June 22, 200817 yr first off, can i install an rx ft4wd 5speed in my hatch using the same or roughly equivalent retrofitting parts/procedures as for any ea82 d/r 5speed? they use 3.70 diffs, right? so i'd have to swap out my rear diff and wire in the front diff lock but other that than is it the same? second, are these transmissions as reliable and generally as capable off road? i know the on demand d/r 5speeds have a lower l/r, but i'm not talking climbing trees - i'm talking about when i take my hatch down old muddy sierra nevada fire roads in ca "winters." i've got buddies that get old 440 power wagons with 4.10's stuck up there so its obviously not about power or gearing. third, how would the mileage compare between a ft4wd 5 and an on-demand d/r 5? the 3.70's should at least make up for the mpg loss of ft4wd, right? finally, about the rear diff. i found a 3.70 lsd on an ea82t wagon with an auto tranny. am i setting myself up for a mess of axle spline issues or are they all the same? i really don't have the budget to buy axles on top of everything else. sorry to lump it all together but i found all these parts this afternoon, did some searching/reading and only came up with more questions...
June 22, 200817 yr Yes they are pretty much the same as the standard 5sp for installation. Low range is 1.19 to 1. normal 5sp is 1.59 to 1. Depending on how you like to drive offroad and where you like to drive it may be ok or not. Personally I find the 1.59 to 1 way too high. Wiring it up is easy enough if you make sure you have the solenoids and vac diagram. Low range lever will need some custom making. Yes they are 3.7 ratio. No there shouldn't be any mpg difference between a PT and FT gearbox. This is because Subarus don't use locking hubs on the rear so in both gearboxes the rear driveshafts and diff is still spinning even in 2WD. All the rear diffs with male splines used the same 23 spline count. Its only the front diff in the gearbox that got different spline count.
June 22, 200817 yr You ARE going to have to change the front axles - and actually you will have to build custom axles as there aren't any 25 spline front EA81 axles - they never made them. The inner DOJ cup will have to be swapped out for one with a 25 spline cup that is also compatible with the EA81 axles you have (2WD or 4WD). I can't recall just now which one's swap around - early Impreza or Legacy turbo or something like that.... They aren't good for off-road. Both the low range is too high, and the diff is 3.7 - basically giving you no low range at all as compared to a regular 5spd D/R. The 1.19:1 just gives you back what you lose with the 3.7 so you might as well have no low range at all. GD
June 25, 200817 yr Could the 3.7 parts be replaced by 3.9 parts? What about swapping the low range around?
June 27, 200817 yr been talked about and yes, with a S/R XT6 FT4WD box and a D/R FT4WD box you could make a 3.9 FT D/R box.
June 27, 200817 yr Could the 3.7 parts be replaced by 3.9 parts? What about swapping the low range around? i have pulled a few D/R cases apart and it looks like it would be a very easy swap to just switch out the Low Range shafts... will be trying it this summer. -=Suberdave=- http://www.suberdave.com
Please sign in to comment
You will be able to leave a comment after signing in
Sign In Now