Mazda '93 V6 626 M/T transmission compatibility with MX3

MikeMcLarenF1 · Post by **MikeMcLarenF1** » September 25th, 2007, 4:28 pm

Hi, I'm a brand spanking new member, starting my first post already with an engine swap question. I just bought an '94 MX3 GS in red like 3 days ago. I'm planninng to do the KL-DE swap since my V6 and tranny is on its last legs, and I could benefit from a little bit more torque.

Now here's the situation:

I spotted a '93 626 ES trim w/ a spare V6 around my area. There have been enough posts around here to let me confirm that the ENGINE will fit.

I just wanted to know, does the 626 ES 5spd transmission fit? Is it NOT recommended? The spare engine is meant to go into the 626, and so is the 5spd tranny. I just see all the transmission posts directed at the MX6 and Probes, not exactly at the 626's. For all I know it might fit right but I'm just not sure about the axels needed and stuff.

I'd be happier to use the 626 tranny since mine is known to have worn out syncros and hopefully the one from the 626 is still good.

could someone point me out?

I'm mostly worried about:

- which wiring harness to use
- which ECU alternatives I can use instead of the stock KL
- any major cooling modifications required
- which CV axels to use if I use the 626 5spd tranny
- any mods required for the 626 tranny in general
- any mods immediately needed to fit the engine in
- possible to retain A/C still?

Tunes67 · Post by **Tunes67** » September 25th, 2007, 4:57 pm

Yes then engine and transmission will fit without issue. If going with a KLDE.. your best ECU/MAF combo will come from a Ford Probe GT. You can use your stock axles with the 626 trans and its actually the Best tranny to get for freeway useage. It cruises at a lower RPM than the other V6 trannies that are availble ( Probe, Millenia, MX-3, MX-6 will all fit)

Shouldnt need any cooling modifications.. but replacing the stock 94 Radiator with a new one wouldnt be a bad idea. Also.. while the engine is out of the car, good idea to replace the timing belt and water pump at that time since they are MUCH easier to access outside of the car. And you shouldnt have any trouble retaining your A/C. Just dont crack the lines when you pull the K8 and just bolt the compressor right up to the replacement KLDE.

The engine block between the 1.8 K8 and the 2.5 KLDE are identical.. the differences are on the inside of the engine. The wiring harness is the same as the Probe so the ECU & MAF are plug n play. If it will bolt to one engine.. it will bolt to the other.. no major mods needed.

If you are thinking headers and redoing your exhaust.. replace the exhaust manifolds with headers while the engine is out.. again.. MUCH easier to do with the engine out than while the engine is in the car.

Tunes67

Tunes67 · Post by **Tunes67** » September 25th, 2007, 5:01 pm

Oh yeah.. welcome to the board

Might want to take a bit of time and read about your MX-3 on the http://www.mx-3.com homepage.. LOTS of information on that page including a link to an online shop manual which will come in mighty useful while your working on your car

Tunes67

mx3autozam · Post by **mx3autozam** » September 25th, 2007, 6:12 pm

Welcome to the board man. Glad to see you got your project figured out. Have you considered a KLZE. the de will do a nice job in an mx3 but man the KLZE will make it alot more fun.

The 626 tranny is the same as the mx-6. The difference is the Final drive is taller at 4.11 and the mx3 and ford probe are 4.39. Its totally up to you. with the 626 you will be at a lower rpm and be a tad cheaper on gas. You top speed will be about 10km/h faster. 2nd gear will seem pretty long and can amke it fun to drive.

The mx3 4.39 gears it will be the best if you wanna accelerate fast. weather that be for drag racing road racing or autocross. But then on the other hand if your current tranny is shot and your getting a 626 tranny with the klde then thats cool since its a good price i would assume.

You can also take the 5th gear from your mx3 trans and swap it into the good 626 trans then you'd have 4.39 geraing like the stock mx3.

Yoda · Post by **Yoda** » September 26th, 2007, 12:37 pm

The donor car for the engine and tranny for my car way back in 1997 was a early '93 626ES without the "warranty" rework to the heads and pistons. The thing you will find is the 4:11 gears are a better match to the torque of the KL -DE than the 4:39. I used all the hardware from the 626 and have the guys at Lazer load a tuned KL file onto a new EEPROM in my K8 ECU

MikeMcLarenF1 · Post by **MikeMcLarenF1** » October 3rd, 2007, 7:08 pm

woa.... so much good info, i created a new thread to ask Q's and didn't realize most of my new Q's been answered too. deleted the thread already!

Nice, actually, the motor turned out to be from a '93 Probe GT, so does that mean the cam rework issue is solved? but yeah, I still have 2 trannies, 626 and the Trobe GT to choose from. I guess I will stick with the 626 for that highway mileage??

Oh.. as for the DE vs ZE, yeah I concidered a ZE, but, I paid 800 bucks plus the tranny for the DE.... I already think that's way too much. I bet JK's gonna charge me over a grand for the ZE so.. forget it.

I'm not much of a hardcore driver, I just want to make the most out of my car within a reasonable budget, hence the DE choice and the 626 tranny... don't want to empty my pockets for this car just yet!

mx3autozam · Post by **mx3autozam** » October 3rd, 2007, 10:52 pm

Whats this cam rework you guys talk about? is it the friction gear by any chance?

MikeMclarenf1
i'll sell you a 4.39 geared tranny with a limited slip diff

mazdags94 · Post by **mazdags94** » October 29th, 2007, 7:21 am

mx3autozam wrote:Whats this cam rework you guys talk about? is it the friction gear by any chance?

MikeMclarenf1
i'll sell you a 4.39 geared tranny with a limited slip diff

mx3autozam- let me know how much you would be willing to sell that tranny for. PM me if you could as I need a 5 spd soon! Thanks

Yoda · Post by **Yoda** » October 29th, 2007, 12:29 pm

mx3autozam wrote:Whats this cam rework you guys talk about? is it the friction gear by any chance?

Actually it wasn't a cam rework but a head re-work. The problem was with poor quality gas the pistons would develope carbon deposits and the piston would slap the head. Mazda contracted SLP (yes the SS Camero people) to modify the heads opening up the combustion chamber but at the same time reducing the compression ration slightly. The engine I got was in a side impact collision before the heads were exchanged and may have been a production freak as it also had flat tops. Never had any carbon problems untill the valve seals started to go.