Zefy Posted April 5, 2006 Share Posted April 5, 2006 alright i just got off the phone with subie jim in maple ridge and we started a lively debate... the RX trans that i have sitting under a tarp is a very nice trans... we all know and love it because it is of course FULL-TIME 4WD... he doesn't believe me on this... first lets make sure i have it right... 4WD is on ALL THE TIME... no if's and's or but's... if i were to lift up the car and drive it in mid air the front AND REAR tires will spin... basicly what i'm getting at is that it IS NOT FWD...(back end gets power aswell!) then the centre locking diff locks the front and rear together giving it a 50/50 split just like the normal 4wd's... when the centre diff is off power STILL GOES TO THE BACK WHEELS!!! saying that lots so i get my point across... now he believes different... he believes that it is FWD just like the rest of the 4wd trannies... with a couple differences... he believes the centre diff switch engages the 4wd... so to clarify... the car is in FWD UNTIL the diff switch is activated... then it becomes 4WD and locked 50/50 like a s/r trans... then with this you can run d/r in FWD... (ie. 2Lo) WHO IS RIGHT??? is the RX a FWD CAR!?!?! Quote Link to comment Share on other sites More sharing options...
Caboobaroo Posted April 5, 2006 Share Posted April 5, 2006 nope, the full time trannys are always in a 4wd mode, granted more power goes to the front wheels then the rear wheels when the diff lock is not on. When switched on, it locks its 50/50 like you said. Quote Link to comment Share on other sites More sharing options...
TheSubaruJunkie Posted April 5, 2006 Share Posted April 5, 2006 Your right.. jim doesnt know what he's talking about. FWD/4WD Cars dont have a center diff. When you pull the lever, it activates the RWD and you have 50/50 4WD.. no slippage or anything. The RX's FT4WD Trans is like any AWD system. It has an open center diff. Its not locked 50/50, but it by far is NOT FWD. Once you flip the switch your open center is now a locked center diff, and you have 50/50 like any true 4WD would. Its a wonderful thing! Subaru should have done more of it. -Brian Quote Link to comment Share on other sites More sharing options...
rallyruss Posted April 5, 2006 Share Posted April 5, 2006 you can relax Zefy. you got it all correct. I am now on my second RX and both were just as you describe. Quote Link to comment Share on other sites More sharing options...
Subi81 Posted April 5, 2006 Share Posted April 5, 2006 Depends, what year the RX transmisson is out of. I have an 85 RX transmission that does NOT have a center diff. This transmission is the same as any dual range turbo wagon transmission ie Fwd until you pull the 4wd lever then the front and rear are locked together (whatever speed the front is spining the rear is spinning as well). Transmissions are the same minus low range ratios (RX are taller) Later RX's have a "full time" 4wd system with a third diff in the center. This diff allows unequal wheel speed to occure front to back thus allowing operation on pavement. Torque is directed to the wheel that spins easiest thus the one wheel burnout is possible. Since you state that the transmission in question has the diff switch you have a later model RX trans so your friend is confused. Here is a power diagram: Quote Link to comment Share on other sites More sharing options...
naru Posted April 5, 2006 Share Posted April 5, 2006 more power goes to the front wheels then the rear wheels when the diff lock is not on. HUH? How do you figure that? Quote Link to comment Share on other sites More sharing options...
Zefy Posted April 5, 2006 Author Share Posted April 5, 2006 yee haw! see Jim over here is a suby guru as long as you don't throw anything funny at him like an RX... he's never worked on one or even seen one if i'm not mistaken... (really quite rare up here) and its off an 87 i think... or higher... but not prior to 87... this would also be the first time i've been 100% right about something with him... so this is a grand victory for me indeed!:-p oh and please... everybody chime in and once again say that i'm right... rub it in...!:-p Quote Link to comment Share on other sites More sharing options...
Caboobaroo Posted April 5, 2006 Share Posted April 5, 2006 HUH? How do you figure that? without the center diff locked, there will always be moe power going to the front wheels then the rear wheels. There's more mechanical stuff that power HAS to go through to get to the rear wheels so without it locked, there will be more power going to the front wheels. Also, the '85 and '86 RX's had a PART time 4wd tranny. Totally different then the Full Time 4wd tranny. Its the same as a regular d/r tranny BUT it has a 3.70 front diff and the low range isn't as low as the NA d/r tranny Quote Link to comment Share on other sites More sharing options...
4x4_Welder Posted April 5, 2006 Share Posted April 5, 2006 Actually, as an awd, whatever wheel has the least traction will get the most power, which is why they seem to be front biased- as you launch, the vehicles center of gravity shifts to the rear, weight comes off the front and is added to the rear, and the front tires spin. Kinda crappy concept, IMO. Quote Link to comment Share on other sites More sharing options...
GeneralDisorder Posted April 5, 2006 Share Posted April 5, 2006 That's why when you launch, you lock the diff. Call it what you want, it's a legacy "AWD" transmission with EA bell-housing. Some early non US legacy transmissions also had the diff lock and 1.2:1 low range. And yes - the 85/86 RX was not AWD - it was part time, but with a 1.2:1 low range. So was the EA81 RX Coupe (JDM only). GD Quote Link to comment Share on other sites More sharing options...
Subaru Jim Maple Ridge Posted April 5, 2006 Share Posted April 5, 2006 It appears that I stand corrected. I'll have to prove it for myself ( with Zefy present) by inserting a drive shaft in the rear and turning the input shaft. The tranny has an electric over vacuum actuator operating a shifter at the rear of the tranny, the same as all of the single range 4WD 5speeds. When I saw this tranny, I assumed that it was a dual-range with the 4WD function removed from the transfer lever. Doesn't look like Zefy is going to let this one go for a while. Quote Link to comment Share on other sites More sharing options...
GeneralDisorder Posted April 5, 2006 Share Posted April 5, 2006 The vacuum device at the rear is the center diff lock actuator. It does not engage 4WD, but rather eliminates the center diff. GD Quote Link to comment Share on other sites More sharing options...
robm Posted April 5, 2006 Share Posted April 5, 2006 Zefy, where the heck did you get one of those trannies in Canada? Did you import it? Do you have plans for it, or do you want to sell it to someone who could really use it? (Assuming the weather ever goes back to normal up here in Terrace...) My AWD Corolla had this setup. It works way better than 4WD in the winter, as you don't get the back end sliding out on sharp turns near as badly. It is a real pain to remember to knock out the 4WD when approaching tight corners. (Yes, rally slides are fun, but they usually aren't appropriate when driving down public roads. Scares the other folks...) Quote Link to comment Share on other sites More sharing options...
Zefy Posted April 5, 2006 Author Share Posted April 5, 2006 robm Zefy, where the heck did you get one of those trannies in Canada? Did you import it? Do you have plans for it, or do you want to sell it to someone who could really use it? (Assuming the weather ever goes back to normal up here in Terrace...) actually i got it in Kamloops from a guy who is a stage rally driver... he was using an RX as his rally car... then he smoked a rock! it was sitting in his back yard and his son(i think) parted it out... he's a friend of a friend of mine and all i had to do was go pick the stuff up... went up there, gave him a case of beer as payment and took as much as i could... along with the tranny i got the engine, harness, ecu, steering column, front/rear supension(with brakes) and the LSD... all for a 20 dollar case of beer! i am going to use the trans in my 79 brat... along with an ej22... Quote Link to comment Share on other sites More sharing options...
fangster Posted April 5, 2006 Share Posted April 5, 2006 Call it what you want, it's a legacy "AWD" transmission with EA bell-housing. Some early non US legacy transmissions also had the diff lock and 1.2:1 low range. GD there is distinct physical differences between a Full Time 4WD Box and a Legacy AWD box. Having said that it is possible to put Legacy internals into an EA82 box. Where did you hear about a diff locked version of the Legacy? I have not seen or heard of one in Australia or NZ. We have always had the dual range version available in low ratio you mentioned. Quote Link to comment Share on other sites More sharing options...
GeneralDisorder Posted April 6, 2006 Share Posted April 6, 2006 Seen a pic of one here on the board once - may have been JDM. While there are certainly physical differences in outward appearance, the design, and even many of the internal parts are the same. Subaru has not fundamentally changed the 5 speed design since it appeared in 85. Full-Time-4WD is just the early marketing term for the same thing we have today. They changed the marketing term to AWD, but the concept and implementation remain unchanged. GD Quote Link to comment Share on other sites More sharing options...
fangster Posted April 6, 2006 Share Posted April 6, 2006 Seen a pic of one here on the board once - may have been JDM. While there are certainly physical differences in outward appearance, the design, and even many of the internal parts are the same. Subaru has not fundamentally changed the 5 speed design since it appeared in 85. Full-Time-4WD is just the early marketing term for the same thing we have today. They changed the marketing term to AWD, but the concept and implementation remain unchanged. GD Well I'll just agree to disagree. I've read of differences listed between AWD and Full Time 4WD but it's hardly worth fighting over Would be very interested to see that Legacy - tis the only problem I have with Legacys (or Libertys as they call them here) - the lack of centre lock. Quote Link to comment Share on other sites More sharing options...
TheSubaruJunkie Posted April 6, 2006 Share Posted April 6, 2006 The FT4WD and the AWD Tranny's should be identical. I'd be interested in hearing your point of view on the slight differences as I dont see how there could be any. Ive never seen a legacy with a diff lock switch... but i do know the STi's have one that is variable. -Brian Quote Link to comment Share on other sites More sharing options...
fangster Posted April 6, 2006 Share Posted April 6, 2006 Ive never seen a legacy with a diff lock switch That is one reason why there is a difference between the boxes. Here's a webpage I found quickly http://www.4x4abc.com/4WD101/difference_4WD_awd.html Yes it is being pedantic of me to say there is major differences. In the end its all the same essentially - just a lack of "diff lock switch" Quote Link to comment Share on other sites More sharing options...
Subaru Jim Maple Ridge Posted April 6, 2006 Share Posted April 6, 2006 Cool website. Too bad Subaru gets only passing mention. I would still like to see a detailed schematic of the RX tranny we are talking about, the dual range with the center diff lock. Quote Link to comment Share on other sites More sharing options...
WoodsWagon Posted April 6, 2006 Share Posted April 6, 2006 Legacy AWD trannies have a viscious limited slip differential in the middle, vs the Full-time 4wd having an either open or locked center diff. So they aren't just a rebadged system. Quote Link to comment Share on other sites More sharing options...
fangster Posted April 6, 2006 Share Posted April 6, 2006 I would still like to see a detailed schematic of the RX tranny we are talking about, the dual range with the center diff lock. Does this help Jim? (from a 1989 US FSM) Quote Link to comment Share on other sites More sharing options...
Anthenium Posted April 7, 2006 Share Posted April 7, 2006 Okay, could someone explain the difference between 4WD & AWD? Fat Tony - http://www.smashbandits.com Quote Link to comment Share on other sites More sharing options...
fangster Posted April 7, 2006 Share Posted April 7, 2006 Okay, could someone explain the difference between 4WD & AWD? http://www.answerbag.com/q_view.php/1411 If you have a normal EA82 box with a 2WD and 4WD position(s) - then this 4WD. Quote Link to comment Share on other sites More sharing options...
Subaru Jim Maple Ridge Posted April 8, 2006 Share Posted April 8, 2006 Okay, could someone explain the difference between 4WD & AWD? Fat Tony - www.smashbandits.com Check previous page, posting #19 by fangster, so specific that it confuses. Not sure how all of that info relates specifically to Subaru; this fellow is too knowledgeable in Jeep and other fixed axle animals. Further to the original thread, Zefy and I played with the toy this afternoon for a couple of hours, going as far as pulling the top covers from the RX tranny and a spare DR 5sp lying about. With the touted 'center diff lock' disengaged, spinning the input shaft with a clutch plate could turn the rear output shaft only, not a driveshaft, even if you held both front outputs. With the center diff engaged, the rear output did turn the shaft. Any power sent to the rear with diff disengaged would be minimal at best, neglible would be my choice word. Could it be that there are viscous friction dics? Are they subject to damage from abuse? As to previous mention, the electrical plugs are identical to all '85 and '86 DR trannies, and I don't even know what I did with the dist to check that connector. Will someone who knows PLEASE put this thread to rest? Quote Link to comment Share on other sites More sharing options...
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