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If all G series transmissions, especially the G25M-R (FWD) and the G25MX-R (4wd) have interchangeable gears, then a large number of custom transaxles can be made for various purposes.
From what I have read, any FWD (2wd) or any FWD gears from a 4wd transaxle will fit into a G25M transmission case.
Does any know this to be 100% true, especially the FWD gears from a 4wd gearbox fitting????
My primary interest is in making a specific gear box for use in drag racing.
Here are the gears and final drives available for G series transmissions:
G25M-R G25MX-R
1st 3.307 (3.666) 3.454 (3.307) (3.666)
2nd 1.833 1.833 (2.187)
3rd 1.310 (1.160) 1.310 (1.680) (1.233)
4th 1.030 (0.970) (0.860) 0.970 (1.093) (0.914)
5th 0.795 (0.755) (0.680) 0.717 (0.795) (0.755)
final 4.105 (3.850) (4.388) 4.214 (4.388)
G15M-R G35M-R G66M-R G5M-R
1st
2nd 1.842 2.059
3rd 1.392
4th
5th 0.837
final 3.409
From Mazda Motor Sport final drive R&P 4.88
Cars with FWD G series transaxles. Later year cars have better gears (see below notes)
87 323 GT
90-94 Protege LX
91-94 Capri XR2
91-96 Escort GT, LX-E and Tracer LTS
92-94 MX3 GS
93-97 Probe GT, MX6 LS, 626 ES
95-95 Protege ES
97+ Kia Sephia
99+ Protege ES
01+ Protege ES
01+ Protege LX 2.0
02+ Protege (all models)
02+ Protege 5
01- MP3
03 Mazdaspeed Protege (with LSD)
NOTES from PAR
Since the late 80’s, the G25/G5M transmission has been fitted to a number of vehicles including the 323/Familia, 626/MX6, and others. The G25/G5M series are a 5MT with variants including a number of gear ratio selections and varying final drive ratios. Throughout the model’s lifespan, single cone synchronizers were used early on with the gradual fitment of double cone synchronizers fitted to the later vehicles. This is the transmission of choice when the BPT engines or turbochargers are fitted to the BP engines in the Mazda 323/Familia/Protege or Ford Escort/Laser vehicles.
Although much stronger than the smaller F-Series transmissions, the G-Series torque capacity is still not sufficient to handle the extra load and shock provided by the fitment of more powerful engines and aggressive clutches with the most common failures being 3rd/4th gears, transmission case and broken differentials. The most notable weaknesses in the G-Series transmisssions is the general strength of the 2nd~3rd gear, differential planetary gears and pin. With more powerful vehicles, the case structure becomes a problem with the thrust load provided by the helical gears sometimes causing case failure including cracks in the housing and sometimes destructive failure of both housing and gearset
From what I have read, any FWD (2wd) or any FWD gears from a 4wd transaxle will fit into a G25M transmission case.
Does any know this to be 100% true, especially the FWD gears from a 4wd gearbox fitting????
My primary interest is in making a specific gear box for use in drag racing.
Here are the gears and final drives available for G series transmissions:
G25M-R G25MX-R
1st 3.307 (3.666) 3.454 (3.307) (3.666)
2nd 1.833 1.833 (2.187)
3rd 1.310 (1.160) 1.310 (1.680) (1.233)
4th 1.030 (0.970) (0.860) 0.970 (1.093) (0.914)
5th 0.795 (0.755) (0.680) 0.717 (0.795) (0.755)
final 4.105 (3.850) (4.388) 4.214 (4.388)
G15M-R G35M-R G66M-R G5M-R
1st
2nd 1.842 2.059
3rd 1.392
4th
5th 0.837
final 3.409
From Mazda Motor Sport final drive R&P 4.88
Cars with FWD G series transaxles. Later year cars have better gears (see below notes)
87 323 GT
90-94 Protege LX
91-94 Capri XR2
91-96 Escort GT, LX-E and Tracer LTS
92-94 MX3 GS
93-97 Probe GT, MX6 LS, 626 ES
95-95 Protege ES
97+ Kia Sephia
99+ Protege ES
01+ Protege ES
01+ Protege LX 2.0
02+ Protege (all models)
02+ Protege 5
01- MP3
03 Mazdaspeed Protege (with LSD)
NOTES from PAR
Since the late 80’s, the G25/G5M transmission has been fitted to a number of vehicles including the 323/Familia, 626/MX6, and others. The G25/G5M series are a 5MT with variants including a number of gear ratio selections and varying final drive ratios. Throughout the model’s lifespan, single cone synchronizers were used early on with the gradual fitment of double cone synchronizers fitted to the later vehicles. This is the transmission of choice when the BPT engines or turbochargers are fitted to the BP engines in the Mazda 323/Familia/Protege or Ford Escort/Laser vehicles.
Although much stronger than the smaller F-Series transmissions, the G-Series torque capacity is still not sufficient to handle the extra load and shock provided by the fitment of more powerful engines and aggressive clutches with the most common failures being 3rd/4th gears, transmission case and broken differentials. The most notable weaknesses in the G-Series transmisssions is the general strength of the 2nd~3rd gear, differential planetary gears and pin. With more powerful vehicles, the case structure becomes a problem with the thrust load provided by the helical gears sometimes causing case failure including cracks in the housing and sometimes destructive failure of both housing and gearset