Need help - FB 12A into an RX2
07-12-13, 10:12 AM
#1
Need help - FB 12A into an RX2
Embarrasing but...
I tried to install a 12A from a 84-85 RX7 into my RX2 yesterday. It seemed the tabs on the front of the RX2 manual transmission would not match-up with the tabs on the rear housing of the 84-85 12A.
What's the secret? How do I bolt an 84-85 12A onto an RX2 transmission?
I tried to install a 12A from a 84-85 RX7 into my RX2 yesterday. It seemed the tabs on the front of the RX2 manual transmission would not match-up with the tabs on the rear housing of the 84-85 12A.
What's the secret? How do I bolt an 84-85 12A onto an RX2 transmission?
07-12-13, 10:19 AM
#2
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Hmmm, are you certain that you have a 12a? 84-84 RX7's where all GSL-SE's that only came with the larger 13b. The stock Rx2 manual trans won't fit, since it's a 12a setup.
07-12-13, 12:02 PM
#4
Respecognize!
all GSLSEs were GSLSEs that had 13bs. But they had the GSL, GS and base models as well with 12a through 1985
07-12-13, 02:58 PM
#6
The RX2 transmission has a top mount starter. I converted the RX7 12A from beehive to front-mount oil cooler, and this opened-up the space for the starter. It looks like the starter will not be a problem.
The upper tabs for the "transmission to block bolts" look like a problem.
The upper tabs for the "transmission to block bolts" look like a problem.
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07-13-13, 03:05 AM
#8
74-85 12As won't bolt up to original Rx-2 4 speed box! Twin dizzy 12As had totally different bolt hole configuration. You'll need a rotary gearbox from 74 onwards. If you really want a 4 speed you could use an rx-4 or repu or some base sa22s had them too.
07-13-13, 10:43 AM
#9
The easiest dimension to check is the upper right and lower right transmission bolt holes (facing the rear of the motor.) If they are 9.5" apart, it is early (pre-1974.) If they are 10.5" it is 1974+
Does anyone have a 1974+ RX2,3,4 transmission they want to sell?
07-13-13, 11:47 AM
#10
74-80 are going to be your best options as far as shifter location and requiring less hacking of you trans tunnel, as all 5 speeds are longer than the stock 4 speed is. I have 79-80 rx7 5 speeds in both of my Rx-2s and a Rx-3 SP 5 speed in my 73 Rx-3. You're going to have to get your driveshaft shortened and balanced too. Please don't listen to any of the clowns on here that insist on you throwing away your 2 piece drive shaft. It's there for a reason so use it! Hit up your junk yards for a box and make sure to grab the bell housing bolts and the starter too.
Good luck grasshopper
Good luck grasshopper
07-13-13, 06:23 PM
#13
74-80 are going to be your best options as far as shifter location and requiring less hacking of you trans tunnel, as all 5 speeds are longer than the stock 4 speed is. I have 79-80 rx7 5 speeds in both of my Rx-2s and a Rx-3 SP 5 speed in my 73 Rx-3. You're going to have to get your driveshaft shortened and balanced too. Please don't listen to any of the clowns on here that insist on you throwing away your 2 piece drive shaft. It's there for a reason so use it! Hit up your junk yards for a box and make sure to grab the bell housing bolts and the starter too.
Good luck grasshopper
Good luck grasshopper
RX-2 13-B TII streetported with semi-pport T72 turbo ONE PIECE DRIVESHAFT never had a problem 130 mph grasshopper
07-13-13, 07:09 PM
#14
I believe late 73 model had a side starter that mated to a early engine, I had one years ago. I never seen one since.
If you have a later 12a, I would install a 79-80 5 speed and yes you can install it with the original 2 piece drive-shaft, No need to shorten it or re-balance it, just some minor mods that will take about a hour.
FYI: RX2-Mazda-Fan and Gravity Fed, 74-91 engines will bolt on to any 74-91 transmissions 12a or 13b as long as the flywheel clears the bell housing.
If you have a later 12a, I would install a 79-80 5 speed and yes you can install it with the original 2 piece drive-shaft, No need to shorten it or re-balance it, just some minor mods that will take about a hour.
FYI: RX2-Mazda-Fan and Gravity Fed, 74-91 engines will bolt on to any 74-91 transmissions 12a or 13b as long as the flywheel clears the bell housing.
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