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AWD not working? Central diff problem?


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I have a 97 Legacy OBW AT EJ25. Last winter I had a problem while trying to drive up a driveway that was covered in snow. The front tires were spinning and the rear tires were doing nothing. I tried a whole bunch of times and I just couldn't make it up.

 

Any ideas what might be happening? I replaced the Duty C Solenoid over a year ago and there are no CELs or AT Oil Temp lights flashing. Someone said something about the center diff having failed. How can I check that?

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Someone said something about the center diff having failed. How can I check that?
you can't, automatics don't have center diff's.

 

center diff's are on manaul trans and they only fail to "locked", not open.

 

measure voltage and see if the Duty C is getting power or not. is it possibly in FWD mode? the AT light isn't on - so i guess you probably checked or noted that it does work though (meaning the bulb isn't non-operational)?

 

not sure why it wouldn't give anything, maybe the clutches inside are hosed? if the clutch/hub/drum (forget the name) sheared, which happens, i would expect other symptoms/noises. so should be Duty C or clutch related....maybe?

 

not sure if a Duty C can stick "on" all the time, essentially in "FWD mode" without throwing a code. would be the first time i've heard of that.

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you know, i'm not sure exactly how that circuit works since its receives a varying signal. it needs to be getting something because default (no signal at all - unplugged) is locked 4WD so to speak which you obviously don't have.

 

The TCU or the big connector on the passengesr side of the engine bay are the only two places i know of that are easily accessible, not sure which wire it is though.

 

You could also just unplug the transmission connector. The trans will run in purely mechanical mode - which is "locked" 4WD. if you unplug the connector you should have severe binding from the 4WD. if you get 4WD/binding then it's an external issue - wiring or TCU. if it doesn't bind at all then it's an internal issue - clutch pack related.

 

it'll be gutless since default it 3rd gear, but perfectly drivable.

 

that's probably the simplest test.

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you know, i'm not sure exactly how that circuit works since its receives a varying signal. it needs to be getting something because default (no signal at all - unplugged) is locked 4WD so to speak which you obviously don't have.

 

The TCU or the big connector on the passengesr side of the engine bay are the only two places i know of that are easily accessible, not sure which wire it is though.

 

You could also just unplug the transmission connector. The trans will run in purely mechanical mode - which is "locked" 4WD. if you unplug the connector you should have severe binding from the 4WD. if you get 4WD/binding then it's an external issue - wiring or TCU. if it doesn't bind at all then it's an internal issue - clutch pack related.

 

it'll be gutless since default it 3rd gear, but perfectly drivable.

 

that's probably the simplest test.

 

That is very good advice. Where is the TCU located?

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clutch plate friction disks (there are like 9 of them) in the rear output shaft of the trans may be worn and not catching.

 

so even though duty c works or is new, there is just no way for the car to know if the plates are worn and slipping or not.....it may be turning but not turning the rear driveshaft if the plates are trashed. Car being towed with rear wheel down could cause that, or mismatched tires, etc.

 

please check under hood to make certain nobody put a fuse in the FWD holder.

Edited by bheinen74
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clutch plate friction disks (there are like 9 of them) in the rear output shaft of the trans may be worn and not catching.

 

so even though duty c works or is new, there is just no way for the car to know if the plates are worn and slipping or not.....it may be turning but not turning the rear driveshaft if the plates are trashed. Car being towed with rear wheel down could cause that, or mismatched tires, etc.

 

please check under hood to make certain nobody put a fuse in the FWD holder.

 

 

Copy that. I plan to disconnect the TCU and see what that does. If it does not result in binding then I know I got a bad clutch pack.

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it's held in place by two bolts and is a rectagular...i want to say "silver" box, though my memory is'nt perfect and that could vary. it's close the to steering wheel and not against the fire wall if that makes sense. the bolt heads face the floor and threads point directly up.

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Gentlemen, an uPdate. I went to my friends garage and put the car on the lift and into drive. The front tires spun but the read did not. H central drive shaft was not spinning but I could rotate it by hand. I unplugged the tcu and I would not induce any binding. No flashing lights on start up. Thoughts?

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It appears I'll need a new clutch pack. Does anyone know the part number? Are there other things I need to do while in there? I did not check the drive shaft turning with the tcu unplugged, which I will just to completely make sure before cracking open the Trans. Any suggestions for other things to test or try?

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or it could be a busted clutch drum. we've seen that before. but which ever, clutch plates or the drum, it is in the rear extension housing.

 

pssst, don't tell any one but winter is just around the corner, don't delay.

 

Yeah I'm taking care of this now so I make it through the winter ok. Can you recommend things to do while in there?

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good job getting that figured out, it's definitely in that rear extension housing then.

 

it needs to be pulled apart to inspect and see what's going on. inspect clutches and make sure the hub drum isn't sheared, it happens. whatever is broke, fix it.

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good job getting that figured out, it's definitely in that rear extension housing then.

 

it needs to be pulled apart to inspect and see what's going on. inspect clutches and make sure the hub drum isn't sheared, it happens. whatever is broke, fix it.

 

Yup that's the plan. I would like to make a list of the most likely failed components and have them on hand when I do this repair. I'll be at my buddy's garage and will have one nigh to get it all done. So, what does one find in the tail extension housing and what is most likely to have gone wrong?

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Gentlemen, all of this has suddenly become a non-issue owing to the fact that my Outback died while driving about an hour ago. I was going about 25mph down a side street when I started hearing a squeaking noise. A few seconds later the engine cut out and I coasted to a stop. The starter will turn and turn but the engine doesn't start up. I pulled both timing covers and the belt seems to be nice and tight. I had it towed to my buddy's garage and will deal with it in the morning.

 

I'll pick up on the transmission issue once I resolve the engine issue.

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There goes all our fun :(

 

I know. It downright sucks for me, as well.

 

I hope it's not the headgasket(s). They were replaced 1.5 years ago but the guy used felpro HGs (I did not know this at the time). I checked the radiator and the fluid seemed low, but I was not overheating nor did I smell any burnt oil. I'll find out more in the morning.

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Headgaskets dont make a noise when it goes bad, The squeel can be hideous Do all your accessories turn when the engine cranks? Do you still have the alt belt connected. Does it spin freely. Squeel noise is usually a belt squeeling, and we all know where the belts reside.

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