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RX dual range awd are they just for the streets?


mikaleda
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okay i am going to turn my 80 into my new off road rig. I'm planning on doing a five lug swap and upgrading the ea71 up to an ea81 and i want to upgrade to a dual range transmission. I just happen to have a neighbor that has an 87 RX with the dual range AWD center diff lock and i can get it for dirt cheap. what i am wondering is are these transmissions tough enough to stand up to bigger tires and offroading? would i be better off just getting an old dual range transmission? just for reference i am planning on running 205 75 r15

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The RX D/R is  perfectly capable of going to larger tires.It is Just as robust as the D/R's.BUT, has higher Low range gears.

The Regular ol' D/R is 1.59 low.The RX is 1.19low.

Withe rarity of these transmissions, I would not beat it.BUT, know folks who have.And it was fine.

Lower gears help more than wheel speed.

And considering we havta use wheel speed anyway, lower gears are preferred.

Let me say that again.Lower gears are preferred.You will grow to hate this statement through your offroad Subaru journey.(because we are limited)

 

You can rock it if it is your only option.But honestly the D/R is still fairly prolific.

And those tires are not very big. LOL

cheers

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The RX has a 1.19 Lo range but 3.7 diff ratio.A better choice would the the low range box from any of the other non turbo  EA82 subarus.

 

Also why are you swapping the 5 lug stuff? it has less travel than the stuff that is on there now.If its a wheel fitment issue then anything running 6 lug will bolt on either by drilling the wheels or the hubs.The wheels from a 4x4 chevy,or most any japanese mini truck have that bolt pattern.

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Cool thanks for the info, and yes I already knew I wanted low gearing. As for the reason for the five lug swap I just found out that it has a bent unibody, and I know my front end is never going to sit right again so I want the adjustable caster camber. Believe me I really don't want to, I just put Kyb gr2's in :(

As for the small tires I was thinking of going 235 75 r15 but I was thinking about the Rx trans being higher geared. Now that I know the ratios on the low end I'm going to get a regular dual range.

I am planning on mudding with it mostly and maybe some climbing, I'd love to put a set of 235 75 r15 wild country's on it.

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are they just for the streets? No  The Dual range RX trans would work awesome in a gravel/tarmac rally setup.  I'd love to have the higher low range for rallying, since the low on a regular D/R is TOO low for use as a rally tranny.

 

Problem with the trannys is they don't hold up to very much power.  I was thinking about putting my EG33 into one of my lifted rigs but I was told that anything over ~150 hp driven semi hard will destroy the trannys.  Hell 165 hp destroyed reverse in my outback 5MT, but I think that was due to 100% strictly design flaw (reverse lockout walking too far forward)

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Uberoo what part of the five lug stuff has less travel the stuts or axles? hadn't heard that before so good to know.

 

 

if you get a chance go to your local PnP and flex the suspension on various subarus. The rear ej suspension is horrible because it binds up after a couple inches or so because the pivot points of the control arms are not in line or in sync.By contrast the rear EA suspension will smoothly travel because the control arm pivot points act along the same angle.

 

Front struts are pretty much the same except there is a little less travel in the the EJ stuff,But the EA suspension has a radius rod to control the lower control arm.Its pivot point does not act along the same line of action or angle as the control arm so it introduces binding.So EA and EJ front suspension is more or less a wash.In either case the struts limit travel,then the axles will limit travel before any binding from the suspension come into play.

 

Like I said visit a PnP and play with suspension parts.You might have to remove some things to find out where stuff is limiting travel.On a legacy even with the rear strut removed and out of the car their is very little flex due to the inherent binding issues..

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The rear suspension isn't going to change much on mine since I am only going to change the backing plate, rotor and caliper. I'm not really sure if I am going to do the five lug swap or not, I would rather do a rear disc conversion and a six lug redrill. Unfortunately I'm not sure if I can straighten the body out enough to make the tire sit right, I'm going to try. Does anyone got ideas of how one might reinforce the unibody on one of these old gen subies?

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Link to my build thread in my signature, page four has the pics of the rust (i'm still working on getting pics of the bottom.) I crawled underneath it yesterday since the sun was out :grin: and I think that it looked worse than it was. The molded frame is definatly bent and my floor boards are definatly sagging but, I think the body itself is straight. I'm thinking about just straightening out the floor boards and replacing the steering rack and see what happens. If everything is straight and my tire isn't wearing weird any more then I'll just buy a set of Peugeot 14's.

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How's the rust on the RX? You might be time/effort ahead to just use that body instead of your wagon.

 

The Full time 4x4 box will need to have the center diff locked the whole time you're offroad so it will need the vacuum hoses and solenoids hooked up. The low range is not very good, it's a 1.2:1 reduction instead of a 1.59. Plus the differential gearing is only 3.7 instead of 3.9, so it's less gear reduction there too. You will also have to swap in the RX rear diff to match, but you will want to score that RX rear diff anyways because it's likely a LSD which is worth $300 to the Datusn 510 crowd if you don't use it.

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Thanks for the info woods wagon, I have a deal going with the owner we might be parting it out or selling the whole car. I don't want 1.19 for low range so I will be using a regular old dual range maybe a five speed if I can find one :grin: I'd really love to find a 4.11 trans and rear end but, wish in one hand you know what in the other and see which one fills up faster

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If you get the car, I'd be interested in the side skirts, and rear under bumper lip.

Okay I'll keep that in mind, bratman 18 has first dibs on side skirts and rear bumper lip. Now I'd better write that down otherwise ill end up forgetting :P lol.

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