Miata Turbo Forum - Boost cars, acquire cats. - Turbo Smurfette

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If the R&P are still rigidly attached to their respective shafts/carriers, perhaps, by complete coincidence, its two sheared-but-still-in-the-boot CV joints at the diff?

Broken shit inside the differential itself, stripped splines, ect...

Updated pics. The axles where fine, stubs weren't spinning with driveshaft. The axles were removed easily and splines look alright.

Is it friction material? Can OSGiken be rebuilt?

From OSGiken website

Due to the precision manufacturing, high-grade materials, and unique design, a break-in period nor rebuild is required for OS Giken LSD’s. OS LSD is purposefully over-engineered to offer the best performing, most durable clutch-type LSD available.

The problem is inside, which doesn’t surprise me. I can’t say I have seen broken ring and pinion gears in 1.8 Miata diffs as long as I have been on this forum.

Yep, saw a broken carrier once tho.

Has anyone ever heard of pinion splines shearing?

Not yet, is that the problem?

Not in miatas but it happens in the diesel truck world sometimes

What's the rebuild schedule supposed to be on one of these? I think the axle splines would shear before the pinion failed. If I were a betting man I'd check your belleville preload washers for any obvious fractures or plastic deformation and if you open it up probably good to inspect spider gears as well. Maybe you got really really really lucky and someone goofed on the heat treatment leading to both sides failing simultaneously.

Quote:

Originally Posted by Spaceman Spiff (Post 1498456)

I have no clue where to take it for rebuild or if there's a kit. I have no clue how to test this.

Check out this video I think he does a pretty good job of explaining.

I think (but have absolutely never torn one of these apart before) that want to check those conical "spring" washers on the outside to see of they are indeed still spring-y enough to preload & are whole, and the inside spider gears for any visible cracking or pitting.

The one thing you do need however is the torque pattern/specs to put it all back together but I imagine OS Giken provides this.

I saw that video and it is definitely informative. If it is the diff, I'm still surprised since I haven't read a case of this diff failing other than in a 1300hp skyline

Found a video on YouTube, my axles where definitely locked in but this is what it does and what it sounds like.

So after seeing Aidan's twisted axle boot, James pointed out to me that mine had looked the same. If the CV popped apart (which it did when trying to remove it), would that leave the other wheel stranded since there isn't enough resistance for the LSD to function properly?

I'll admit, at this point I'm stumped and may have overlooked the overlooked this detail. I didn't see the axles moving, but perhaps in the cloak of night, the stub was spinning in place, with the boot dragging behind, slipping at the steel clamp, twisting, but not tearing.

Is it worth the effort to reinstall and just try a new set of axles? Or should I have a shop inspect the lash and all that crap while it's out.

You don't have to reinstall. Just stick the axles in the end and sping the pinion while it's out of the car.

depends how much effort you want to put in.

imho... something should be visibly wrong if its not moving at all.

Or check your axles. Mine was very obviously broken.

@Shibby do you remember if we checked if the axle splines where spinning when we rotated the pinion?

One axle is for sure popped apart, I thought it was because I was yanking on it for removal. But James pointed out the boot was twisted up before we even dropped the diff. I thought that the accordion part was just kinked from lifting the car. I didn't even think the cv was busted.

I may have seen the shaft stationary, but didn't confirm the driver side stub. I knew the passenger side stub and axle didn't move. But I feel like when manually checking the ends, I could pop it back in and it felt engaged. Advanced Auto said I can return it for direct replacement, should I cut the boot open first? I don't know what I'm looking for.

We didn't check that. I just trusted you when you said you didn't see them move when the car was still on the ground.

Yea, shaft didn't move, I couldn't see the stub on the driver side, but I could see the entire passenger side stationary and driveshaft spinning.

This was all on the side of the road waiting for a tow at night. Ultimately my car battery died anyway so we couldn't replicate anything when we dropped the diff.

Hopefully they'll replace the axle still, no questions asked, when it's disassembled.

Now I need to get a work bench and vise :p

That must be a big sigh of relief knowing you just need a new axle now.

Yea. It's a free exchange since it's a Car Quest /Advance Auto axle. But this lasted 2 years. I'll swap the new ones in and just order a set of DSS sometime this winter for backup. Looks like I can wait on the Getrag diff conversion and ride this one out a little while longer.

I honestly want to credit Aidan for posting up his twisted boot photo of his axle carnage.

Let's hope the replacement does indeed fix, it seems likely.

In other news, I'm stock piling parts again.
https://cimg2.ibsrv.net/gimg/www.mia...b61f591d4a.jpg

Fuck yes!

The picture of the outer spline is truly impressive.

What was the FIRST comment I made in L33T chat when Nadia posted his axle? I sez in the chat I sez: PAYAM SHOULD CHECK HIS AXLE :D

PS: judging by the gnarliness of that axle, I'm guessing ~450 :)

Lol this happened on pump. I guess I was in panic search mode I didn't bother scrolling up in chat. I just dropped my axles off at Advance there waiting on one more to come in later today. I'll start picking away at reinstalling the diff throughout the week. I feel as though perhaps that housing was already cracked and then through time it just fatigued or wore out the splines

Quote:

Originally Posted by 18psi (Post 1498632)

PS: judging by the gnarliness of that axle, I'm guessing ~450 :)

I'll be sure to have a fresh set of axles in the car when we fly you over.

That's a BMW 6speed.

Quote:

Originally Posted by sixshooter (Post 1498646)

That's a BMW 6speed.

Playing the long game.

Quote:

Originally Posted by psyber_0ptix (Post 1498640)

I guess I was in panic search mode I didn't bother scrolling up in chat.

Never scroll up!

:laugh:
never scroll up
never surrender
to ALLOF IT..........and BEYOND

Driving at 70mph went wub wub wub. I indexed the driveshaft on the flange 90° and it went away.

Back in action! Waiting to find a junko head. Then maybe in fall, just refresh the head that's in the car and try again next season

Why are you looking for a junko head? Just to swap heads and keep the car running till you can do the valves on the current one?

I want to try something

Not much going on with my car because I've been busy with other projects....

Building a work bench:
https://cimg9.ibsrv.net/gimg/www.mia...353244ac33.jpg

Building a wall to convert the space under my front porch as a storage space:
https://cimg1.ibsrv.net/gimg/www.mia...15802f3f8d.jpg

Making a new computer desk out of Caro Black Wlanut:

https://cimg0.ibsrv.net/gimg/www.mia...51d3b641f9.jpg https://cimg1.ibsrv.net/gimg/www.mia...112e9e04f3.jpg https://cimg4.ibsrv.net/gimg/www.mia...822017bb06.jpg https://cimg3.ibsrv.net/gimg/www.mia...b425f3bdc0.jpg

https://cimg2.ibsrv.net/gimg/www.mia...9360d50c9e.jpg https://cimg5.ibsrv.net/gimg/www.mia...de17c15d79.jpg

Helping a friend change the clutch in his weird looking Miata. What a pain in the ass

https://cimg6.ibsrv.net/gimg/www.mia...9ad4af2bbf.jpg

Helping Shibby rewire his car:
https://cimg7.ibsrv.net/gimg/www.mia...2927d30d37.jpg
https://cimg8.ibsrv.net/gimg/www.mia...af1634ec66.jpg

Smoking a turkey for Friendsgiving:
https://cimg2.ibsrv.net/gimg/www.mia...ad4a4ce342.jpg
https://cimg0.ibsrv.net/gimg/www.mia...8a9965f35c.jpg

And finally.....had a thing made. I'll rip the head off, and try to test the leakdown past the rings (removing valvetrain from the equation). This will help determine if I need to pull the engine for a rebuild, or just service the head. Remember, I'm currently having 38% leakdown through what we believe is the exhaust valve.
https://cimg9.ibsrv.net/gimg/www.mia...8741061e8b.jpg

bonus point, you can bolt that plate to the head and check leaks there too.

Quote:

Originally Posted by shlammed (Post 1509320)

bonus point, you can bolt that plate to the head and check leaks there too.

This is true, but I know the current head needs help, we can hear it out the turbo. It's easier for me to remove just the head than the whole engine so this is in an effort to save some labor. Car is kept outside, in a driveway, under all weather conditions. If a head comes off, it's easy enough to schlep it to a shop

Quote:

Originally Posted by psyber_0ptix (Post 1509340)

And the leakdown adapter plate will keep crap out of the engine while you leave the head off :party:

Cool bench, those help a lot.

https://cimg6.ibsrv.net/gimg/www.mia...d6a966a94d.jpg

OK, finished making my new computer desk. I guess I gotta focus on car now and take the head off and test leakdown of the rings soon.

https://cimg1.ibsrv.net/gimg/www.mia...f599e321a1.jpg
I don't like this. Working outside in the cold sucks.

https://cimg2.ibsrv.net/gimg/www.mia...d69a99410c.jpg
Will cleanup pistons but preliminary inspections shows no signs of detonation. Head looked okish too but I'll let the machine shop take a look at the valve guides and seals. Or just run the Super head and let someone else deal with this refresh.

https://cimg0.ibsrv.net/gimg/www.mia...13d0560cb9.jpg
Need to make a couple spacers then will check leakdown past rings

Super head doo eeeettt

Quote:

Originally Posted by matrussell122 (Post 1514107)

Super head doo eeeettt

this

That's a big maybe right now. There is someone interested in the Uberhead. It would have been awesome for science, but I feel like at this point, the transmission is the biggest concern. I do have that ZF 6 speed sitting in my driveway ready to go..........

uberhead.
then ubermanifold
Then ubertrans
then uber7163

If you want we can test the uber head on my uber manifold and uber turbo. Just for science then you can have it back haha

Quote:

Originally Posted by matrussell122 (Post 1514446)

If you want we can test the uber head on my uber manifold and uber turbo. Just for science then you can have it back haha

plz 7163.

Quote:

Originally Posted by psyber_0ptix (Post 1514441)

Is your 6 speed still in one piece? I guess it is a ticking time bomb at your power level.

Quote:

Originally Posted by shlammed (Post 1514456)

plz 7163.

If he sends me a head ill order a EFR 7163 TS tonight haha

Quote:

Originally Posted by andyfloyd (Post 1514458)

Is your 6 speed still in one piece? I guess it is a ticking time bomb at your power level.

I'm still on my first 6speed, 4 years running. Snapped my first axle a couple months ago and that was just two years old.

As Vlad keeps tinkering with megasquirt my car makes powr and falls apart that little bit more.

We were outside doing dent removal stuff to my girlfriends car as I kept looking back at the miata. The mirrors just looked so worn and though trying this with some spare marine epoxy laying around...what's the worst that could happen? They already looked pretty beat. 45 minutes of work spruced them up.

Very interesting. Came out super nice!

Hello all, time for an update.

It's winter again which mean I'm in crisis mode trying to figure out if I have motivation to continue this project. As many folks already know, I struggle from time to time with parting out and starting over from scratch. I've talked to Shibby about it for over a year, and he finally pulled the gun and decided to move on. Buy His Stuff Here. I made the mistake of tabulating a for sale list and was staggered how much I have in this Miata and saddened about the amount required to cage it and buy a Kmiata trans kit to make it as reliable as can be. I just don't think I can cross that hurdle. Even though I already have the Getrag transmission on standby. Then it's axles...then its.....

I've described it recently like being in a bad relationship. You've settled, you're comfortable, don't have the will power to change, but secretly look at other cars/projects and think of what could be. I question if I actually enjoy working on this car, it has no nuance. I love working on my friends' cars and find the quality of work is generally higher than what I commit to working on my own. It comes and goes in waves; the urge to part out because it makes financial sense. But sentimental thoughts reel it back in, and it's a pretty tumultuous cycle. I have to admit, I could use the liquidated assets for other things right now, house stuff, accelerate loan payments, even pick up a shell and start over with a more modest build that would be more huckable around the track. Tax return this year is pretty garbage so that doesn't help....that would have been my ticket for the BMW trans kit. I feel like I've crumbled at the finish line before me. It's just a question of part out now - rip the bandaid off, part out later after enjoying it for one last summer/MATG, or try to sell it whole and take a massive loss but be done cold turkey.

As it sits the car is not assembled. Head is coming back from the shop soon. Lot's of changes to the setup that I may or may not actually get to run depending on how things go. This will be the third iteration of the build and there's still a make-or-break test I need to do. Leakdown past the rings. If it sucks, then I honestly wonder if that'll be the tipping point. If everything is fine, then I might just mindlessly continue reassembly and squeeze one more season and a couple track days in before parting ways. If there is any catastrophic failure, I don't think I'll rebuild. If the stock 6 speed shreds after 18psi tickles the megasquirt, then I don't think I'll rebuild.

New for 2019:
Refreshed head with cams. I suspect leaky valves, so I had it sent off for a checkup. Also sporting the Supermiata reroute. I also happened to stumble on another set of tomei cams and impulsively purchased them which I fully regret. 2019 year of regrets.

Fluidampr - just something to try. No reason really, the Supermiata damper had been fine but again, I've been impulsive because boredom.

Twin scroll manifold
Top mount ramhorn. I'm keeping the EFR6758, but going to try out the 0.8 A/R T4 turbine housing. It's probably a bad idea, but this bad idea has been brewing for nearly two years; I'd even spoken to Abe about it before he committed more time to family. It's just been an ear worm after talking to matrussell122, Geoff at Full-Race, and a couple other folks. Just want to try something different because I'm bored and need stimulation. If it sucks, at least we will have data, and I can always go back to the trusty old single scroll. Ridge Fabrication was able to jig my Artech manifold so it keeps the same downpipe position and compressor housing orientation. It's an easy comparison because downpipe and intercooler are untouched. Very cost effective. Dual port IWG and 4 port EBC. I still envy Aidan's potentiometer controlled boost set points.

Aero?!
I have a splitter, designed by afm that I've been meaning to mount for some time. I also have a 9 Lives Wing because I'm cheap on the aero. Or I could sell it all and part the car out. I don't know. I already picked up a paint matched trunk for $100 so I can cut it up for the uprights.

ABS Knuckles?!
still need to replace all the bearings and hubs. I'd also like the transfer the SADFab upper spherical bushings but will likely have to torch the sleeves out of the current knuckles. I want to pirate the ABS sensors for possible traction control. Or just get rid of it.

If you made it this far, thanks for listening to my complaints. Just in a pretty bad funk.

Your reward
https://cimg7.ibsrv.net/gimg/www.mia...b044f09fe9.jpg

Getting messy
https://cimg8.ibsrv.net/gimg/www.mia...310ab31bc8.jpg

TLDR;
Financial priorities are changing. I'm not sure if this project does it for me anymore. I kinda want to start from scratch. I don't know if I should reassemble once more, enjoy and part out...or just start gutting it while I'm ahead. If I catch some inspiration to try one last time we can look forward to a cammed VVT head with a twin scroll setup for science. I have too much pride to start a go-fund-me for trans kit, but would gladly take stickers and poscats instead.

I hate to say it, but it really sounds like you're done with the project. If you don't have the love for the car or a strong desire to see it finished, a part out would probably make the most sense.

One thing I don't understand, though, is the desire to start over with another shell. I don't get that. If you don't want to chase huge power anymore and want something usable on track, why not sell your big power parts and put together the track build you're talking about? I can't understand parting this out just to start another Miata project over from scratch.

An s2000 or ND, otoh...

I read it. Allofit. And basically feel the same way/agree. Though if you're really this close, I'd throw it together and at least enjoy for one last time. Nothing worse than spending money only to get to hold the part and nothing more. Mechanical empathy will go a LONG way and you'd be surprised at how much that 6sp will hold with it