27 replies to this topic

[grant]

I have a 2002 Outback Sport that I want to weld or lock the center differentail. Its an AWD right now. It has the 4 speed automatic transmission.

Is there some sort of center dif lock already present on these transmissions? Is this easily done? Or does the entire transmission have to come apart first?

Basically I want to use the rear output of this engine to drive a transfer case. The front half shaft outputs won't be used anymore.

[torxxx]

IIRC they do have a center diff, but its a clutch pack so there wont be any welding...
I could be wrong, but last time I saw one torn apart, I saw clutch plates due to the AWD. The 2002 is new enough that its a electronically controlled AWD system (constantly changing power front to rear)

[grant]

No chance of bolting the clutch plates or changing the bias between them to make it as good as locked?

How deep in there is it? Can I get to it from the oil pan?

Does anyone know where to get subaru engine to toyota/suzuki transmission adaptors?

I have this 2002 outback and the poor thing only has 32k on it, but it will never be a "car" due to front end dammage.

Thanks.

[torxxx]

grant, crap I didnt even see you are in alaska. what part?

Ok knowing its automatic, it is clutch plates that run the RWD part of the AWD. You can get to it with the tranny in the car, just have to unbolt the Y pipe and engine mounts and jack the front of the engine up. I've rebuilt the clutch discs in the car before. its just messy because you'll have ATF dripping out of the tranny.

[Andyjo]

just put a switch inline w/ the duty C solenoid wire, you can lock up your clutch pack that way
Dunno if it works for 02'.. but it worked for my 4eat
http://www.ultimates...ead.php?t=50264

[torxxx]

Austin did you find any adverse effects of running the AWD that way? it doesn't throw the TCU off or change the shift patterns? The 4EAT seems to be a pretty weak transmission from all the swaps I've done at work.

[grant]

Well, in my application I would like to run a transfer case off of the rear output. You guys don't think it will hold up?

Since you've taken the clutch pack apart and rebuilt it, any good ideas on how to fuse them together? Bolting or changing the spring locations?

I'm in Anchorage. Last time I had a subary annoy me it turned into a trailer.

[torxxx]

running a T-case would lower the gearing, so it should work.

[Andyjo]

running a T-case would lower the gearing, so it should work.

Might also start busting halfshafts.
and you'll need some more height to get a t-case in there.

[grant]

Since the front body is trashed I was thinking about some 35s on toyota axles.

Where do most people have a problem when using an AWD or 4wd transmission in RWD mode only? Is this really a concern when done properly or is it just a bunch of bad feelings?

[Andyjo]

i'd just say screw it to the awd system.. and get a real tranny on there, that can handle the abuse...

[TheSubaruJunkie]

Use an older 5speed AWD tranny with an open center diff... then you can just weld that.

-Brian

[sayn3ver]

welding fixes everything.

like he said, you can covert almost all of the ej series trannies to RWD. You can either weld the center diff or MRT has a spool which can be installed which makes the tranny rwd.

[Mike W]

If the 2002 has a rear extension housing like the mid-90's 4EAT, then it seems to me that you should be able to remove the rear housing and either weld the plates together or machine something solid to replace the clutchpack. I've only removed and replaced extension housings but the guts in there really aren't all that complex so it seems feasible to me. There are detailed pics around here somewhere of that extension housing, probably in threads pertaining to "torque bind." Once you get the exhaust etc out of the way the tail housing come off pretty easy if you want to check it out for yourself. The paper gasket will probably tear but they're only a couple bucks from Subaru.

Grant, do you still have pics of your other Subaru projects? I remember seeing your trailers etc a couple years ago and gotta say you're sick and I'm looking forward to whatever you do to this car.

[nipper]

Since the front body is trashed I was thinking about some 35s on toyota axles.

Where do most people have a problem when using an AWD or 4wd transmission in RWD mode only? Is this really a concern when done properly or is it just a bunch of bad feelings?

i'm not sure what your asking.
The automatice do not have a center differnential. They have a clutchpack, and a solenoid that controls it. Since the clutch pack is designed to allow some slip for differntial action, there isnt much you can do get what you want. If you install the switch, you will still manage to chew up your clutches pretty badly. This can give you perm awd or no rear wheel drive at all.
There really is no way of getting what you want unless you open up the tranny and weld the clucth plates. If the computer is working, i would leave iit be, as the automatic awd system is very responsive.
These are fwd biased cars, and they will not operate well in rwd only mode, thats if you can even get it to behave that way.
If you were to remove the front axles, the copmouter will disnegage the rear drive at 50 mph. The manual the viscous coupling will over heat and give you what you want.
Now since this is a junk heap and i am assuming is never going to go on the road you can underinflate one tire and drive it and let the plates fuse themselves.
In a normal subaru, you have no choice, even in the older d/r to pick just rwd. These are fwd cars. The dual range will however drive just the rear wheels since there is no center differential action at all.
If the vehical is normally rear wheel drive with a 4wd system, then the rear wheels are the predominat drive wheels. No one has a problem with it, its just the way the drive system and the suspension was designed.
Fwd pulls rear wheel drive pushes. RWD is best suited for pulling loads or trailers, AWD is the best of both wrolds, and FWD gives a better traansfer of pwoer to the drive wheels (same for a rear engine rwd car) Also the drive wheels get better traction.

hope this helps.

nipper

[Hodaka Rider]

Good summary, Nipper, but he wants full output to the rear to drive a divorced transfer case. I know that this has been done with an earlier auto (EJ/auto/transfer case in a hatch). The spool might be the best way to go if you want to keep the auto, but you may be on your own for making one (is the spool available for the auto? anyone?)

[Mike W]

I did a little search and came up with some pics of that rear extension housing. Here's an index to a bunch of trany disassembly pics and this shot here shows the clutch pack stuff. The clutchpack is the darker colored spliny thing on the left. What I was talking about is carefully welding the clutchpack or possibly replacing the clutchpack with a machined (and heat treated?) part that would basically act like a spool. Seems do-able but I wonder because if it was that easy, wouldn't Mudrat have welded his when they did the Rubicon? Instead he kept the clutchpack and locked it up via the solinoid.


If you take that rear housing off, be warned that there's a pin and spring etc that want to pop out and putting it back can be a little tricky the first time.

[grant]

Great pictures! More than I could have hoped for!

From what I've seen in a few pictures I can't understand why it would be weak at all. In fact, I'm surprised to see such a small pinion in such a high performance car.

This is the FWD pinion:


This is the FWD pinion as a whole:



Here is the back side of the transmission:



It looks like FWD pinion is gear driven off of the same shaft that drives the RWD clutch. So the full torque of the transmission passes through the upper gear which drives the RWD clutch.

If a good RWD clutch elimination solution were found I don't see what the problems would be with strenth.

[LosDiosDeVerde86]

just put a switch inline w/ the duty C solenoid wire, you can lock up your clutch pack that way
Dunno if it works for 02'.. but it worked for my 4eat
http://www.ultimates...ead.php?t=50264

i knew you'd chime in. i think that the differences in the AWD system wouldn't allow the Andyjo modification to work.


could be right, could be wrong....what do i know.

[grant]

What are the differences between the transmissions which allow the solenoid modification and the transmission in the 2002 outback?

[LosDiosDeVerde86]

What are the differences between the transmissions which allow the solenoid modification and the transmission in the 2002 outback?

i don't think that it's a difference in transmission that matters, because i think they're pretty much the same. however i think it's differences in the way the the awd is activated

[grant]

One of them does not use a solenoid?

[LosDiosDeVerde86]

One of them does not use a solenoid?

i'm really not sure about the 02s. sorry.

[nipper]

i'm really not sure about the 02s. sorry.

they all use a solenoid, going back to the first awd system, that plus a spool valve insdie the transmission.

nipper

[Andyjo]

The autos use a clutch pack, the manuals use a viscous center diff... what's so hard about that?
some guy made his impreza RWD... i think i saw that on nabisco... welded the plates & stuff together in there... not that hard i guess, but could be a pain..