argatoga

I'm finally making progress on my belated Midget swap, the problem is that neither of the 5 speeds I have are comfortably short enough as far as the shifter position goes. I have two gearboxes one from the JDM 12A and the other from an '86 NA. Any suggestions for shortening either? Right now the older one is shorter by ~2in. I have heard of swapping in a B2000 tail shaft, but it doesn't look compatible.

blwfly

iTrader: (4)

i slipped the tranny in marked center in shifter location



i srewed up on the alignment pin and got it stuck i had to drill from the other side to knock it out.
here is a pic of the shifter the black line represents center of the repu shifter hole.


i cut the shifter rod and tube 6 1/4" smaller and duplicate where the alignment pin goes..


everything cut and welded


aliment pin in and housing shimmed for smooth shifting

Bugeye RX

That's frigg'n awesome, you got skill!

1973rx3

I second that!

blwfly

iTrader: (4)

lol thanks i simply started out like the guy above.. asked questions

i forgot to mention what ever amount u cut the tube down the rod get the same which made it really easey

rotarydude

iTrader: (2)

is that a NA FC tranny or a T2 FC tranny you did that to?

blwfly

iTrader: (4)

its a t2 tranny but im sure the other's cant be that different..

bwaits

iTrader: (12)

That is how I have always done it. Works like a charm.


-billy

rxtasy3

iTrader: (2)

did that to an 83 tranny to fit a 75 808 back in 93.

jgrewe

iTrader: (1)

Looks like it puts it right where the B2000 tail does.

argatoga

Does the B2000 tail move it that far back? I thought it gave only 1/4 of an inch?

argatoga

It doesn't look like the B2000 tail fits at all. Could you go into more detail?

kustomizingkid

iTrader: (2)

Very nice work!

Nothing that couldn't be accomplished with some fairly simple tools too!

argatoga

Does anyone know anything about the tailshaft housing then? If not I'm going to proceeded and use the 12a's tranny.

jgrewe

iTrader: (1)

I set up a 12A in a Midget a few years back and used a B2000 tail housing. It put the shifter within about an inch of the stock Midget location. The B2000 tail won't fit the T2 tranny though(I don't think, never had them on a bench together, just know they are way different trannys).

blwfly

iTrader: (4)

jgrewe will the b2000 fit a n/a 2gen tranny??

jgrewe

iTrader: (1)

Yes. They fit all the NA trannys that have come in RX7's. AKAIK they are all just about the same except for ratios.

argatoga

jgrewe do you have any pictures? What year B2000? I've got an '86 RX-7 N/A gearbox. The B2000 tail shaft doesn't look like it will match.

On second thought I did buy the tranny/engine from eBay, I wonder if it is a Mazda R type. It is a NA engine so I assumed it was the NA gearbox.

argatoga

If it is a Turbo tranny (I'll need to look tomorrow as I don't remember exactly what it looks like off the top of my head) is there any way to shorten it?

rotarydude

iTrader: (2)

It should be a standard NA tranny. for it to be a T2 tranny there would have to have been some modifications done already. The B2000 tail shaft trick should work just fine I have been a part of (but never done it myself) where we used the SA (79-80) Rx7 tailshaft housing on a 81-3 tranny to basically do the same thing. It should be easier with the B2000 part because the shift rods are more compatible than from the early rx7s

argatoga

Are there any particular markings I can look at to determine which transmission it is? Because the B2000 tailshaft housings aren't looking compatible.

jgrewe

iTrader: (1)

Just look at the bolt pattern to the rest of the tranny. IIRC the shape of the housings are different because of mounting and shifter positon being close to the gear set.

The T2's have a 'flat' ribbed plate that bolts to the bottom and ribs around the center section. The rest of the RX7 boxes don't have to plate that unbolts to expose the gears. The earlier boxes (RX4 etc) look like the T2 boxes.

argatoga

O.K. it is a NA transmission then as there is no plate to expose the gears. I'll go and post a picture tomorrow.

argatoga

Here are some pictures. First the one that came with the 13B NA:




Now the one from the JDM 12A the car originally had:



I don't mind which one as long as it can be shortened an appreciable amount.

jgrewe

iTrader: (1)

Looks like either one would work. Look at the 'center' section right where the tail housing attaches, don't worry about the shifter style or mounting area. That 1" or so thick plate in the middle will have the same bolt pattern as the B2000 tranny.