Broke My Diff In Half... CHEAPEST and EASIEST Miata Diff Upgrade You Can Do (RX-7 Parts)

Hopefully I don't blow any apex seals after installing this thing
www.thecarpass...
MUSIC:
DJ Quads - It Just Makes Me Happy ( • Video )
Otis McDonald - Not For Nothing ( • Otis McDonald - Not Fo... )

[@cmoore74]

Hey Greg... the diff carrier you’re using is from a S4 (86-88) Rx7. The S5 (89-91) carriers are 2lbs heavier. The S5 has thicker webbing across the "beam" .475 vs .320 for the S4. The S5 also has been triangulated in the beam area as well as having the lower web of the beam merge with the output shaft saddle. All in all the S5 is a beefier unit.

[@TheCarPassionChannel]

Good to know!

[@benmarsh9236]

Hi cmoore74, does it matter if the diff is from N/A or turbo, are they all interchangeable?

[@benmarsh9236]

I'm just talking about the carrier, not the whole diff.

[@cmoore74]

Ben Marsh the turbo diff carrier will not work as the case itself is larger and the bolt holes don’t line up to the diff casing. I have two extra carriers if you’re interested. We could discuss over PM.

[@benmarsh9236]

@@cmoore74 Yeah I'm interested. How do we PM on here?

[@4399daniel]

Miata Dad back at it again with a fresh upload. It’ll be worth being late to the office for this 😎

[@jwsalome]

Been waiting for a decent video. Had a FC diff sitting under my VG swap wondering if I could use it.

[@craig7111]

I’ll be doing diff seals soon so this helps as a refresher 👍🏽👍🏽

[@joro8604]

U r a Wizard

[@Silverboy005]

Man if I could I would buy that diff from you when you sell it but im way too far

[@kzam374]

dad!

[@vseunos9261]

Good job, thanks for the tip broke several on my v8 miata.

[@mythicanomaly3079]

idiot

[@dil6969]

@@mythicanomaly3079 very rude

[@vseunos9261]

Really was that necessary

[@vseunos9261]

I can get 10 miata diffs for the price of 1 strong diff so I didn't care but its nice to know there is this possibility

[@callen3282]

@@vseunos9261 sounds like some v8 roadsters envy.

[@miguelbueno774]

It's just like uncle Ben says with great power comes great diff destruction

[@MrOnemanop]

Uncle Ben was just a cheap Ricer......

[@alantran6901]

Weld plates onto the stock diff. It's cheap and just as effective. Bolt on plates are never as strong or rigid.

[@sam_scott_85]

This. The bolt-on plates are a joke.

[@rockyrocket78]

When holes 🕳 are drilled it made it even weaker. I welded mine no problems

[@devinolburgettoo8314]

AGT also have welded plates and it’s solid

[@OniMX5]

What kind of plates did you use? I haven’t welded before, is it aluminum?

[@delpedrob6994]

​@@OniMX5probably some 6 or 8mm plate welded with a Tig

[@mentallystablekanyewest1504]

The one dislike is the diff carrier

[@miralemnermina142]

At least you didn't blow up the transmission again, can't wait for +400hp pulls

[@akirony]

14:22 i watch for that joyous face when things actually go right. And RIP that front lip, may the asphalt have mercy on its soul

[@DeathOrGloryRacingBC]

Borrows parts from stronger car then mocks it in description. That's a kick in the rocker panels.

[@natemorris535]

Project D 😂😂😂

[@Zadnak1]

Do you think the K-Miata differential arm reinforcement plates made a difference in prolonging the life of the diff before it snapped?

[@bakedandsteaked]

Surely it does

[@thelonewanderer420]

It held it together so he could get her home, that’s worth something

[@Zadnak1]

@@thelonewanderer420 good point

[@Jamesfurtado128]

@@thelonewanderer420 to be fair thats worth what ever it costs. Saved on a flat bed and could probably drive lightly for a little while too

[@mathiasmang848]

I don't think it would brake if you weld plates like those in there

[@miatasman9594]

So glad you posted this after I got mine Haha I'm sure the price on rx7 housings is gonna skyrocket actually watched your diff bushing video last week rock on Greg!!!

[@deanedwards5030]

Do the RX7 housing use the same axle seals as the MX5, or are they RX7 seals?

[@miatasman9594]

They are the same

[@miatasman9594]

Bushings are not though

[@couvboiz6712]

Ken E I can’t even find any on eBay 😂

[@couvboiz6712]

Ken E do you know if you have to set backlash and preload?

[@ryanlocher4177]

For a second i thought you were gonna clean your wheels😂

[@TheCarPassionChannel]

P S Y C H E

[@chromabalisong]

I just found a Miata for 600 bucks with just a broken differential with no other issue and low mileage, if he sells it to me il hopefully will be able to repair it thanks to your super helpful videos

[@drmoss_ca]

I get face ache driving my NA - the stupid wide grin that lasts for as long as the trip.

[@TheJohnb35711]

Got me thinking an FC RX7 would be a great new project on the car passion channel...

[@Nasonix2]

yes but i care about seeing him do more work on the main miata especially after the new drivetrain swap lol

[@qers]

I want to see him swap in a BP engine.

[@TheJohnb35711]

@@Nasonix2 more work? This thing is a masterpiece.

[@Zadnak1]

Greg, do you not have an 18v or 20v half inch impact wrench? If not, do you want one?

[@zGenjin]

Milwaukee M18 Fuel will be all you’ll ever need

[@khawajadotd]

I imagine he could get one if he wanted. I'd bet grrg's strategy is to use hand tools to keep everything approachable for new mechanics who don't have "fancy tools" An impact isn't all that fancy nowadays, but noobs don't always know that

[@natemorris535]

Gen RIP M18 Fuel is my favorite tool in my box

[@Loopyengineeringco]

The crack in the broken carrier runs right through the bolt hole there. If the hole was drilled, that's definitely what weakened it!

[@RobOrtiz22]

are you gonna do a build cost video?

[@TheCarPassionChannel]

Very very very soon, I'm thinking within the next 3 videos or so. Already in the works

[@nicolas6820]

Lets put some numbers to see if we get close, i bet greg spent like 20k $

[@erasmus_locke]

Who seriously thought that piece of aluminum was going to strengthen the diff? I like Kmiata but that one piece was a guaranteed failure.

[@callen3282]

Would love to see an rx7 clutch pack swap to go along with the diff carrier. I have a na8 now and I never swapped the guts on my 1.6. So I have this thing laying around with nothing to do with. I devour every video you post buddy. Much love from the bluegrass state.

[@19mati67]

Most likely, the brace hole screwed up that carrier(the hole weakened it). You should have welded the brace.

[@GeneralPoison]

This. And what's up with the square cut out opposite side of the weakening notches? This would'nt have broken if these two things were'nt done to the housing....

[@derakbell8143]

Its July where are the mustang destroying videos? No drag vis for almost 3 years seems like

[@Culilin]

What's up with that front lip?

[@bobm9509]

You are by far the least controversial channel I am constantly unsubscribed from. Thought you'd like to know.

[@TheCarPassionChannel]

KZbin is crazy sometimes 🤷🏼‍♂️

[@bobm9509]

While I briefly have your attention, love the channel. Especially as your work environment is similar to mine. Could you please work on a rust belt car once in a while so I can enjoy someone else dealing with rusted parts? Thanks.

[@braydoncoate9583]

Bro how do you only have 90k subs still ive been here since around 70k and youre videos are epic

[@TheCarPassionChannel]

I appreciate you fam ♥️

[@MrMeierRecordz]

Is the spring in the diff seal important? Noticed that I forgot to put them back in, and it's all assembled now 😅

[@marinusgouw]

lipseals definitely need that spring in there.

[@Airsoftdude3252]

Yes it won't seal without it

[@realweston]

“I need to look good for my fan.” @15:48 🤣 singular, only one fan? Lol

[@Nasonix2]

fam lol

[@mgamma5001]

Hey G do you know if all FC RX7 diffs will work... Turbo any stronger than the the NA FC. BTW nice work and love the pointers on the seals as mine are about to get replaced.

[@TheCarPassionChannel]

Turbo FC diff is way stronger but can't be used with the PPF without modifications

[@rnelson1415]

I love that exhaust note, but I like seeing you back on youtube even more!

[@uh5291]

I was wondering if your exhaust touched the kmiata PPF delete kit. I have that kit that Im gonna install and on a dry fit, my resonator interferes. Thanks.

[@bandwagon240]

Typically, I hit the bushings with my purse.

[@pedroortiz9858]

Whats the diference betwen the turbo2 and non turbo It will still fit?

[@TheCarPassionChannel]

No - T2 uses an 8" ring gear and has a bigger housing. 1.8 Miatas and n/a FC's both use 7" ring gears.

[@copous1613]

Nice. I was going to do this but I just went with a turbo II diff and axels. Still have the rx7 na diff if anyone wants it

[@TheCarPassionChannel]

T2 is an even better option.

[@copous1613]

@@TheCarPassionChannel yea just have to make some custom bracing and get a new drive shaft made other than that it's also a bolt on.

[@Sertao2013]

I have a 2003 miata and my diff broke in the place you show in the video . What year rx7 housing should I get so I can use the diff I have . Just to be clear I can use the diff I have and it will fit a rx7 housing right ? I noticed you said fc rx7 at 15:07 . what year does the fc rx7 carrier come out of ?

[@dil6969]

I feel bad for you having to deal with that bastard driveway. Time for a concrete-ectomy.

[@jwsalome]

Saw this video when it came out. Today, I ordered the PPF delete kit for my VG30 swap. Thanks for the constant inspiration Greg. 🤟🤟🤟

[@TheCarPassionChannel]

😳 Which VG are you using??

[@daylindrake768]

Do you have a pinion seal replacement video

[@thefriendlyitalian]

If I use the N/A FC clutch differential. Am I able to reuse my axles?

[@Manuqtix.Manuqtix]

Why is the 1.6 diff weaker? Is it the crown wheel and pinion?

[@codllc]

The S4 N/A RX7 can have the clutch type diff. The S5 came with a viscous or open diff.

[@Procharged32]

There's no give in those newer type bushings wouldn't help to not breaking.

[@Nebbia_affaraccimiei]

14:53 isn't that uniball joint on the sway bar link a bit off-axis?

[@Nasonix2]

I was thinking the same lol like it's supposed to be something like 90degree in relation to the sway bar or something like that. Sometimes u have to swap over longer bolts and use some washers to get it propped right

[@alexchulzhanov]

The car is jacked up

[@Nebbia_affaraccimiei]

Alex Chulzhanov it isn’t?

[@alexchulzhanov]

Nebbia affaraccimiei hmm, my mistake. As long as the sway bar is parallel it doesn’t really matter. Not like there’s enough suspension travel for it to bind.

[@mauriciofiladelfo3027]

Hey there, I've been watching your video for long time and a big fan. I have a few questions wondering you could answer cause I'm using cd009 transmission. 1st were you making over 450 to 500hp when you installed the rx7 diff if so do you think reinforcing the diff bracket would help? 2nd i saw you upgraded the rx7 diff to a Cadillac diff and it solved a lot of issues you were having. Do you think it was necessary cause you didn't explain if the rx7 diff was a temporally fix or if it broke as well? My opinion are staying with rx7, or ford 8.8, cadilic o 350z? The car will be making 500hp and wanted tour input. Thank you.

[@mauriciofiladelfo3027]

I found the information that i was looking for. Will be reinforcing the diff for now.

[@gremotorsports]

I have NA miata open diff internals welded in my fc rn. Go team Mazda lol

[@VinnyVentures]

I got the Torsen 3.9 I think. Super pumped.

[@dougiequick1]

WHY is the Miata diff so wimpy compared to RX7? Well HOW do you think Mazda kept the weight down to 2300llbs? If one needs everything up super stout? Ultra braced and reinforced? LOL Car won't be a feather anymore ....I would think some bracing could be welded onto the stock diff? Either that or just don't get so crazy obtaining more and more power

[@TheCarPassionChannel]

The RX7 housing is probably 2-3lbs heavier and is significantly stronger 🙂 it's all about finding the balance between power and strength

[@jmpcrx]

I make that 'will it break' face too when I mess with things.. But yeah, this is such a great channel, thanks for spending so much time making all your vids.. Will be going through each one as I'm now starting my own nb turbo build, wanna get it right and learn from your mistakes!

[@AGRFABRICATIONS]

Greg you need clutch type LSD in your life with that 3.6 gearing....BTW why the hell you spend 450dollars on that thing ? I could send you one from Europe for like 200 dolars, or other guys from Europe, so you could spend more money elsewhere :D

[@TheCarPassionChannel]

I wish I knew!! Everyone in the U.S. pays $400-$450 to have them shipped here :(

[@dustinleebladesmith9135]

I'll buy your old diff when you get your Getrag setup!

[@kentuckysleepyhollowband1611]

Hay man so I have a 1.6 diff that I have narrowed down and boxed and welded how much power do you thank it will hold with stock gears car is super small and only weighs 1350 lb. Any knowledge helps :)

[@TheCarPassionChannel]

The biggest limiter in the 1.6 diff is the gear set unfortunately. They're good for about 200-250wtq, but being in a lighter car will definitely help

[@venzant40]

Anyone know if welding it is viable?

[@benlastname8270]

14:08 CRANK UP YOUR F-ING SPEAKERS!!!!

[@DeffectiveMirrors]

Did the front lip break at the end of the video?

[@beatricethemiata8565]

Thought u used the kmiata diff brace thing..🧐🧐🧐

[@Nebbia_affaraccimiei]

Beatrice the Miata that’s just to keep the 2 pieces together

[@bakamotorworks505]

Ryobi send this man some power tools!

[@TheBreakfastClb]

On the bright side diffs are easier than transmissions lol

[@Alexwaltman850]

Did you use RX7 or Miata axle seals? Gonna be installing mine with a euro 3.63 Torsen rear end next weekend

[@TheCarPassionChannel]

Miata

[@aidengonzalez8073]

Another front lip bites the dust :(

[@grim9515]

Oh shit you're back!

[@testacorsa150]

13:16 The sudden unexpected beefed up zoom gave me a good laugh. Another great entertaining video. Keep it up Boiiii

[@cbkenison]

No weight comparison????

[@NLSNMedia]

ay dog what happened to your front splitter

[@michael_christian9461]

Gahh i need a job so i can save up for my own miata

[@Thee_Sinner]

6:20 Ooo look, a penny!

[@robertwilson369]

Does the fact you lost the power frame support have anything to do with the diff carrier snapping?

[@TheCarPassionChannel]

Very likely, although once I went to the RX7 housing I didn't have any problem.

[@dimefury510]

that bolt hole weakened that housing, that plate didnt help at all and probably caused your housing failure

[@TheAdatto]

Duhhh he says it's designed to break there.

[@brandonpetrisky2058]

Double like for the end bloopers.... Ha ha

[@michaelbrown6157]

Does it only work with 1.8 torsen? Or would it work with 1.6 or 1.8 vlsd?

[@TheCarPassionChannel]

The housing will only fit onto 1.8 differentials. Any type.

[@chazworm3]

I hate to be a fuddy duddy but what is the weight difference of the differentials. How much HP are you getting. Sounds very nice.

[@TheCarPassionChannel]

The weight difference is maybe 1-2lbs only, they are both aluminum, one is just a little thicker. Currently the car is making 420whp/345wtq

[@jarrodwest5733]

Super nice of your diff to give your transmission a rest for a change :)

[@HenzPowell]

Now watch the prices climb....

[@Balancedviewable]

The stock assembly s not weak. you are way overloading it

[@TheCarPassionChannel]

Overloading it, as in making power 😊 Everything in the stock Miata powertrain is weak as glass inching the motor

[@GustavoGonzalez-uj7it]

Yo wtf happen to your lip

[@Zadnak1]

2 videos in a week?!? Keep up the awesome work! PS - Buy an NC!

[@38tech]

Never....na/nb for life....

[@MRTuning704]

A good tip on removing the axle seals and rear main seal is to drill a hole and then screw in it self tapper and then you can just pull the self tapping screw by the head with pliers

[@Nasonix2]

or yank it off with a pry bar haha

[@Amy-i5p5g]

Very helpful

[@blatantlyjohn6234]

RIP front splitter

[@carlosc6021]

OMG DAT LIP BRUH

[@connorbridle3189]

Curious why you’ve gone from 3.9 to 3.6? Wouldn’t that hurt the acceleration and street cred?

[@Nasonix2]

lowers highway cruising RPM, as well as makes it easier to reach 60mph in a zero to 60. Longer gears. A bit less acceleration though, like you said. although Definitely, definitely no less street cred tho

[@TheCarPassionChannel]

(I'm actually going to 3.42) Longer gears will increase traction in 1st, 2nd, and 3rd gear. Acceleration in X gear is lower, but you can also hold that gear longer (to a higher mph) which essentially cancels out that difference. When I went from 4.3 to 3.9 in my 275whp setup, it made the car faster in every way, especially at the strip. Also, longer gears are typically beneficial for boosted cars as you are shifting less often (so you're not falling out of boost) and, on my car specifically or anything with a fast spooling turbo, those long shifts don't hurt you because the car still makes a ton of torque even down to 3500RPM. In an n/a car it's typically beneficial to go shorter, because it makes it easier to stay in the high RPM where the power is at.

[@davidbonner2674]

What cage is in it?

[@DBatty]

FOR SALE: K Miata diff brace 😂👍🏻 Question.. 1.8 half shafts. I heard the MSM kind are thicker. Does anyone know if the splines into the diff are the same between normal 1.8 and MSM. Cheers

[@This0is0pointless]

Diff case, the carrier is what the ring gear bolts to no?

[@TheCarPassionChannel]

A lot of people call this the "carrier" because it "carries" the whole diff in relation to the subframe, but you know how the car world is man, everyone has their own name for everything lol

[@egeayvala1799]

fck end links :D

[@ericgarrison5097]

They built these diffs to serve the 120-140hp these Miatas came with,and they meant it. I've read mixed reactions to the rx7 diff. Some wrote they were great to supposedly like 500hp,others claim 300hp or more and it'll explode. I'm thinking if anyone is looking for more strength on a budget,the rx7 is the way to go. Me personally,I'd do either the heavy 8.8 irs or the lighter getrag. Both have plus's and minuses. 8.8 it's,is heavy but are everywhere pretty cheap. Buku parts and ring sizes are available. The getrag,it's much lighter than the 8.8,but no where near the aftermarket support and ring gears.

[@WKZworks]

Will an NA FC pumpkin bolt into the Miata in its entirety? I'd much rather have a Clutch type diff. Hell, I actually have a Turbo FC diff lying around. I may put that in there if it's similar enough.

[@Shakshuka69]

Somebody outta make/sell a truss for the diff carrier on our cars. Works great on Jeep axle tubes stopping them from getting banana'd by 40" tires and locked diffs.

[@henryliu8518]

Whats different between the FC NA and turbo diff carrier and why only NA version fits?

[@wayneclement7201]

Surprised you've not got an electric impact gun or ratchet Greg, would save you a lot of time, speeds things up a lot!

[@joshua_lee732]

He's used one in previous videos.

[@wayneclement7201]

Been watching his videos for ages now, that's the only reason I'm suprised!

[@juansierra387]

Hey Greg I found 90 RX7 diff. Can I keep the ring pinion on the FC for my 1.8?

[@TheCarPassionChannel]

If you change the ring and pinion it's a pretty in-depth process. I do believe they will fit since they both use 7" rings

[@juansierra387]

@@TheCarPassionChannel Sweet. Just double checking regardless still picking it up.

[@Dillyspec]

Was this for a 1.6 or 1.8 rear diff 3rd member?

[@TheCarPassionChannel]

1.8 Only

[@mikeb9569]

This just happened to my stock 2013 NC. It allowed my axle to separate as well. Luckily, the NCs mounting "ears" are on a separate mounting plate bolted to the diff.

[@owlytv]

Hi just wondering where you got the ppf delete kit from? Has it held up well? Lots more vibration noise?

[@christianzinn7636]

After seeing this I bought one from ebay for my build as extra insurance, but true to what you said with builds. Things didn't go as planned. The first one, the guy sent me the wrong part. He sent the front nose, not the rear case. He already sold the case, but was kind enough to let me return it and gave full refund. I turned around and successfully bought another case from someone else, cheaper...winning!

[@elwindewitte]

Talking about the PPF, does that actually make a difference to either the regidity or the performance?

[@BogdanBershadsky]

Thanks for your video! Will this mod fit to Mazda mx 5 NB SE 1.8?