Official Transmission Swap Information (Update 21/05/2010)

[NANO91]

Working on my transmission swap, now I have gotten all parts just one thing I don't know to get my speedo working on my 92 rs its a mechanical and the g series is digital. Is the a speedo cable on a mx3 that will go into the g series and work with my gauge? Or do I just get a new cluster from a 94?

[Ryan]

I have just discovered that everyone with a MTX swap and an ATX engine harness has a VRIS issue where #1 stays open and #2 stays closed all the time.

Working on resolving it, its a result of the wiring being different...

[Tavman_1213]

So in doing my BPT swap an going to a G series transmission I have found out that there are some escort GTs that have BPs in them that came mated to a F series transmission!! They also use a half shaft and there is a difference between the F series half shaft an the G series half shaft!! The differences are the length an the spline count goin into the transmission!! The G series one is 3/4" longer an has 26 spline count on both ends where as the F series has 24 on the transmission side with 26 on the axle side!!
Be warned they look exactly the same if you didnt know there was a difference between the two!! Here's a couple of pictures to show the difference.

In this picture the G is top one an the F is on the bottom!

This is the F series in the transmission

This is the G series in the transmission

Both cars were 90-94 ford escort GTs with BPs in both!! Hopefully people can learn from my mistake!!

[Ryan]

Interesting indeed.

It seems the common theme is the diameter of the axles, the G series is visibly thicker, so are the actual axles.

[Josh]

I would think that they may have been swapped out at some point. you have to run a SOHC flywheel too. seems odd. I would not even bother with an egt trans, I would try and find yourself a Kia trans. you will be happy you did in the long run.

[Tavman_1213]

Interesting indeed.

It seems the common theme is the diameter of the axles, the G series is visibly thicker, so are the actual axles.

The axles are actually the same diameter just different lengths. Same spline count also
I would like a Kia transmission but I have 2 escort GT ones already so I will stick with them till I brake one! I plan to rebuild the other(switch gears, LSD the whole she bang!)

[Nd4SpdSe]

Got a buddy with a Kia Rio (B6 turbo's) and his issue with it is that it's a cable clutch I believe, so he had very limited choices for clutches

[stevesei]

Current additions and a question:

1. The 94-up RS (1.6) came with an F25M-R transmission, intermediate shaft, and roughly equal length half-shafts. BP (1. engines have the same setup, but for the G-series MTX.

2. The later MX-6 V6 MTX came with a 2-bolt intermediate shaft which is otherwise identical to the GS intermediate shaft. The difference is the bracket, which is taller and provides more leverage to resist torque, hence no need for 3 bolts. My 95 Millenia V6 block came with holes drilled and tapped for both half-shafts. Everything fits and works perfectly.

3. The K8 flywheel fits the KL series engines and WILL accept the KL 225mm clutch. The K8 flywheel is ~17lb, the KL flywheel is ~22-26lb.

4. GRANTED that all V6 G-series manual transmissions interchange. Does anyone know if internal parts from the G-5M-R and the G-25M-R transmissions will interchange, especially: gears, primary and secondary shafts, synchros? Or are the changes minor, such as revised synchros, shift forks, etc. that are different, but will fit?

[crazycanadian]

Current additions and a question:

1. The 94-up RS (1.6) came with an F25M-R transmission, intermediate shaft, and roughly equal length half-shafts. BP (1. engines have the same setup, but for the G-series MTX.

2. The later MX-6 V6 MTX came with a 2-bolt intermediate shaft which is otherwise identical to the GS intermediate shaft. The difference is the bracket, which is taller and provides more leverage to resist torque, hence less need for 3 bolts. My 95 Millenia V6 block came with holes drilled and tapped for both half-shafts. Everything fits and works perfectly.

3. GRANTED that all V6 G-series manual transmissions interchange. Does anyone know if internal parts from the G-5M-R and the G-25M-R transmissions will interchange, especially: gears, primary and secondary shafts, synchros? Or are the changes minor, such as revised synchros, shift forks, etc. that are different, but will fit?

Have a look some questions will be answered..

B6T/KL transmission comparisons
http://www.mx-3.com/phpBB3/viewtopic.php?f=30&t=78191

info on how to tear down a g series..
http://www.mx-3.com/phpBB3/viewtopic.php?f=30&t=57566

Half way down another comparison and info on using 97+ SOHC escort gears in a V6 transmission..
http://www.mx-3.com/phpBB3/viewtopic.php?f=46&t=80165

B6T/BP g series have thinner ring gears.. I haven't had one side by side, but they should interchange with each other.. They will not interchange with the later V6 transmissions.... You can use some parts like shift forks, and stuff like that, but the counter shaft and the diffs wont work... The actual gears can be interchanged though..

Probe/Mx3/Escort (97+ SOHC)/626 all have thicker ring gears... These all interchange various parts and gear sets...

unknown for me are later model mazda speed protege transmissions.. I know you can use the LSD diffs in V6 transmissions, but I haven't had one apart to see what else is interchange able...

Kia BP transmissions.. have a thicker ring gear.. I have rebuilt one, but never compared it to a V6 transmission.. I believe it will interchange with the V6 stuff though...

[stevesei]

Thanks, the post on the various gearsets answers a lot of questions.I have the G-series from an FS engine 626. I want to use the 3rd, 4th, 5th gears in my MX-3 trans, as well as any updated selectors, synchros, etc. It looks like they'll all work.

I hope the other info is usable for someone!

[crazycanadian]

Thanks, the post on the various gearsets answers a lot of questions.I have the G-series from an FS engine 626. I want to use the 3rd, 4th, 5th gears in my MX-3 trans, as well as any updated selectors, synchros, etc. It looks like they'll all work.

I hope the other info is usable for someone!

Count ratios I would be curious to see pics and know what the full ratios of that transmission are...

[stevesei]

This is the FS 4-cylinder box. Ratios are SUPPOSED to be:

MX-6 (FS) & 626 (FS) / G(2)5M-R
Gear Ratios
1st 3.307:1
2nd 1.833:1 (45% rpm drop between 1st and 2nd)
3rd 1.233:1 (32% drop) (MX-3 = 1.310:1, 22% drop)
4th 0.914:1 (26% drop) (MX-3 = 1.030:1, 21% drop)
5th 0.717:1 (21% drop) (MX-3 = 0.795:1, 23% drop)

Note the more even progression of gear spacing takes advantage of the KL's torque in the lower gears while giving a 10% higher final gear ratio, REGARDLESS of the final drive ratio used.

It's the taller 3rd, 4th, and 5th I'm looking for for better spacing, more relaxed highway cruising while keeping my 4.39 for autocrossing. I will check the ACTUAL ratios when I get it apart and post them here.

[crazycanadian]

This is the FS 4-cylinder box. Ratios are SUPPOSED to be:

MX-6 (FS) & 626 (FS) / G(2)5M-R

Gear Ratios (Input:Output)
1st 3.307:1
2nd 1.833:1
3rd 1.233:1
4th 0.914:1
5th 0.717:1
Final Drive 4.105:1

It's the taller 3rd, 4th, and 5th I'm looking for for better spacing, more relaxed highway cruising while keeping my 4.39 for autocrossing. I will check the ACTUAL ratios when I get it apart and post them here.

What motor are you running in your mx3??? how much power?? depending on motor/tire size and class for autocross the 4.39 diff can be a bad choice...

I have been building my 323 for SMF class... with a KLDE swap in it running a stock mx3 transmission, I often found 2nd gear to short... It was a contributing factor in spinning #6 rod bearing due to all the high revs... This was the number #1 reason why I switched out the 4.39 diff, for the escort 3.86 diff....

the 3rd,4th,5th set up you posted is pretty much the same as the escort set up... It is really nice with the V6 on the hwy...

[stevesei]

it's a stock Milly with KL31 heads, headers, HEI, no cat, 2.25 exhaust. I estimate 185 hp at the flywheel. I have a Phantom Grip that I'm going to try so that I can utilise the 4.39 without the wheelspin I get now. If that doesn't work, I think I'll have the 4.10 final from the FS box to use.

The 3.86 is a BUNCH taller than even the 4.10! how is your acceleration in 1st?

Somebody will object to asking on this forum, but how are you setup suspension-wise? I find my car is way too soft, with too much oversteer.

[crazycanadian]

it's a stock Milly with KL31 heads, headers, HEI, no cat, 2.25 exhaust. I estimate 185 hp at the flywheel. I have a Phantom Grip that I'm going to try so that I can utilise the 4.39 without the wheelspin I get now. If that doesn't work, I think I'll have the 4.10 final from the FS box to use.

The 3.86 is a BUNCH taller than even the 4.10! how is your acceleration in 1st?

Somebody will object to asking on this forum, but how are you setup suspension-wise? I find my car is way too soft, with too much oversteer.

This is the full work log on my car... Its long, lots of info.. tons of pictures and a bunch of videos...
http://www.clubprotege.com/forum/showth ... w-whip-%29

The 3.86 diff works great... I have a KAAZ LSD in the transmissions... With a stock KLG4 swap I ran 14.46 in the 1/4mile with a 2.0 60'... My previous best 60's with a 4.39 transmission were 2.1...

You got to remember these cars are light it doesn't take a lot to get them up and moving.. Depending on how much gas I have, my car is between 2200 - 2300lbs..

Throw the phantom grip in the garbage... It wont stop your wheel spin... I have played with them in more then just mazdas... they work ok, on a street driven car that sees a little bit of "spirited" driving.. Any kind of autocross/drag racing, they stop working... They work really good at slowly destroying your diff and filling your transmission full of metal... The pressure they put on the side gears pushes them into carrier causing them to wear/eat into the carrier...

A lot of people like the Mfactory diff.. For autocross its not my first choice, but its not horrible either.. torsion style diffs require some amount of traction on both tires in order for them to work... autocross often unloads the inside tire quite a bit which can cause the diff to act like an open diff.. You can sometimes combat this by applying the brakes lightly during mid corner while accelerating (left foot braking)...

I chose the KAAZ diff because its a clutch type diff thats adjustable... There is no worry when it comes to unloading the inside tire and accelerating.. I have driven cars with torsion style diffs in them as well.. During dry events they work almost the same as a clutch diff, but during rainy events the clutch type diff out performs the torsion style diff... The KAAZ is almost double the price of an Mfactory though...

For drag racing, I would go with an Mfactory... It'll take more shock load abuse... all though with both a KAAZ or Mfactory you'll be busting other things in the transmission before you kill the diffs...


suspension wise I have done a lot.... You can look over the work log, you will find it all there..

I also run an aggressive alignment set up.. Its not very tire friendly for a daily driver...