AWD Binding

[TomsSVX]

Yeah... turning up a code 24 out of the teal. I tried plugging in the FWD fuse and to no avail. Nothing happens?? Got a feeling it has to do with the chasis rather than the trans because I rebuilt the transfer clutches and solenoid C with parts known to be good but not new parts. This car has been having trouble with binding since before I got it. people like to just remove the rear half of driveshafts in order to "fix" their problems Anyway, anyone have any ideas on where I should start looking before I go and buy a new solenoid C and tear the trans apart again??

Tom

[Tim]

My old tranny is cursed I tell ya! J/k


Bump for good luck

[TomsSVX]

well at least the AWD is working Did u ever try to FWD fuse in ur car to see if it would do anything?? Just curios as to whether I am tracing wires in the car or the tranny??

Tom

[oab_au]

As it posts a code, it would have to be a wiring problem back to the C solenoid, the Solenoid itself, or the TCU.

If it was just the clutch plates binding it would not post the code.

Can't think of any thing else Tom.
Harvey.

[Tim]

Yea in my car once I put the FWD fuse in all the problems cease. This is the list of problems I had on my old tranny before my awd gave up completely:

1.Binding
2.A thunk/clunk when I came to a complete stop for like 10 seconds. It felt like I shifted into park when cold and shifted into drive.
3.a light thunk when gassing it, that's how I knew the rear engaged.

[Manarius]

Tom, are you binding on sharp/slow corners? This would make me lean much more towards the center diff. Over time, the 4EAT's will start to torquebind, and the source of this binding is the center diff (hence why when you put in the AWD fuse, nothing changes because the center diff is still powering the front wheels).

If you let this go, eventually you'll shear all the teeth from your center diff and you'll have a car that won't move.

[TomsSVX]

I will not drive the car like this. I still have my silver to drive, just trying to get my daily driver working. I know it has to do with the transfer clutches in the center diff, just trying to figure out what exactly is going on. I would just go buy a SOl. C and be done with it but the fact that my FWD fuse doesn't work makes me lean toward a different problem. I was wondering if anyone has had the same thing happen to them?

Tom

[intelisevil]

Try a bottle of limited slip differental additive in the transmission.

http://www.subaru-svx.net/forum/showthread.php?t=1980

It seems to have worked for me, no more binding in slow turns, transmission seems to shift the same as before. Now if I put the tranny in neutral when I'm just barely moving (foot off of brake) the car will actually continue to roll some. Prior to using the additive, the binding was bad enough that under the same conditions, the car would stop almost immediately . . . in neutral!

Previously, when I put the FWD fuse in, nothing happened, the light on the dashboard didn't even light up. I'll have to try it again, obviously just for short term testing . . . I've read what the long term results can be.

Still throwing a code 24, but this gives me more time to search for a WRX 5-speed etc.

Dan

[TomsSVX]

this is not my clutches sticking, it is the solenoid allowing full ATF pressure to the clutches. Once I can figure out why Sol. C is not working I have solved my problems. like I said, I don't "need" this car right now so I am not going to try temporary solutions, I just want it to work right

Tom

[Earthworm]

Do you have a spare TCU? That was Randy's problem a long time ago.

[TomsSVX]

I know I have a couple.... just need to find them.

Tom

Originally Posted by Manarius

Tom, are you binding on sharp/slow corners? This would make me lean much more towards the center diff. Over time, the 4EAT's will start to torquebind, and the source of this binding is the center diff (hence why when you put in the AWD fuse, nothing changes because the center diff is still powering the front wheels).

If you let this go, eventually you'll shear all the teeth from your center diff and you'll have a car that won't move.

How exactly do you shear teeth off of something that doesn't have teeth? The front and rear are connected through clutches, not gears.

Anyway, as was said, and you noted, it sounds like wiring. Probe some pins for resistance and voltage, an FSM would help greatly. Or just start throwing parts at it

[Trevor]

Originally Posted by TomsSVX

this is not my clutches sticking, it is the solenoid allowing full ATF pressure to the clutches. Once I can figure out why Sol. C is not working I have solved my problems. like I said, I don't "need" this car right now so I am not going to try temporary solutions, I just want it to work right

Tom

I am working from a Japanese manual showing the diff. type set up, but it would appear that the control arrangements are the same; i.e.fitting the fuse will fully activate solenoid C and the result is transmission locked front/rear. Therefore it would appear that your problem may be that, the solenoid is being continually energised (Specified as between 8 and14 volts) or is mechanically siezed open.

With the fuse in place, ignition on, engine stopped, selector in D and accelerator pedal fully released there should be 8 - 14 volts applied to the solenoid.

With the fuse out, Accelerator pedal fully depressed, then all as before, there should be no more than 0.5 volts.

Solenoid resistnce shoud be 9 - 15 ohms disconnected from the TCU.

Measuremants can be made at the TYCU between terminal - 3, (16 pin B68 connector) and ground.

I hope this information may enable you to ascertain if the TCU, solenoid or connecting wiring is electrically at fault, or the solenoid is mechanically faulty.

[Manarius]

Originally Posted by THAWA

How exactly do you shear teeth off of something that doesn't have teeth? The front and rear are connected through clutches, not gears.

Anyway, as was said, and you noted, it sounds like wiring. Probe some pins for resistance and voltage, an FSM would help greatly. Or just start throwing parts at it

Oh come on Thawa, you know as well as I do that when the AWD binds, 9 times out of 10 it's torquebind. Don't get smart with me. Torquebind isn't clutches sticking.

Originally Posted by TorqueBind

In the rear of the transmission is a watermelon sized aluminum housing that contains several valves, bushings and seals. The rear driveshaft that couples with the rear differential. The problem occurs in here, and the replacement of this cures it.

Inside of the housing the rear shaft spins and has teflon bushings and fluid seals for the AWD system. This is where much of the rear power is transferred. The problem occurs when these bushings wear against the aluminum. For some reason Subaru, or the transmission manufacturers, decided not to have a bearing or liner in lieu of using the housing itself as the wear surface.

This is where the problem and solution lies.

The bushings and seals wear the aluminum down after time. This allows the pressurized ATF to leak from one chamber to the next. The torque meant to be transferred to the rear ends up being greatly reduced and the fluid transaction causes the shuddering.

Source: http://legacycentral.org/library/torquebind.htm

It's throwing a code, this is an electrical fault. There are no teeth that transfer power front to rear.