dakos Posted October 1, 2009 Share Posted October 1, 2009 hello, i was thinking to replace my 97 gt's rear differential with a 4.4 ratio one do i need tot do any other modifications or just to do the replacement?? the car in manual transmission thank you! Link to comment Share on other sites More sharing options...
GLCraig Posted October 1, 2009 Share Posted October 1, 2009 You would need to have a front differential with the same ratio. Link to comment Share on other sites More sharing options...
idosubaru Posted October 1, 2009 Share Posted October 1, 2009 there's two differentials - front and rear. you would need to either run one (so make it FWD or RWD) or install 4.44's into the front diff. problem is the front diff being integrated with the trans and requiring some fairly complicated backlash adjustment is not easy to swap. rear is simple. Link to comment Share on other sites More sharing options...
dakos Posted October 1, 2009 Author Share Posted October 1, 2009 thanks for the replays ..looks like i'll have to wait until i'll do a full swap... will be a 92 2.2 EJT compatible to swap in my 97 legacy ? i mean a full swap engine and transmission..? Link to comment Share on other sites More sharing options...
edrach Posted October 1, 2009 Share Posted October 1, 2009 thanks for the replays..looks like i'll have to wait until i'll do a full swap... will be a 92 2.2 EJT compatible to swap in my 97 legacy ? i mean a full swap engine and transmission..? Some of the recent model Foresters have a 4.444 drivetrain with the manual transmission. Check out the transmission charts in the USRM to see what's available. Link to comment Share on other sites More sharing options...
johnceggleston Posted October 1, 2009 Share Posted October 1, 2009 the 97 GT 5 spd has a 4.11 final drive ratio, as far as i know that's the lowest gearing in a manual trans after 1990, in the US anyway. to get to a 4.44 you would need to swap the ring gear in the front diff and swap in a rear differential from a 4.44 auto trans. the good news is that you don't have to change the pinion and the 37 tooth ring gear (instead of the 40 tooth currently) should be readily available. i assume it will fit in the 5 speed case. it would be easier to get smaller wheels/ tires. Link to comment Share on other sites More sharing options...
Gloyale Posted October 1, 2009 Share Posted October 1, 2009 (edited) the 97 GT 5 spd has a 4.11 final drive ratio, as far as i know that's the lowest gearing in a manual trans after 1990, in the US anyway. to get to a 4.44 you would need to swap the ring gear in the front diff and swap in a rear differential from a 4.44 auto trans. the good news is that you don't have to change the pinion and the 37 tooth ring gear (instead of the 40 tooth currently) should be readily available. i assume it will fit in the 5 speed case. This doesn't work. You cannot mix and match rings and pinions. even if the Pinion has the same # of teeth. The cut of those 9 teeth will be different. You also have it backward. 9 tooth pinion and 40 tooth ring = 4.44 (what he wants) 9 tooth pinion and 37 tooth ring = 4.11 (what he has) Also to the OP, you are looking for LOWER gear ratio, not higher. (bigger # = lower ratio) Edited October 1, 2009 by Gloyale Link to comment Share on other sites More sharing options...
edrach Posted October 1, 2009 Share Posted October 1, 2009 the 97 GT 5 spd has a 4.11 final drive ratio, as far as i know that's the lowest gearing in a manual trans after 1990, in the US anyway. Per the transmission chart in the USRM, the '04 and '05 XT Foresters have a 4.444 transmission along with the '04 Turbo Baja. A fair number of JDM transmissions come with a 4.444 ratio. Link to comment Share on other sites More sharing options...
Fairtax4me Posted October 1, 2009 Share Posted October 1, 2009 Do you want to go faster, or do you want better acceleration? Link to comment Share on other sites More sharing options...
dakos Posted October 1, 2009 Author Share Posted October 1, 2009 i want it a little bit faster and also i don't like raving the engine doing 60-70km/h in the city... for 60km/h it goes up to 2500 rpm and for 70 almost ot 3000 rpm i have also a 92 legacy turbo , manual that has a a hi ratio diff. and it doest go more than 2000 rpm for 60 km/h on the 4 speed... Link to comment Share on other sites More sharing options...
johnceggleston Posted October 1, 2009 Share Posted October 1, 2009 You also have it backward. 9 tooth pinion and 40 tooth ring = 4.44 (what he wants) 9 tooth pinion and 37 tooth ring = 4.11 (what he has) i corrected my post, i hate posting errors and bad information. This doesn't work. You cannot mix and match rings and pinions. even if the Pinion has the same # of teeth. The cut of those 9 teeth will be different. i thought that originally, but i feel like someone here posted something about doing it or something similar. but i just checked the pinion part numbers and they are in fact different. thanks for correcting my mistake. Link to comment Share on other sites More sharing options...
edrach Posted October 1, 2009 Share Posted October 1, 2009 i want it a little bit faster and also i don't like raving the engine doing 60-70km/h in the city...for 60km/h it goes up to 2500 rpm and for 70 almost ot 3000 rpm i have also a 92 legacy turbo , manual that has a a hi ratio diff. and it doest go more than 2000 rpm for 60 km/h on the 4 speed... 70KM/hr is 42mph and you're at almost 3000 rpm; that doesn't sound right. I have a '97 Impreza with a 4.111 gearbox and diff and at 3000 rpm in 5th gear I'm going about 60 mph (100 KM/hr). I'll check on that tomorrow when I'm back out on the highway. Link to comment Share on other sites More sharing options...
Fairtax4me Posted October 1, 2009 Share Posted October 1, 2009 (edited) The pitch and angle of the teeth will be different from one set to another. Mixing and matching may work... for a few miles... :-p i want it a little bit faster and also i don't like raving the engine doing 60-70km/h in the city...for 60km/h it goes up to 2500 rpm and for 70 almost ot 3000 rpm i have also a 92 legacy turbo , manual that has a a hi ratio diff. and it doest go more than 2000 rpm for 60 km/h on the 4 speed... Then you want a LOWER differential ratio. A 4.44 ratio is 4.44 turns of the input shaft to 1 turn of the axle. Best expressed as 4.44:1. Without going into too much detail (math) the lower the ratio, the fewer the number of revolutions of the engine at a given speed. If your ratio is 4.10 right now, the 4.44 will make the engine run at 3250 rpm at 70km/h. A 3.50 ratio will get you engine speeds around 2600 rpm. The reason your other car runs at a lower rpm is probably because of the gears in the transmission. Tire size can also play a big part in engine speed. 70KM/hr is 42mph and you're at almost 3000 rpm; that doesn't sound right. I think it's about right for 4th gear though. Edited October 1, 2009 by Fairtax4me Link to comment Share on other sites More sharing options...
edrach Posted October 2, 2009 Share Posted October 2, 2009 (edited) I think it's about right for 4th gear though.I've got a 4.11 rear on my '97 Imp and I'm turning 2700 rpm at 70KM/hr in 4th. Tires are 195/60-R15 snow tires. Edited October 2, 2009 by edrach Link to comment Share on other sites More sharing options...
dakos Posted October 3, 2009 Author Share Posted October 3, 2009 Then you want a LOWER differential ratio. A 4.44 ratio is 4.44 turns of the input shaft to 1 turn of the axle. Best expressed as 4.44:1. Without going into too much detail (math) the lower the ratio, the fewer the number of revolutions of the engine at a given speed. If your ratio is 4.10 right now, the 4.44 will make the engine run at 3250 rpm at 70km/h. A 3.50 ratio will get you engine speeds around 2600 rpm. The reason your other car runs at a lower rpm is probably because of the gears in the transmission. Tire size can also play a big part in engine speed. I think it's about right for 4th gear though. i guess you are right...could be the gear box on the 92 that make's run faster alt lower rpms... regarding the tire size am still on the factory specs 205/55/16... how interchangeable are the parts between old models and new ones?? can i do a full swap between the 92 and 97? i'll get the turbo engine like that on my 97 gt ) Link to comment Share on other sites More sharing options...
johnceggleston Posted October 3, 2009 Share Posted October 3, 2009 (edited) This doesn't work. You cannot mix and match rings and pinions. even if the Pinion has the same # of teeth. The cut of those 9 teeth will be different. i just read a post about converting a 3.7 lsd rear into a 3.9 lsd, or vice versa, i forget. is this just swapping the locking part or the ring gear as well?? if ring gear, wouldn't the pinion teeth be cut different? trying to learn, john Edited October 3, 2009 by johnceggleston Link to comment Share on other sites More sharing options...
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