I may have a 12A tranny on my stock 85 SE. The gears are short,ESPECIALLY 5TH GEAR. my rpm's rev up to high; they don't drag. When I hit 70mph on 5th gear, my rpm's are at about 4000 rpm. I know this is very high. My friend has a stock SE and his rpm's at this speed are about 2500 rpm. I was told by Mazdatrixx and other reputable rotary mechanics that I may have an earlier 12A tranny. Mazdatrixx checked out my car and said the differential is not modified, but stock. They said an SE tranny is hard to come by but can install a 2nd gen tranny. Is there any write ups about this and any good mechanics who can do this modification? I live in los Angeles, CA PLEASE I NEED YOUR HELP. THANKS

 

There should be a thread in the archives. Iirc, you take the FB tailshaft and install it on the FC tranny and you're good to go.

 

Im in Silverlake/Echo Park area.

 

..only turbo2 trannies and 3rd gen trannies differ from 1st gen trannies. also driving a 12a is different from driviing a 13b.

 

I'm quite sure the gear ratio's are different from say a na s4 tranny to a 85 12a tranny

 

Hey!! Wackyracer, what is your # so we can talk. Also I need more info on the tranny conversion . Also I need an a/c specialist here is Southern CA. Please help. Thanks

 

i may need a new tranny if i cant get the starter bolt hole fixed in my current tranny. i currently have an earlier tyle(79-80) tranny going on a 4 port 13b. i have a friend who has two 2nd gen trannies he has been trying to get me to buy for some time. if i get one and take the tail shaft off of my 12a tranny itll fit in my car(80')? i can still use my driveshaft? will i need a 2nd gen starter? what about slave cylinder? i have a brand new one on mine that hasnt seen fluid yet.

 

Wait, it's not supposed to be 3800 or 4000 rpm at 70 mph? I still get like 27 mpg on the highway. I always assumed my car ('84 GS) was bone stock. It only had 95k miles on it when I got it....

Kev

 

pm's ya

 

I think the SA tailshaft housing is different, and cannot be used on an FB/FC trans.
What year is your chassis? This comes into play as well, as the SA shifter is ~2" ahead of the FB shifter, which also ~2" ahead of the FC shifter. Putting an FC trans, into an SA chassis, will result in the shifter being ~4" too far back.
I believe the starter/ slave/ driveshaft (at the trans) will all interchange between SA/FB/FC(n/a).

 

the chasis is an 80', but the tranny tunnel has already been cut to fit a FB tranny by the previous owner. i can get ahold on an FB tail section if thats what i need.

 

If the tranny tunnel has already been cut, install an FB tranny and be done with it. Iirc, you can't mix and match the SA/FBs like you can the FB/FCs.

 

Wackyracer what is your # so we can talk about the conversion. Who in southern CA can do this conversion for me?

 

This mod is straight forward. As others have stated you remove the tail shaft housing from your existing trans and install on the fc one. Starters interchange as does the slave. You will also use your trans mount from your old trans. The switches for back up lights and for the 5th gear get used from your old trans.

One way to tell if you have a Se trans is that it will have 2 switches on it. One for the back up lights, the other for the 5th gear that sends a signal to the ecu for the o'2 sensor. It will also have a vent on the side of the trans.

Your friend that you say is around 2500 rpm when he is doing 70mph does not sound correct. It should be around the 3300-3500 range.

 

i would do so, but i dont have an FB tranny at my disposal. my neighbor has an SA as well, but had an FB parts car. he has the FB tranny but wont sale it. he wants to keep it as a spare for his SA. he doesnt want to cut the tunnel so i could probably trade him tail sections so i can have an FB tail section. i also have a friend who has two FC trannies im going to look at this weekend. if they are in good enough condition ill try to get the FB tail section so i can od the swap. FC trannies are way easier to find down here in deliverance country. i dont think i could find either too easily, but the FC would definately be easier.

 

Isn't it funny how you guys hijacked caddy83's thread?

 

on my tranny. at 25mph in 5th gear, its 50rpm, but its something to work with.

I have a 84 tranny, supposible/my car is so hyrbid....

 

why is it funny? thats not unusual

 

i think wacky pm'd you check your private messages!

 

It was a rethorical ? When do you plan on going back to the pick a parts?
See how i am now hi-jacking the thread.lol.

 

You should explain to your nieghbor that the SA/FB tailshaft housings are not interchangeable, therefore, he would have to cut the trans tunnel in order to use the FB trans.
The shifter tower is totally different between the SA and the FB/FC. Heck, on an SA, you can pull the shifter to fill the trans with oil, where you cannot on an FB/FC.

 

Thanks for all your help. Now I need someone out there who has a GSL-SE tranny for sale or nows how to do the 2nd gen tranny conversion to fit the 1st Gen SE. Anyone out there in Southern CA, please help. Thanks

 

I still need your help with converting the 2nd gen tranny to my 85 SE. Can anyone in southern CA do this conversion. OR do you have a good used SE tranny. Help

 

Are you sure your in 5th gear, thats sounds right for 4th gear? Maybe you do have some odd ball tranny after all.

In my 80 12a with stock drive train in 5th gear ~3000 RPM is 65 and 4000 RPM is 85 and 5000 RPM is 105. I used a calculator to figure this out because my speedo is a bit wonky sometimes and I keep a postit on the console to keep me honest.

Here's a calculator I've used in the past:

http://4wheeldrive.about.com/gi/dyna...om%2Fauto.html

Inputs:

3.909 (final drive ratio)
.825 (5th gear ratio)
22.68 (205/60 R 13 tires)
vehicle_mph (calculate the mph)
4000 (rpm to calulate from)

answer: 84 mph

 

I called you and left a message last week.