sbeers

So I'm gettin my 12a auto rebuilt soon as I'm going to convert it to manual can I just buy like a aftermarket aluminum flywheel for79 12a off mazdatrix ? Or do I need to find a stock one ? It can I use my auto one ? Also would I need a manual drive shaft ?

Thanks Shane

Cerberus7

Im going to be doing the same thing. I have the Manual Flywheel already, and the Pedals and Cylinders. I need to pick up a transmission still. Im unsure if we need a different Driveshaft or not, and also I have factory LSD

Good luck with your swap, would love to see some pictures of the car!

sbeers

Ahhh nice man your pritty much set .so wait do I just need a 79 year flywheel and it will work? Right now I have nothing. I'm just makeing a big list and prep for everything. I need. Once income tax comes. Ill be starting the whole process ill create a build thread

I'm still undecided if I should rebuild it my self yet ... As. I have no experience .

And ya. I'm thinking ill need a manual drive shaft . But I'm not sure yet lol I have a friend up did a swap ill ask soon to make sure .

sbeers

And ahhh if I hve extra cash left over and. If possible. Ill do a rear end swap but that's the last step .

Thanks Shane

Cerberus7

Yea, its not a costly swap at all. Tranny can be found for around $50-$200 Max. Driveline $50 at the most, the pedals and other stuff is relatively cheap. You can find a gasket set for around $100 if your doing a rebuild yourself, thats if your apex seals are still going to be good.

Cerberus7

Buy the carb rebuilt kit too, might as well go all out so its like new. Carb kit is about $40 from what ive seen.

sbeers

Ya I found trannys for 100 and ya I'm buying a kit that has the gaslit kit and Alex seals . Also I need find a cheap engine lift thing ... But ya I plan on getting the car kit to as my carb has multiple leaks I'm also gonna strip it down like no emmisions .... Just it's gonna be a big big learning process...

sbeers

Ill have like 4g for everything so it should be pritty nice also going to just get a small street port hopefully this all we start gettin done in.about. A month

Jeff20B

iTrader: (13)

You asked about flywheels. If you can find an 81-82 flywheel, it will bolt right on and correctly offset the rotors. It weighs 23 pounds which is a huge improvement over the stock 79-80 flywheels at 30 pounds.

Cerberus7

Ok so the flywheel must be change in the swap, good to know. Is anyone sure on the drive line?

Jeff20B

iTrader: (13)

If you already have the auto rear counterweight, you could get an aluminum flywheel like you mentioned earlier. Or a light steel flywheel. I prefer the light steels myself.

As for the driveshaft, I think all 83 and older auto and manual are the same. Only the 84-85 were different for auto vs manual because they had an overdrive that made the autos longer. You should be fine. But you should get a second opinion as I've only ever done an auto to manual swap in a 76 Cosmo and I could reuse its driveshaft.

You will also need to jumper a connector in the center console so it will start. It's the parking and neutral lock-out. You will also need a manual starter which I'm sure you already know.

ArmyOfOne

iTrader: (12)

I agree with Jeff on the light steel ones. ACT streetlight is what I am running. 13lbs is not as terrible as people say it it. I drive my bridge ported combination port on the street with one and a sintered iron 6 puck.

cfamilyfix

iTrader: (15)

...and you will need pedals lol...(since no one mentioned it yet)

FunK73

iTrader: (6)

When I swapped mine I used the factory balance weight from the flex/drive plate in combination with a RB light steel flywheel. You of course need a drive shaft and clutch set up to match the transmission as well. You also need the hydraulic system for the clutch, which will bolt right in, including the hard and soft clutch lines. The hardest part is installing the clutch/brake pedal assembly. Also make sure you get all the boots for the shifter. Heres a list:

-Stock Counterweight from Flex/Drive Plate
-Aftermarket Flywheel for use with counterweight, you can use a stock flywheel for the same year/series of motor as yours is now as well
-Clutch disc, pressure plate, throwout bearing
-Clutch master, slave cylinder, and lines associated
-Dot3 Brake Fluid For Clutch System
-Clutch and Brake Pedal Assembly
-Transmission with matching drive shaft (I would stay within the same year/series if you can to make sure your differental flange matches the drive shaft)
-Transmission Mount needs to be fabricated for a 84-85 car
-Shifter and all associated boots (3 parts I think?)
-Inerior Trim for 5 speed car

sbeers

So i decided to swap my 85 12a in but im going to use a 79 sa tranny what fly wheel and counter wight would i need?

sbeers

I would just use my 85 transmision but idk how to fab

MIKE-P-28

iTrader: (1)

You use a SA trans better start chopping the floor up. The shifter is farther forward. Use the 85 trans. Doesn't make any difference what trans you use the flywheel has to match the motor it's going in to. 79-80 is the same. 81-82 same. 83-85. Has to be a 12a flywheel of course for 84 and 85

MIKE-P-28

iTrader: (1)

Oh driveshafts are the same. Just starting in 83 the rear flange at the pinion is different. Same shaft. 84-85 are difference cause of the OD trans it's longer. Trans mount the same. Don't have to fab anything about a 2 -3 hour swap

sbeers

So if im correct id just need a flange ? And. It be done? And lol prob more then two hours for me as this will be. A first for me... And i have the flywheel and everything as im just pulling it all from my 85 base....

hoang5659

iTrader: (14)

i want to attempt to do a flywheel install but i dont know how the orientation or how the counter weight and flywheel go fit together. can someone post a diagram or a picture of how they go together? i bought a used flywheel and a counter weight from someone on the forum but i dont know what i need to get it installed.

Siraniko

iTrader: (13)

I hope you were referring to aftermarket flywheel and rear counterweight. LMK if you need more pix.

KansasCityREPU

iTrader: (9)

You can't use the 79 flywheel with a 85 12A. The flywheel must be matched to the engine because of the rotating mass. For a 85 12A, you must use a 84/85 flywheel or use the 84/85 auto counter weight with a light weight flywheel like RB sells.

This is one question that has been asked many times. It also should be mentioned that the clutch plate size is different between years ranges. 84/85 uses a 225mm clutch plate and 79 uses 215mm.

This will help.

Flywheels

Flywheel and Clutch Explanations

hoang5659

iTrader: (14)

thats exactly what i needed! thank you. where do you get the bolts that hold the counter weight to the flywheel? i purchased the aluminium flywheel hardware kit (nuts and bolts). i hope that will have everything i need. thanks.

Siraniko

iTrader: (13)

racing beat sells the kit. mazdatrix sells racing beat stuff