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Question About A Part On An Old 75-7? Cosmo 5Spd. Tranny.

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Old 03-31-10, 09:56 PM
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Question About A Part On An Old 75-7? Cosmo 5Spd. Tranny.

I am swaping my RX4 4speed for a 5speed tranny from an old Cosmo. The Cosmo trans that I have does not have the shifter assembly so I am using the one from the 4spd. Everything bolts until you try shifting to 5th gear and reverse. There are 2 pins bolted on the right side of the bottom shift housing that prevented me from shifting 5th and reverse when using the shifter assembly from my old 4spd. tranny. Seems the ball on the shifter are hitting these 2 pins preventing shift to 5th and reverse.





When those 2 pins are removed I can shift to 5th and reverse using the old shifter from the 4 spd. Does anyone know what the functions of these 2 pins are?? I was going to cut the pins, but before doing so I would like to get anyones opinion or knowledge if its OK to do so.

Old 04-01-10, 12:50 AM
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i could be wrong since i've never had a 4 spd but it's possible the shifter for the 4 spd is different than the 5 spd shifter.
Old 04-01-10, 01:30 AM
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If they are not connected to anything cut those suckers.
Old 04-01-10, 01:55 AM
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The 4 speed shifter is slightly different than the 5 speed one it is actually in the shape of the pivot and the guide, I ran into the same problem when i changed a SA Rx7 tranny into an Rx4, you need to use a 79-80 Rx7 shifter, cosmo, 76-78 Rx3 or 76-78 Rx4, you have to make sure it is from a 5-speed (except the 79-80 Rx7 one they are all the same). If you slightly loosen the stay bolts from the shifter mount it will shift into 5th gear but that is not really safe because when it is the other gears the bolts are too loose. You do not want to cut those pins though they are there to ensure that the shifter is in the right position and doesn't put pressure on the cluster, without them you might as well be constantly resting your hand on the shifter which will cause excessive wear on the syncros which are fragile to begin with.
Old 04-01-10, 03:14 AM
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I had some luck once when I made a spacer out of I think 1/8" aluminum. Try this first because it's removable/reversable. Don't cut the pins.
Old 04-01-10, 12:04 PM
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Thanks all for the inputs. Just my luck the Pick n Pull had a 79 RX7 2 weeks ago now its gone. I'll try the aluminum spacer. Does anyone have a shifter mentioned above for sale by any chance ??
Old 04-13-10, 12:09 AM
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please verify

I found what supposed to be a 79-80 RX7 shifter, but its not working on my Cosmo trans. I installed the 79-80 shifter everything shifts from 1st to 4th perfectly , but I am still not able to shift to 5th and reverse due to the pins on the side.

Can you guys verify that what I bought is actually a 79-80 shifter. The one without the **** is the RX7 and the one with a **** is the RX4.



I was thinking the notch on the mid ball on the 79-80 RX7 would be opposite the RX4. The one I got has the notch on the same side. The bottom ball on the RX7 also has a shorter arm compared to the RX4.



The lever shift housings below are from the Cosmo(bottom) and RX4(top) are different. Notice the difference where the notch on the shifter ball would go into are opposite.



I am thinking I might not even have a 79-80 shifter. I did however use the Cosmo shift lever housing and I did put the RX4 lever the opposite way to fit the notch on the shifter ball. It did shift in all gears. Again this is with the shifter mounted the opposite way.
Old 04-13-10, 12:59 AM
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[/B]

I am thinking I might not even have a 79-80 shifter. I did however use the Cosmo shift lever housing and I did put the RX4 lever the opposite way to fit the notch on the shifter ball. It did shift in all gears. Again this is with the shifter mounted the opposite way.
Correction:

On the picture the Cosmo lever housing is the top and Rx4 housing is the botttom.
Old 04-13-10, 01:08 AM
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just replace the shifter housing along with the corresponding shifter. I will check my junk pile this weekend.
Old 04-13-10, 01:29 AM
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Bossing Melski, I'm going to try the matching shifter to the Cosmo lever housing. I've been using the RX4 lever housing on both shifters. Let me know if you find what shifter would correspond to the Cosmo shifter housing. I guess a RX? shifter with the guide or notch on the front side of the pivotin ball.
Old 04-13-10, 03:19 PM
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Originally Posted by WackyRicer
just replace the shifter housing along with the corresponding shifter. I will check my junk pile this weekend.
And we have a winner, use the rx7 shifter with the housing from the SA tranny no problems,

as always wacky knows best I am sure that he has done this a few times before.
Old 04-13-10, 11:11 PM
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thanks bro LOL
Old 04-14-10, 04:16 PM
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Originally Posted by WackyRicer
thanks bro LOL
see you at ss this year?? for good words i only charge one coke LOL
Old 04-14-10, 07:41 PM
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I will give you soemthing good in a cup LOLLL
Old 04-17-10, 01:45 PM
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b series

Well I'll try to match the 79-80 Rx7 shifter to a housing if I find one. I just want to make sure what I have though is really a 79-80 shifter. I was also looking at some older Mazda B series pickups which might also work, but not %100 sure. Below is a tailend picture from a 91 B2200 from Realms of Kyrasis. Looks like there are also 2 pins on the side.

Angelfire won't link any pictures so cut and paste.

http://www.angelfire.com/darkside/de...ailHousing.jpg
Old 04-20-10, 08:23 AM
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OMG you havent finished this tranny project?
Old 04-20-10, 08:44 PM
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Mel, I am actually working on the rest of the car to get it up and running again. Just waiting to find the right match for the tranny. Just haven't had any luck. I might be going to the JY this weekend hopefully to find a shifter and matching housing that will work.
Old 04-26-10, 11:35 PM
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I have several junk trannies you can have. just drive down and get it
Old 04-28-10, 11:25 AM
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Originally Posted by WackyRicer
I have several junk trannies you can have. just drive down and get it
you have more than trannies laying around. huh? haha
Old 05-02-10, 06:04 PM
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Originally Posted by migz808
I was also looking at some older Mazda B series pickups which might also work, but not %100 sure. Below is a tailend picture from a 91 B2200 from Realms of Kyrasis. Looks like there are also 2 pins on the side.

Angelfire won't link any pictures so cut and paste.

http://www.angelfire.com/darkside/de...ailHousing.jpg
GOOD GOD MAN!!!! I didn't think that site existed anymore I haven't updated that page in 7 years and that angelfire site was the first iteration of what is now Mazdatruckin.com!

Here is the most recent version of that page, it's only 2 years out of date, lol:
Mazda Transmission 5th Gear Swap

We truck owners often swap Miata and RX-7 transmissions by putting the truck bell housing, tail housing and shifter fingers on the doner transmission and then bolt it in. For those of us who do rotary swaps putting the truck tail housing onto the RX-7 transmission is a quick way to reduce the amount of fabrication needed.
Old 05-03-10, 11:36 PM
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I don't know if this will help, but here is a picture of the shifter from my 5 speed cosmo transmission that will be going into my rx4:


Old 05-04-10, 07:49 PM
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Thanks all for all the help!! Finally got a shifter assembly from a 90 B2000 to work. I took the 2 removable pins also from the B2000 trans and shaved a bit off the front pin for the shift lever to slide into. Saved my original pins just in case I ever find a true match for the Cosmo trans.

Originally Posted by WackyRicer
I have several junk trannies you can have. just drive down and get it
Mel, I'll pick up all your junk when I get o LA .

Originally Posted by Kyrasis6
GOOD GOD MAN!!!! I didn't think that site existed anymore I haven't updated that page in 7 years and that angelfire site was the first iteration of what is now Mazdatruckin.com!

Here is the most recent version of that page, it's only 2 years out of date, lol:
Mazda Transmission 5th Gear Swap

We truck owners often swap Miata and RX-7 transmissions by putting the truck bell housing, tail housing and shifter fingers on the doner transmission and then bolt it in. For those of us who do rotary swaps putting the truck tail housing onto the RX-7 transmission is a quick way to reduce the amount of fabrication needed.
Your site was helpful. Now to add the new site on my fave links.

Originally Posted by fromundr
I don't know if this will help, but here is a picture of the shifter from my 5 speed cosmo transmission that will be going into my rx4:




Thanks for the picture. I think my RX4 shifter looks the same as yours.




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