FunK73

iTrader: (6)

So its time for me to bite the bullet. I need to convert my rx7 from an automatic to a manual. Its a 1984 GS, and i already have the counterweight, flywheel and clutch squared away. Now I know what I need as far as the obvious things, AKA the transmission itself, pedal box etc. However I would like a list of anything I might be overlooking, I.E. are the transmission mounts going to be the same for any particular transmissions, will i need a new drive shaft, what all do I need as far as clutch hydraulics, etc.

kickinwing

I know you will need a clutch master and slave cylinder, as well as the lines the solid one that runs on the firewall and the soft line that goes into the slave cylinder. you will also probably need a different interior trim piece that surrounds the shifter unless you want to run without one.

Glazedham42

iTrader: (4)

There are more threads on this you can find in a search. I have a list made up already in the first thread I posted below. Just follow the links and use my old info. I did this to my 1985 GS several years ago. The only thing that doesn't bolt up is the crossmember for the manual trans. You have to make some steel adapter plates, but it's not hard at all. You will find pictures of the adapter plates if you read through the threads below. The hardest part of the swap is bolting in the new pedal box.

https://www.rx7club.com/showthread.p...ight=auto+swap

https://www.rx7club.com/showthread.p...ight=auto+swap

https://www.rx7club.com/showthread.p...ight=auto+swap

https://www.rx7club.com/showthread.p...ight=auto+swap

https://www.rx7club.com/showthread.p...ight=auto+swap

https://www.rx7club.com/showthread.p...ight=auto+swap

https://www.rx7club.com/showthread.p...ight=auto+swap

https://www.rx7club.com/showthread.p...ight=auto+swap

FunK73

iTrader: (6)

So even if I have the mount for the manual tranny I have to still fabricate something?

Glazedham42

iTrader: (4)

Aww, man I didn't notice that the pictures were missing. You are basically making two rectangular steel plates 1/4" thick, about 1" wide, and 3-4" long. Put two holes in each of the plates, one hole in each end. They are basically adapters to make up for the differences in length between the two transmissions. To figure out the length, sit each transmission on the floor on its bellhousing. Measure from the floor, up to the point where the transmission mounts to the crossmember. The automatic transmission will have a larger measurement since it is longer.

Subtract the manual transmission length from the auto transmission lenght. That's how far apart your bolt holes need to be. If I have totally confused you, let me know. I can provide a quicky diagram.

FunK73

iTrader: (6)

I think I got it but a diagram would help. Do you happen to have any pictures of the plates on your car either? That would also help immensely.

Glazedham42

iTrader: (4)

Found some old pictures of the mounts on my car. These pictures are with the 5 speed transmission swapped in. You can see how the steel plates make up for the difference in length between the two transmissions. The big fender washers help to keep the load spread out against the brackets.

Also, if you look very carefully you can see some big fat washers stacked up underneath the rubber transmission mount. These are important. They are a total of 1/4" thick, just like the two adapter plates are. The purpose of the stacked washers is to keep the transmission in line. If you think about it, the two steel plates are going to throw the alignment of the transmission's tail off by 1/4". It probably wouldn't make a huge difference since the driveshaft has u-joints in it, but over time it may cause them to wear faster. By putting 1/4" worth of washers underneath the transmission mount, you gain back that distance, and keep everything aligned like it should be to begin with. Make sense?

Glazedham42

iTrader: (4)

Also, here is the parts list for reference. You are also going to need the speedo cable from the 5 speed car. The transmission end of the cable is different. Your auto cable won't work.

1) 5 speed transmission from 83-85 Rx-7
2) Crossmember and transmission mount from 5spd
3) Driveshaft from 5 speed
4) Pedal box from 5 speed
5) 5 speed wiring harness (5 wires?)
6) Starter from 5 speed
7) Unplug the auto trans next to the ECU in the passenger footwell
9) Your auto counterweight
10) Flywheel. I recommend lightened flywheel since you already have a counterweight.
11) New pilot bearing and pilot bearing seal for flywheel
12) Clutch disc and pressure plate
13) Throwout bearing in M/T.
14) Top dust cover plate for engine. Take from 5 speed donor car
15) Steel plates to make up for the different mounting points of the crossmembers. (4"-4.5")
16) Clutch master cylinder.
17) Clutch hydraulic hard line. Take from donor car.
18) Clutch hydraulic soft line. Get a new stainless braided one from Mazdatrix. Only $20.
19) Shifter from the 5 speed donor car
20) Speedometer cable from 5 speed donor car

KansasCityREPU

iTrader: (9)

I just went through this conversion myself. I went a different route then Glazedham42. I haven't driven mine yet so I can't speak as far as how it works. I like Glazedham42 idea. It's seems more simple and easier to execute then mine. I might be switching to his if mine doesn't work. I used the auto trans mount. I measured the holes wrong and had to drill new ones as you can see. The holes closest to the edge are the ones to use. I also bought new rubber trans mount and hardware from Mazda. I also powder coated every part the I could put in my powder oven. The plate is made from of 3/8" plate.

You also do not need to whole pedal box. There is a long bolt the holds the pedals in. Just remove the bolt and the pedals will come out. Also get all the clutch switches (2 of them).

I have more picture with measurements. Just send me your email address.

FunK73

iTrader: (6)

Is the counterweight built into the flywheel on the stock ones? Cause i have a stock flywheel at my fingertips for free. Also, what does the 5 spd wiring harness for/look like? I'm assuming its just for the reverse lights etc. And the stock auto speedo cable is a no go too?

Glazedham42

iTrader: (4)

You can use a stock flywheel as long as it matches up to the correct engine year. So, in your case you'll need to use a flywheel from a 1984-1985 12A. The earlier engines had different rotor weights, and I think the internal balancing of the flywheel is different. Use a 1984-1985 flywheel to be safe.

The 5 speed wiring harness starts near the steering box on the driver's side. It runs down the driver's side of the engine, past the starter, down to the transmission. Yes, it controls the reverse lights. I believe that the harness may have a couple of connectors that attach to the starter too. It's been a while, so I can't remember for sure on that.

The auto speedometer cable has a different transmission end on it if I remember correctly. You need the cable from the 5 speed so that it has the correct end to fit into the 5 speed transmission.

KansasCityREPU

iTrader: (9)

The auto speedo has the same ends as the manual. The only difference is that it is way to long. It will work, but I suggest getting one from a donor. I'm still looking for a speedo cable. I would like to find a new one if possible.

FunK73

iTrader: (6)

Ok good to know. Now i gotta find a flywheel =/

Rx-7Doctor

iTrader: (13)

Quote from Kansas-

You also do not need to whole pedal box. There is a long bolt the holds the pedals in. Just remove the bolt and the pedals will come out. Also get all the clutch switches (2 of them).



Post a picture of your stock automatic brake pedal so we can see how close it sits to the clutch pedal please.


more recent thread on the swap-

https://www.rx7club.com/1st-generation-specific-1979-1985-18/auto-trans-manual-trans-swap-part-ii-has-begun-783169/

KansasCityREPU

iTrader: (9)

I used the manual break pedal and the auto pedal box (I believe the boxes are the same). I'll get a pic of the stock auto brake pedal in the box and another pic with the manual brake/clutch pedal combo. The main difference is that the auto uses a shorter bolt to hold the pedals in.

FunK73

iTrader: (6)

From what I have found so far, it appears the 83-85 flywheels have the same weight? Am I reading this right? The flywheel I have is for an 83

http://www.mazdatrix.com/r-rtrwgt.htm

KansasCityREPU

iTrader: (9)

Yes the 83-85 12A flywheels have the same weight.

Here is the link

http://www.mazdatrix.com/faq/flywheel.htm