Can loss of AWD be from the speed sensor on the tranny?

Flywheel, Clutch, Transmission, Axles, etc...

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ericem
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Can loss of AWD be from the speed sensor on the tranny?

Post by ericem »

Just wondering, im going to subaru, and there going to check it out, because i dont believe this transmission shop rebuilt the rear drive solenoid C, and clutch. But it sometime binds when i make a tight turn, so can it be that? If the clutches were worn silly, it should NOT bind a little right?


I am talking about this sensor if ur wondering, or is it not there on the 1st gen legacies 89-94?

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Manarius
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Post by Manarius »

VSS1 has NOTHING to do with AWD. Torquebind comes from solenoid C issues or worn out clutchpacks.
Manarius wrote:The Neo-Cons would call me a defeatist. I'd call me a realist. I'm realistically saying that a snowball has better chances in the blazes of hell than democracy has in Iraq.
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ericem
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Post by ericem »

Manarius wrote:VSS1 has NOTHING to do with AWD. Torquebind comes from solenoid C issues or worn out clutchpacks.
so there is no sensor?????? How will the computer know if its slipping, does it have a mind of its own?
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Post by Manarius »

VSS1 only runs the Speedometer. I don't know which sensor lets the TCU know of a speed difference.
Manarius wrote:The Neo-Cons would call me a defeatist. I'd call me a realist. I'm realistically saying that a snowball has better chances in the blazes of hell than democracy has in Iraq.
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ericem
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Post by ericem »

Manarius wrote:VSS1 only runs the Speedometer. I don't know which sensor lets the TCU know of a speed difference.
oh, well i checked my codes, and i got a previous code calling for speeed sensor 2.
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Post by Manarius »

ericem wrote:oh, well i checked my codes, and i got a previous code calling for speeed sensor 2.
Well, I think you should act on that then.
Manarius wrote:The Neo-Cons would call me a defeatist. I'd call me a realist. I'm realistically saying that a snowball has better chances in the blazes of hell than democracy has in Iraq.
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Post by Legacy777 »

Manarius wrote:VSS1 has NOTHING to do with AWD.
You are 100% incorrect.

The VSS1 tells the TCU how fast the rear driveshaft is spinning and is exactly how the TCU knows whether to apply more or less line pressure to the duty c solenoid.


ericem,

Both speed sensors need to be functioning properly for the AWD system to function correctly. It's possible the rear speed sensor, the clutch packs, or the duty c solenoid may need to be replaced, and could be causing the binding problems.
Josh

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Post by Manarius »

Legacy777 wrote:You are 100% incorrect.

The VSS1 tells the TCU how fast the rear driveshaft is spinning and is exactly how the TCU knows whether to apply more or less line pressure to the duty c solenoid.


ericem,

Both speed sensors need to be functioning properly for the AWD system to function correctly. It's possible the rear speed sensor, the clutch packs, or the duty c solenoid may need to be replaced, and could be causing the binding problems.
*puts on stupid cap* :smt086

VSS1 usually makes the speedo go broke....
Manarius wrote:The Neo-Cons would call me a defeatist. I'd call me a realist. I'm realistically saying that a snowball has better chances in the blazes of hell than democracy has in Iraq.
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Post by Legacy777 »

The speedo is VSS2

VSS1 "shouldn't" have any affect on the speedo. It should however through a code in the TCU.
Josh

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Post by ericem »

Legacy777 wrote:The speedo is VSS2

VSS1 "shouldn't" have any affect on the speedo. It should however through a code in the TCU.
hmm, well no existing code is being showed. Im going to subaru tommorow i believe, so they will look at the car, oil changes(diffs, and engine) then they will clarify what exactly the problem is. Thanks.
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ericem
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Post by ericem »

Im just wondering, if i unplug the tranmission connector, won't that tell me if the clutches are ok, because it should do 50/50 split? correct? Because no power will go to the solenoid.
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Post by Legacy777 »

Not really.....to just disconnect the duty c solenoid connector....you have to disassemble the transmission.

Plus with it removed, you're going to get torque bind real bad.....and if you don't get torque bind, I don't really know whether you can determine whether or not the issue is with the solenoid or clutches.
Josh

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Post by ericem »

Thats why im asking, becauase if no power is being fed to the solenoid, and it still doesn't engadge then that would narrow it down to the clutch correct? I won't damage anything unplugging the transmission just to see if the AWD will engadge right?
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Post by Legacy777 »

You are making the assumption the clutches are completely 100% gone, and would get 0% torque transfer. The likelihood of that is probably slim.

With full line pressure going to the clutch packs, you're bound to get some torque transfer.....even if the clutches are worn to the point of needing to be replaced.

I don't think the transmission will work with the main connector unplugged. These transmissions are pretty much all electronically controlled.
Josh

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ericem
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Post by ericem »

Legacy777 wrote:You are making the assumption the clutches are completely 100% gone, and would get 0% torque transfer. The likelihood of that is probably slim.

With full line pressure going to the clutch packs, you're bound to get some torque transfer.....even if the clutches are worn to the point of needing to be replaced.

I don't think the transmission will work with the main connector unplugged. These transmissions are pretty much all electronically controlled.
ok, did it,and when i back up, it binds, and its all wheel drive 100 percent, NO slippage.
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Post by Legacy777 »

Ok.....so what are deducing from that?
Josh

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Post by ericem »

Well, subaru did all the tests, not issues, sensors everything checked out fine. Then it looked like when i was watching the guy, he changed the wiring harness, the short harness plugged into the tranmission, to the other plug. And now the AWD works :) but there is a delay, but it engadges silk smooth, and holds it hard. Its like if i floor it 1-3seconds delay, on normal accel and slipping it does it instantly, i saw from outside when my dad was driving.

Subaru suggested, that i go back the transmission shop, with a write up subaru gave me, that indicates what was checked, and what seems to be the casue. They say, becasue the transfer clutch was replaced, they may have not shimmed it correctly, so the fluid gets trapped? something like that, then he said there is a very tiny screen filter above the solenoid or around it and it can get dirt in, he said, it usually doesn't need replacing. But i wasn't really listening, the STi's got me :D . But my dad heard him. Anyway does that make sense? the transfer clutch may have not been shimmed? and there is fluid being trapped, then he said something about a pressure gauge. Im so happy :D
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Post by Legacy777 »

Well.....if Subaru said that, and it sounds like they were testing things ok....then it'd be worth having the trans shop check it out.
Josh

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Post by ericem »

The more i drive it the faster it engadges awd. Is it possible when they plugged in there computer they reprogrammed the TCU, which is why it works now? Before i could sit theere all day and no AWD. Should i do a oil change for the tranny? Not a flush, just oil change? And does anyone recommend a higher dextron level, or just stick to III? thanks.
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Post by Legacy777 »

I don't think they reprogrammed it....I'm unaware of any reprogramming for the first gen legacies.

As for an oil change.....you could try it. Just stick with DextronIII.
Josh

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Post by ericem »

Ok, thanks.
1993 Subaru Legacy L AWD Wagon R.I.P
1994 Subaru Legacy SS R.I.P :(
2004 Nissan Titan LE 4X4
2007 Subaru Legacy GT :)
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