the 'this'll do to get me through' upper radiator hose with a more permanent solution like a custom bent Aluminum jobbie.
-Install a heater of some variety
-Fab some wind wings
-Fab a bikini top
-Change the fluids
- And the real pipe dream is to re-make the hood and scuttle. I've never been completely thrilled with the profile I ended up with. It's a tad boxy. After looking at some real Caterham's at SEMA this year I realized that the cross section is really more fluid and round in the middle of the hood. The scuttle to windshield line is a 'frowny face' bow as opposed to a straight line like I have. Add that dislike to the need to come up with a cover for the hole in the hood around the engine, and the unpleasant fact that my scuttle is as HEAVY AS SIN I am itchin to rebuild.

The proposed solution would be to remove the existing hood and scuttle and use the car itself as the starting point for a buck. I would cover the engine and sensitive bits with poly and then build up a buck to the profile. It would be easy to get the shape I want because it would be right on the actual car. I could just shape and re-shape until I got it right.
I'd then pull a mold and shoot a part. I have some ideas of how to make both a hood and scuttle from the same mold.

We'll see. It's not the part making I'm afraid of, it's all the time required to make a good mold… There's part of me that knows myself well enough I'm afraid to start for fear that I'll drag my feet all Winter. Then Spring will come around and I'll have a car that can't be driven because it has a fragile buck on it that still needs to be finished…

We'll see what happens. I've had so much fun driving the thing as-is it's really hard to want to tear into it. I guess now that the weather has turned that distraction is reduced.

I'm kicking myself that we never got the 3 Utah 7's together! We'll have to do it in the Spring for sure!

_________________
In God We Trust... All Others, Bring Data.

Miata based, custom chassis build in progress. First Drive!!! http://locostusa.com/forums/viewtopic.php?f=35&t=2269&start=375

Looking great! I just bought your copy of Tanner's book on Half.com. I'll be lucky if mine ever looks half this good!

_________________
442 Miata based build
http://www.locostusa.com/forums/viewtopic.php?f=35&t=10327

Good on ya flightrisk! Fire away with questions. As you can see from reading back through my build log, there are A LOT of folks on here with ample experience and very good advice. I look forward to seeing your build!

_________________
In God We Trust... All Others, Bring Data.

Miata based, custom chassis build in progress. First Drive!!! http://locostusa.com/forums/viewtopic.php?f=35&t=2269&start=375

Well, I'm committed (to the project.) If not, I should be committed (to an institution) because I've started the new composite hood. I'm taking pictures along the way and will update when there's a little more to show, but the basic approach is this:
Remove the existing hood and scuttle
Stack engine bay and scuttle area with cardboard and other 'egg crate' type structure to build up a rough shape.
Fill out the surface with expandable foam
Smooth to rough shape
Finish with bondo (the master)
Apply gel coat or other separating coat such as latex to makes sure the mold resin and bondo don't get too cozy…)
Lay-up mold on master (glass and polyester resin)
Extract the mold - modify for flanges and scuttle to hood separation features (more on this later)
Lay-up the epoxy/carbon hood in the mold (wet lay-up, vacuum bag cure).
-Trim to fit and install. (Oh yeah, form new windshield frame and cut glass)

Obviously there are a lot more details than that and I'll share along the way.
- So far, so fun! I've got the first rough shape done and the first refill and smooth coat is curing.

_________________
In God We Trust... All Others, Bring Data.

Miata based, custom chassis build in progress. First Drive!!! http://locostusa.com/forums/viewtopic.php?f=35&t=2269&start=375

Good luck rusty. I'm sure it will turn out great!

JR

_________________
Attention TURBO LOVERS, Great book -----> How to turbocharge and Tune your Engine
Sold: GT30/71R My00 S2k
My Car: Custom Build Lotus Super 7