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06 OBW 2.5, 05 Forester, had 03 H6 OBW
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Discussion Starter #1
96,000 mile used trans, from a 2004 LL Bean H6.

Got it bolted in, trans is filled to the mark on the stick, on the jackstands the rear wheels do spin in all gears.

Took it for a test run, by chance it was snowing.

1, 2, 3, D, the rear wheels do not drive until I get the revs up to about 3000 with the fronts spinning, then the AWD kicks in, and there is a bit of a groaning while it operates. Revs drop below 2500 or so and then it's just the fronts again.

This wouldn't seem to be a grooved clutch basket, or any other post-torque-bind symptom, based on what I have read for the past few years.

Any thoughts?

Is the duty-c external? In the pan? in the rear case?
 

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2009 Tribeca Now - 2004 Outback EJ259 - Sold
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1,069 Posts
Could be:
-weak transfer solenoid that won't engage properly until it receives a DC above 40-50%.
-MPC material has worn down too much or is gone all together, requiring too much movement to engage or metal on metal plates
-sticking transfer clutch valve

The only way to find out for sure whats happening is to dig into it and have a look.
Good news is you can do it with the transmission still in the vehicle.
http://opposedforces.com/parts/legacy/us_b12/type_28/automatic_transmission/at_transfer_and_extension/illustration_1/
Pull the extension housing off the back & the transfer solenoid should be right in front of the assembly you pull out.
http://opposedforces.com/parts/legacy/us_b12/type_28/automatic_transmission/at_transfer_and_extension/illustration_3/
 

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My first thought was line pressure, but if it otherwise seems to run and shift properly (albeit with the front wheels only) in normal driving, low line pressure isn't likely.

Some measurements might help isolate the issue, if you are able to do them; here I'm thinking: duty cycle signal to the AWD solenoid and AWD clutch hydraulic pressure. The first would confirm whether or not the TCM AWD electronic control system is working, and the pressure test would indicate if the AWD solenoid and transfer valve are responding to the TCM commands.

There's always the possibility that the AWD clutch plates are worn out.

But, double check that the rear drive train (drive shaft, rear differential, rear axles) is intact and properly engaged. For example, a rear axle that isn't fully inserted into the differential could give those symptoms.

The duty C (AWD solenoid) on that tranny should be in the rear extension case.
 

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06 OBW 2.5, 05 Forester, had 03 H6 OBW
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Discussion Starter #4
Everything other than the trans guts is exactly as before the trans swap, and my 200,000 mile transfer clutch worked perfectly.
 

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Everything other than the trans guts is exactly as before the trans swap, and my 200,000 mile transfer clutch worked perfectly.
Not sure I understand what parts of the AWD system are from your original transmission and which came with and were retained with the "new" one. Did you move just the clutch from the "old" to the "new" or the complete extension section?

If you're using the "new" transmission's extension case, then the solenoid/transfer valve and transfer pipe that are mounted in the extension housing could be malfunctioning.

In addition to ntippet's links, see http://www.subaruoutback.org/forums...on-rebuild-without-removing-transmission.html. There's good photos of the clutch, as well as the solenoid and transfer pipe area.
 

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2009 Tribeca Now - 2004 Outback EJ259 - Sold
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Yeah I didn't quite understand what you were saying either CNY, thought you had swapped over a completely "new" tranny.
 

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06 OBW 2.5, 05 Forester, had 03 H6 OBW
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Discussion Starter #8
The road test was at 1:30 AM at the end of a full day of wrenching, then I was up a little before 8 to get ready for work, it's a wonder I'm coherent at all.
 

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2009 Tribeca Now - 2004 Outback EJ259 - Sold
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If you have FreeSSM running, there is something else you can try real quick.
 

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06 OBW 2.5, 05 Forester, had 03 H6 OBW
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Discussion Starter #10
Don't even know what that is... I'm going to see if it has trans codes on my way home tonight.
 

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2009 Tribeca Now - 2004 Outback EJ259 - Sold
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Alright well its in my signature if you are interested.
The program has some additional capabilities that may be useful in diagnosing whats going on with the transfer solenoid.

What are you using for your scanner?
 

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06 OBW 2.5, 05 Forester, had 03 H6 OBW
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Discussion Starter #12
At temp light not flashing but pulled a code 93, rear vss.
I think that's good news
 

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06 OBW 2.5, 05 Forester, had 03 H6 OBW
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Discussion Starter #13
Just looked in the service manual- you have to replace the entire harness, drop the driveshaft, drop the pan, pull all the connectors from inside the pan, drop the full exhaust to replace the VSS?

Can't imagine what that costs, since there are other sensors on the same harness.

I assume people just cut and splice the wire when they have a spare VSS from another trans, as I do.

It's not some messed-up impossible-to-splice wire, is it?
 

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06 OBW 2.5, 05 Forester, had 03 H6 OBW
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Discussion Starter #14
Looking at my old trans, it's 2 wires plus a shield, easiest place to splice will be all the way at the top, assuming I can finagle enough room to cut (always room for that!) and solder.

I'm hoping there is space to access the sensor without dropping the exhaust.
 

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Dave:

The FSM has a "troubleshooting tree" regarding code 93. The steps focus initially on checking continuity of the wiring, and the resistance measured between the two wires of the rear VSS. Have you made these checks? Might be worth doing before trying to splice a coaxial (shielded) cable. (In the FSM version I have, the section starts around page AT-124.)
 

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06 OBW 2.5, 05 Forester, had 03 H6 OBW
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Discussion Starter #16
Oh, believe me I'm measuring and looking it all over before I start hacking things up, I just want to be prepared for the 'worst case scenario'.

I have located and measured the impedance on the connector pins on my old trans so I can get right to it Wednesday, when I'll have a chance to look at it.

I figure it's the sensor, the wires, or a pin got mangled in the connector (hard as that last one would seem to be to accomplish).

If I do splice it (best thing is to tease the pins out of both connectors and do no splicing, not sure this is realistic) I will do it all the way at the top, after the shield wire is terminated and it's back to just 2 exposed wires.
 
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