So Ive been doing alot of research for a 6spd option for Ford/Mazda vehicles using the G-series transmission, be it G5,G15,G25,G35. Heres what Ive come up with so far::
For those of us that have torn into G series trannies we all know 90% of everything is interchangeable.. Ive found out that 2009+ Mazda6 2.5 6spd transmissions are G6M. From what Ive been able to tell, BP/KL/FS bell housings will be able to swap onto the G6M 6spd gear box without issue.
The top mount brackets would need to be fabricated, but would be fairly simple seeing as they are stamped steel brackets. The Rear mount wouldnt be an issue because on BP applications It is bolted to the bottom of the case, and FS/KL to the bellhousing side of the trans, which you would retain.
The front mount bolts to the bellhousing as well so not an issue.
This generation of the G-series is also cable actuated shifting, so an appropriate shifter box/cables would need to be found as well. Axles are 28 spline so stock axles for FS or KL cars or 94-97 Sephia BP axles should work fine for BP applications. Input shaft is also the same as all G-series; 22 spline 15/16"
All I can find that doesn't line up between the 2 bell housings are the 2 dowel pins that are commonly found on older G-series are not existent on the new G6M 6spd box. Not a problem at all as far as I'm concerned.
The 2 dowel pins in question I've marked in red. but compare the KL bellhousing to the MZR bell housing as far as the mounting points at the case halves. I see this being entirely possible, and Ive found a 6spd 2009 transmission locally for $650. Im SERIOUSLY considering picking it up and experimenting.
Gear ratios are as Follows:
1st:: 3.454
2nd:: 1.842
3rd:: 1.310
4th:: 1.030
5th:: 0.837
6th:: 0.717
FD:: 4.388
I'll use a MSP G series as an example::
1st:: 3.307
2nd:: 1.842
3rd:: 1.310
4th:: 0.970
5th:: 0.755
FD:: 4.105
So shorter 1st, same 2nd and 3rd gear, with 4th gear being the same as a BP G series. (I always hated the RPM drop into 4th gear on FS cars) Overall a pretty sporty trans with the 4.38 final.
On to the pics:
Give me some feedback, tell me what you guys think! I really think this can happen!
For those of us that have torn into G series trannies we all know 90% of everything is interchangeable.. Ive found out that 2009+ Mazda6 2.5 6spd transmissions are G6M. From what Ive been able to tell, BP/KL/FS bell housings will be able to swap onto the G6M 6spd gear box without issue.
The top mount brackets would need to be fabricated, but would be fairly simple seeing as they are stamped steel brackets. The Rear mount wouldnt be an issue because on BP applications It is bolted to the bottom of the case, and FS/KL to the bellhousing side of the trans, which you would retain.
The front mount bolts to the bellhousing as well so not an issue.
This generation of the G-series is also cable actuated shifting, so an appropriate shifter box/cables would need to be found as well. Axles are 28 spline so stock axles for FS or KL cars or 94-97 Sephia BP axles should work fine for BP applications. Input shaft is also the same as all G-series; 22 spline 15/16"
All I can find that doesn't line up between the 2 bell housings are the 2 dowel pins that are commonly found on older G-series are not existent on the new G6M 6spd box. Not a problem at all as far as I'm concerned.
The 2 dowel pins in question I've marked in red. but compare the KL bellhousing to the MZR bell housing as far as the mounting points at the case halves. I see this being entirely possible, and Ive found a 6spd 2009 transmission locally for $650. Im SERIOUSLY considering picking it up and experimenting.
Gear ratios are as Follows:
1st:: 3.454
2nd:: 1.842
3rd:: 1.310
4th:: 1.030
5th:: 0.837
6th:: 0.717
FD:: 4.388
I'll use a MSP G series as an example::
1st:: 3.307
2nd:: 1.842
3rd:: 1.310
4th:: 0.970
5th:: 0.755
FD:: 4.105
So shorter 1st, same 2nd and 3rd gear, with 4th gear being the same as a BP G series. (I always hated the RPM drop into 4th gear on FS cars) Overall a pretty sporty trans with the 4.38 final.
On to the pics:
Give me some feedback, tell me what you guys think! I really think this can happen!
Last edited:
