All-Wheel Drive Legacy issue

[Lucenut]

Hi all, I'm new here. I have a nice 98 Legacy L wagon with ~ 150K on it. (Owned by my super-meticulous father the first 4 years). I work from home and it's our second car so it's only seen ~ 4K miles the past year. Somewhere in the past year it started feeling like the AWD was "locked-in" or something all the time. When turning sharp, backing out of the driveway you feel the tires chirping sorta (like in the old 4WD trucks I'd had when locked into 4-low).

 

I have an idea that maybe some switch or something is stuck that's supposed to delegate front/all wheel drive. Is that right? Should the car be FWD normally and AWD when necessary? Does anyone know if I'm guessing right and there's a sensor/switch that could stick and leave it in AWD all the time?

 

If not any other suggestions? The few times I have driven it more than 3 miles on the highway I swear there was some vibration or something I thought maybe in the tires/tranny. But I had tires, alignment, shafts, brakes, and struts all done and it still sorta has it occasionally. I'm guessing it was the AWD on the highway causing some noise/vibration. (very slight. A couple times I stopped at the mechanic and took him for a ride it wasn't noticable)

 

I'm thinking of putting a lift on it and maybe some fun paint job like camo and keep it as a fun car.

 

Thanks,

Greg:banana:

[frag]

You're in the right place to get help, but people will want to know if it's manual or auto.

[Lucenut]

Ah, it's automatic.

 

You're in the right place to get help, but people will want to know if it's manual or auto.

[frag]

Waiting for the gurus to show up, I can already tell you one thing. Under the hood, near the firewall I think, is a fuse holder marked «two wheel drive" or «front wheel drive». If you put a fuse in there (I guess 20 amp shoud do) Your car will be front wheel drive. If it's a problem with the AWD it will subside. If everything stays the same, then it's something else.

[JT95]

Should the car be FWD normally and AWD when necessary? Does anyone know if I'm guessing right and there's a sensor/switch that could stick and leave it in AWD all the time?

 

Your Subaru is AWD all the time. I may be mistaken, but I'm pretty sure that yours puts 90% of the power to the front wheels and 10% to the rear all the time, under normal driving conditions. (5 speeds put a little more to the rear.) Honda has what they call "Real Time 4WD" in which theirs is 100% front wheel drive until the car experiences a traction loss to the front wheels, at which point the rear engages. Subaru is AWD all the time. However, it will redistribute power away from a non-traction wheel to a different one. I was driving on an ice-covered interstate a couple years ago and could feel the power transfer taking place...it was a weird/cool sensation.

[porcupine73]

Hi and welcome!

 

When you had the tires replaced, did you get all four new tires, or just two new on the front or rear?

 

It sounds like your soob has what is often called 'torque bind'. Do you notice the AT temp light flashing at all on startup?

 

My typical torque bind spiel

1. For auto trans, if the AT temp light flashes 16 times on startup, then the TCU has detected some issue. Read the code(s); it may be a failed duty c solenoid (which can cause the binding).
    
   
2. All tires should be same brand and nominal size and tire pressure should be correct.
    
   
3. Measure the circumference of all four tires (wheel will have to be lifted off the ground to do it). They must all match within 1/4" circumference. You will not be able to visually see this much difference so the tire circumferences must be measured.

For automatic transmission:

1. For auto trans, flush ATF using a new quality fluid. Sometimes if the torque bind isn't too bad or just started, fresh ATF can help. Sometimes it takes multiple flushes over a period of time.
    
   
2. For auto trans, this one is a little controversial, but many people do it with success: put in a few ounces of differential limited slip additive (NOT gear oil - just the limited slip additive). If this helps, people often say they have to add a few ounces periodically. This was mentioned in an early 90's issue of Subaru TIPS newsletter.
    
   
3. For auto trans, you can try installing the FWD (front wheel drive) fuse to see if it makes any difference.
    
   
4. If the above did not help, then you may need to have the AWD transfer clutch replaced or at least serviced.

For manual transmission of that era, there isn't much that can be done short of replacing the AWD viscous coupling in the gearbox.

 

Other torque bind causes: improper towing (i.e. only two wheels off the ground on a dolly), running on a soft/flat tire for a period of time, getting a flat tire and replacing just that one tire while the others are worn, replacing just the front or rear tires, etc.

[Lucenut]

Wow, thanks for all the info. I had all 4 tires new Goodyears. I'll measure the circumference to be sure though.

 

I just tried it and you are correct, the AT Temp Light flashes 16 times on startup. Is there an online reference to see what the 16 flashes code means?

 

I'll try the 2WD fuse also and see what it does. Realistically I guess a guy could just run in 2WD here on the roads in FL. But I still want to troubleshoot the AWD so I have it if necessary. I'll measure the tires this weekend.

 

Thanks,

Greg

[porcupine73]

Sounds good. You may have a failed duty c solenoid then (considering the AT temp light flashing). I'll look up the method to get it to flash out the code.

[nipper]

16 flashes basically means

 

HEY LOOK AT ME!

It flashes to tell you there was a fault in the tranny the last time you used the car.

Beyond that you have to do the magic to read the code. Its fairly simple. Do a search on torque bind code and it should come up.

 

The fuse may not help you, as odds are that you have a failed Duty C solenoid. Also at that mileage may pay to rebuild the clutchpack, especially since the car has been like this for 2 years.

 

nipper

[porcupine73]

Grounding terminal # 5 of connector B82 a 6 pole black, right side of steering column. Trouble codes will be displayed through AT Temp light. There

are 14 possible trouble codes communicated from the TCU.

 

[porcupine73]

This is what the transfer clutch looks like (it's the rear extension housing of the AT, where the propeller shaft to the rear diff connects.)

 

The duty c solenoid is the gold colored thing with the wire coming off of it near the lower right of the pic.

[Lucenut]

When you say "do a search", do you mean like a google search?

 

16 flashes basically means

 

HEY LOOK AT ME!

It flashes to tell you there was a fault in the tranny the last time you used the car.

Beyond that you have to do the magic to read the code. Its fairly simple. Do a search on torque bind code and it should come up.

 

The fuse may not help you, as odds are that you have a failed Duty C solenoid. Also at that mileage may pay to rebuild the clutchpack, especially since the car has been like this for 2 years.

 

nipper

[nipper]

When you say "do a search", do you mean like a google search?

 

No use the internal search feature here.

 

Of course somone could just post the trouble codes

 

nipper

[johnceggleston]

with the flashinfAT TEMP light and torque bind you are sure to have a bad duty c solenoid in the rear extention housing of the trans which contains the transfer clutch for the sending power to the rear wheels.

 

the EWD fuse probably will have no effect on the torque bind. the duty c (pluss 2 gaskets) can be bought at an online subaru parts dealer for less than 100$ the labor at a shop is about 250$ - 300$. or you can go to the dealer and they will do it for 900$.

 

let us know what you learn when you put in the fuse.

[Lucenut]

OK, I'll measure the tires and try the fuse saturday and let you all know!

 

Thanks.

 

with the flashinfAT TEMP light and torque bind you are sure to have a bad duty c solenoid in the rear extention housing of the trans which contains the transfer clutch for the sending power to the rear wheels.

 

the EWD fuse probably will have no effect on the torque bind. the duty c (pluss 2 gaskets) can be bought at an online subaru parts dealer for less than 100$ the labor at a shop is about 250$ - 300$. or you can go to the dealer and they will do it for 900$.

 

let us know what you learn when you put in the fuse.

[Gloyale]

When turning sharp, backing out of the driveway you feel the tires chirping sorta (like in the old 4WD trucks I'd had when locked into 4-low).

 

Makes sense, in 1st and Reverse ranges, the AWD transfer is increased. If you were to keep backing up and turning it should sense the bind and release abit. But in Reverse the AWD is at max, almost locked.

 

And to clarify The OP has never stated that the AT Temp light has flashed, it was brought up in reference to pulling codes.

 

I think he just needs a tranny flush.

[Gloyale]

Waiting for the gurus to show up, I can already tell you one thing. Under the hood, near the firewall I think, is a fuse holder marked «two wheel drive" or «front wheel drive». If you put a fuse in there (I guess 20 amp shoud do) Your car will be front wheel drive. If it's a problem with the AWD it will subside. If everything stays the same, then it's something else.

 

 

This post is backwords.

 

If the binding subsides with the use of the FWD fuse, the Clutches are functioning normally, and not siezed. The trouble would then seem to lie outside of the AWD clutches. Perhaps in a *data* issue, meaning the TCU is deciding for whatever reason (TPS signal, Speed sensor, etc.) to engage the AWD too much.

 

If the binding persists, even with the insertion of the FWD fuse, it means the problem certainly is with the AWD clutch. The two main things that can happen:

 

1. Failed C solenoid or C solenoid wire.

 

2. Seized clutch pack

[Lucenut]

Wow, I looked up this thread and got utterly confused: http://www.ultimatesubaru.org/forum/showthread.php?t=85418&highlight=torque+bind

 

I'll just check back in after trying the fuse and measuring the tires.

[Lucenut]

Are you saying it's normal to have some binding in reverse and 1st gear?

 

I did say the AT Temp Light flashes 16 times. I went and tried it after it was mentioned.

 

Greg

 

Makes sense, in 1st and Reverse ranges, the AWD transfer is increased. If you were to keep backing up and turning it should sense the bind and release abit. But in Reverse the AWD is at max, almost locked.

 

And to clarify The OP has never stated that the AT Temp light has flashed, it was brought up in reference to pulling codes.

 

I think he just needs a tranny flush.

[nipper]

Are you saying it's normal to have some binding in reverse and 1st gear?

 

I did say the AT Temp Light flashes 16 times. I went and tried it after it was mentioned.

 

Greg

In Reverse low, and ful throttle the car forces a 50/50 split.

 

All AWD cars (that actually are awd and not some funky weeny system) will show some initial

TB when backing out of a parking spot at full lock. When going forward there should be no TB in a tight turn.

 

If the light flashed 16 times when you start the car, then shut it off, then restatr the car and dont drive it, it may not flash again. Thats because the tranny hasnt done anything yet to need the solenoids operating.

 

nipper

 

nipper

[Lucenut]

Still sorta over my head. I don't think I've ever backed out of the driveway or anywhere for that matter at full throttle.

 

About the flashing AT light flashing are you just saying it won't flash again until you actually drive the car?

 

In Reverse low, and ful throttle the car forces a 50/50 split.

 

All AWD cars (that actually are awd and not some funky weeny system) will show some initial

TB when backing out of a parking spot at full lock. When going forward there should be no TB in a tight turn.

 

If the light flashed 16 times when you start the car, then shut it off, then restatr the car and dont drive it, it may not flash again. Thats because the tranny hasnt done anything yet to need the solenoids operating.

 

nipper

 

nipper

[frag]

This post is backwords.

 

If the binding subsides with the use of the FWD fuse, the Clutches are functioning normally, and not siezed. The trouble would then seem to lie outside of the AWD clutches. Perhaps in a *data* issue, meaning the TCU is deciding for whatever reason (TPS signal, Speed sensor, etc.) to engage the AWD too much.

 

If the binding persists, even with the insertion of the FWD fuse, it means the problem certainly is with the AWD clutch. The two main things that can happen:

 

1. Failed C solenoid or C solenoid wire.

 

2. Seized clutch pack

 

Gloyale, if you follow the link below (and there are others), you'll see a case where after inserting the fwd fuse the torque bind went away. It was afterwards found that the clutch pack was the culprit. Must mean something...

http://www.ultimatesubaru.org/forum/showthread.php?t=81062&highlight=torque+bind

[nipper]

Still sorta over my head. I don't think I've ever backed out of the driveway or anywhere for that matter at full throttle.

 

About the flashing AT light flashing are you just saying it won't flash again until you actually drive the car?

 

GRRR

 

you get 50/50 split during the following conditions

 

Full throttle

 

-OR-

 

low gear

 

-OR-

 

Reverse

 

whats not to understand?

 

 

One more time then i am bowing out

 

you drive the car at 1pm. at 115 pm you have an internal transmission failure. you shut off the car and start it at 3pm. When you start it at 3pm the light will flash to tell you something failed during that 1pm drive.You shut the car off, not having moved it or put it in gear. you restart the car at 303 pm. Since you did not do anything for the transmission computer to send any signals to anything in the tranny, as far as it is concenred during that run cycle everything is fine. So when you shut the car off and restatr it at 310pm, the light will not flash.

 

nipper

[Gloyale]

Gloyale, if you follow the link below (and there are others), you'll see a case where after inserting the fwd fuse the torque bind went away. It was afterwards found that the clutch pack was the culprit. Must mean something...

http://www.ultimatesubaru.org/forum/showthread.php?t=81062&highlight=torque+bind

 

 

This is the quote from that thread, where the OP decribes the trouble.

 

1. Torque Bind (TB) - Occasionally. If the front wheels slip when accelerating, there's a slight delay before the rear wheels kick-in. If I then make a turn, TB is apparent. However, if I accelerate slowly/easily (no slip), and then make a turn or pull into my parking space @ work, there is no TB.

In his case, there was also a noticable delay, meaning he has worn clutch pack. Only after he get's some lip, does the back kick in, thne it won;t disengage.

 

It' a little different issue. In his case the TCU was trying to compensate for worn clutches by keeping the transfer pressure high.

 

But if you read his last post in the thread, he really was having more of a delay issue getting the AWD to work, than a Torque Bind issue.

 

Backing up while turning will produce some binding, the test is whether it releases if you keep going around the turn.

[frag]

This is the quote from that thread, where the OP decribes the trouble.

 

 

In his case, there was also a noticable delay, meaning he has worn clutch pack. Only after he get's some lip, does the back kick in, thne it won;t disengage.

 

It' a little different issue. In his case the TCU was trying to compensate for worn clutches by keeping the transfer pressure high.

 

But if you read his last post in the thread, he really was having more of a delay issue getting the AWD to work, than a Torque Bind issue.

 

Backing up while turning will produce some binding, the test is whether it releases if you keep going around the turn.

 

Not sure I will keep at this any further than this post, but read this other thread where the OP HAS a case of torque bind that was alleviated by putting the FWD fuse in.

http://www.ultimatesubaru.org/forum/showthread.php?t=84696&highlight=torque+bind

What is Nipper's verdict? «Drive in FWD mode, it makes the car more stable to drive. you dont have a duty C problem, you have a clutchpack problem. You can either save money a- for a used tranny, or b - rebuild the clutch pack.

Nipper»

 

What I'm getting at is that when you have torque bind with an AT and you put the fwd fuse in and the torque bind goes away, it CAN mean you have a problem with the clutch pack. That all I wrote in my first post and, writing that, I was not putting things backwards.