99 Legacy differential issues

[Wombat3]

So, I'm just gonna post what I've got going on and what I've found and hopefully people can chime in who know more about this than me. Even if you don't know about all parts of my question please post what parts you do know.  I've read alot of posts on this forum and other Subaru forums but this is by far the most involved repair I have attempted.

 

Short version: Duty C solenoid.  Most info posted in this thread should apply to 99-04 models as this repair is similar on those years (99 models with TZ1A2 trans)

 

Last fall my AT Temp light started flashing intermittently, with torque bind when it was flashing.  After a couple weeks it pretty much stayed on.  I found how to get the TCU codes and got codes 93, 27 and 79.

According to this post: http://www.ultimatesubaru.org/forum/topic/113278-how-to-read-transmission-codes/?do=findComment&comment=1103000

27 ATF temperature sensor. Detects open or shorted input signal circuit.

79 Transfer duty solenoid. Detects open or shorted output signal circuit.

93 Rear vehicle speed sensor. Detects open or shorted input signal circuit.

I thought that it had to be a loose TCU cable or something because how could all 3 go bad?  I checked the codes a few times over a month or so and got the same codes, clearing them in between at least a couple of those.  A while later I was able to try unplugging and reconnecting the main cable at the TCU, Transmission, and the weird little extension above the transmission.  Light still on, still torque bind.  I was originally writing this post to ask for help verifying the Duty C solenoid, but just last week as I was finally going into detail researching the problem and the repair I decided to check the codes again, and with a few checks over the past week or so it's showing only code 79 which seems to verify that as the specific problem.

 

Now that you've spent a couple minutes reading my description of the problem, here are my actual questions:

 

1. I have a vibration sometimes, starting at about 60 MPH.  Sometimes it is in the steering wheel, sometimes more the whole car, and it varies greatly in strength on different days at the same speed.  Sometimes pressing on the brakes hard will make the vibration stop for a while, sometimes not.  Does this make any sense to perhaps be caused by the transfer solenoid?

 

2. Until I have time and money to actually replace the transfer solenoid, can I safely disconnect the front differential solenoid and will that reduce the torque bind when parking?

 

3. Has anyone else done this on a 99 phase 2 transmission, TZ1A2 who can verify the part numbers I found?

31942AA103 - transfer solenoid

31337AA191 - case gasket

31952AA060 - Transfer valve gasket plate

31523AA410 - transfer clutch pack

31954AA071 - transfer valve gasket gasket

 

4. I swear I had some other question which I will probably remember on the way to work tomorrow lol

 

Thanks for taking the time to read my long post.

I attached the Vin Plate or whatever it's called as well

 

[john in KY]

Your vibration comments got me to thinking you probably have the driveshaft failing along with your other problems. When it fails it likes to take out the back of the transmission along the way. 

[johnceggleston]

 

27 ATF temperature sensor. Detects open or shorted input signal circuit.

79 Transfer duty solenoid. Detects open or shorted output signal circuit.

93 Rear vehicle speed sensor. Detects open or shorted input signal circuit.

 

this is a wiring problem. in my opinion.

do you have a dented trans oil pan?

do you have mice or rodents chewing on wires?

 

i would trace the wire runs from end to end.

maybe check thr large connectors on the rear passenger side of the engine first.

look for dirt, corrosion, bent pins, or loose connections. 

 

it maybe could be the TCU,

but i would check it last.

they don't fail often.

Edited April 3, 2016 by johnceggleston

[1 Lucky Texan]

if you use the FWD fuse, does the shaking at 60 mph symtpom change? or is that system still broken.

 

swapping tires front to back affect it? any cupping or other uneven wear on the tires?

 

original struts I guess? they are likely bad.

 

test for loose inner tie rods. inspect brakes for uneven pad wear, clacked caliper brackets/bolts, sticking caliper....check ,in pairs, that no brake/hub is hotter than its mate after a highway run. Worn rack bushing might also be in this mix.

 

Does the shaking happen often enough that you could - SAFELY - have a nother car pace you. Set up a signal with the emergency flasher, or have a passenger use a cellphone to let the other car know when the vibration is present - maybe they could spot a wheel bouncing shaking or ???

Edited April 3, 2016 by 1 Lucky Texan

[Wombat3]

Your vibration comments got me to thinking you probably have the driveshaft failing along with your other problems. When it fails it likes to take out the back of the transmission along the way. 

Is there a way to examine the driveshaft to check for this?  I'm ok with taking the exhaust and heat shield down to do this if needed.

[Wombat3]

this is a wiring problem. in my opinion.

do you have a dented trans oil pan?

do you have mice or rodents chewing on wires?

 

i would trace the wire runs from end to end.

maybe check thr large connectors on the rear passenger side of the engine first.

look for dirt, corrosion, bent pins, or loose connections. 

 

it maybe could be the TCU,

but i would check it last.

they don't fail often.

No dent in the pan, no mice that I've seen or messed up wires that I have seen.

I didn't trace over the entire length of the wire harness yet, but I did previously unplug and reconnect the connections at the TCU, transmission, and extension cable.

At some point since I got those 3 codes all except 79 have stopped showing.

[wtdash]

BUmp for FWD Fuse. Either in fuse box by battery or still by pass. strut tower under hood.

 

 

 

 

 

Tangent...interesting the EJ221 - I thought they were EJ222.

 

 

 

Edited April 3, 2016 by wtdash