2005 Subaru Outback AWD engagement questions, and other issues...

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Hi everyone, i have a client that thinks they have a problem with the AWD system on a 2005 outback 2.5L. It has about 95K miles, and they swear to me that only the drivers side front wheel is "working", and that the AWD is not, nor the passenger side front wheel... :unsure::unsure::unsure::unsure: They also think this car is "totally unsafe" in the rain because of this "issue", and forget about the snow. They have a steep driveway, and supposedly, it can not make the driveway "like my past subarus" They just picked up this low milage car about two years ago and within months it had a check engine light, even the drivers side power window switches gave out recently, that im replacing for them this week.

It does have a check engine light for a PO420 code, (on Subarus if the check engine light is on the cruise control will not work either) and they were quoted around $1900 for new catalytic converter's and exhaust system.. I think it just has a slight leak at or around the headers drawing in fresh air causing this check engine light, so i put a "anti-fouler" on the 2nd bank o2 sensor, to get it to pass NY inspection. If i clear the light, and drive it a little aggressively for 50-60 miles, i can get it to pass, but once they start driving, the light will still come back. The engine sounds like a typical subaru, of that era so i dont know if it has a exhaust leak or not... :rolleyes: Also the head gaskets i believe are original, so that's another $2,000 repair. Is it possible that they are going out, and maybe caused the catalytic converter's to "fail"? I cant remember if it uses any coolant, but they never pop the hood. From what i remember, last time i changed the oil, i had to add coolant. I think.. Also it might use a little oil, because when i changed it, it was low on the stick, so i gave them a QT, and told them to check it somewhat frequently, or every 1500 miles.. I dont think they ever did, but the engine was never ran dry either as it seems to never go below at QT low.

Back to the AWD: The AWD and AT TEMP light do not blink, and goes off after the car is started, so the computer thinks everything is fine with the AWD im assuming. Could this Subaru need all the fluids changed in the differential/transmission/transfer case - if it even has one with like a LSD additive added for a little more grip? Where should i start investigating this? Aren't subarus mostly FWD, until it senses slip, then it sends power to the rear wheels? They dont want ANY slip because to them its "unsafe".

What would you do in this situation? Where would you start? I told them to sell it off, and buy a 2011 or never one since they still want to stick with Subaru.
The car is in great physical condition with no rust on the body, and it is loaded with leather and other "premium" options that subaru offered in 2005... Its a little soft in the suspension, but rides very nice, and is somewhat "peppy" still. Transmission feels great, and there are no clunks or anything like that... yet.

Suggestions please. thank you!.

PS: I know some of you are thinking, RUN AWAY and dont touch this car, but they are "very understanding" of these issues, and would never blame me when it blows up. I told them months ago "you are on borrowed time", they just basically want it to run and drive, and a new inspection sticker.... and AWD working if its even "broke".

Thank you all.
 

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AS far as I know the Subie has always the AWD engaged and will not run only in FWD. If memory serves there is a fuse that one can pull to disconnect the AWD. So a look in the manual may help especially the chapter on towing, I think it's there where they show how to disconnect it.
 
EJ253 with the 3 stud exhaust flanges? The gaskets are probably on their way out. Start with what you know is wrong, check the fuse is removed IIRC it is near the shock tower, the real old ones was pass side IIRC these are on the drivers side main fuse box, the 05 with automatic should still have it but with no AWD light it is probably not in there which is normal mode.
Make sure the driveshaft is present, it sounds bat sh.. crazy but people do it when they have binding issues in the AWD system. Clutch drum and AWD duty solenoid failures are common, LS additive doesn't help.

It is not too difficult to repair if you have done it before but if you don't want to spend time learning it get a good used one, these things are a dime a dozen with good transmissions and transfer cases, they are usually scrapped for blown HG issues.
 
I never even thought about the driveshaft. LOL. You never know with used cars, so i will check fuse, and driveshaft, i dont think i want to tear into this very deep, unless its a sensor replacement or something like that.
Thanks!
 
The front half of the shaft and center carrier will be there, the yoke keeps the fluid in. AFAIK they pop the rear shaft when this is done but I am not very familiar with it, I never did it.
Edit: This is even more possible if the car was towed behind an RV.
 
How bald are the tires?

If the AWD fuse is in, the AWD light will illuminate. At least it did on my previous '97 LGT and I'm lead to believe it's the same based on the owner's manual for this car. 2005 Outback OM

Subaru's AWD system is permanently connected at the center-diff. If the AWD system failed, it would result in something like only 5-10% of the torque going to the rear wheels (effectively no AWD). The solenoid-operated clutch varies its duty cycle to transfer varying amounts of torque, front-to-rear, which is why it's tough to say what the actual split is at any given time.

With that said, most of Subaru's AWD system utilize front and rear open differentials. If this vehicle does not have Vehicle Dynamics Control I do not believe it has the capability to transfer torque from side to side by actuating individual brakes. This means that if a tire lifts and has ZERO traction, it will spin just like a FWD car and have an impossible time transferring torque to the rear.

The traction control or VDC light should be flashing while the slippage is occuring. Traction control limits torque during wheel slippage and Vehicle Dynamics Control (was an option and not standard in 2005, maybe only in upper trims, I don't know) will apply braking power to individual corners to try to assist the AWD system (prevent excessive wheel slippage)
 
How bald are the tires?

If the AWD fuse is in, the AWD light will illuminate. At least it did on my previous '97 LGT and I'm lead to believe it's the same based on the owner's manual for this car. 2005 Outback OM

Subaru's AWD system is permanently connected at the center-diff. If the AWD system failed, it would result in something like only 5-10% of the torque going to the rear wheels (effectively no AWD). The solenoid-operated clutch varies its duty cycle to transfer varying amounts of torque, front-to-rear, which is why it's tough to say what the actual split is at any given time.

With that said, most of Subaru's AWD system utilize front and rear open differentials. If this vehicle does not have Vehicle Dynamics Control I do not believe it has the capability to transfer torque from side to side by actuating individual brakes. This means that if a tire lifts and has ZERO traction, it will spin just like a FWD car and have an impossible time transferring torque to the rear.

The traction control or VDC light should be flashing while the slippage is occuring. Traction control limits torque during wheel slippage and Vehicle Dynamics Control (was an option and not standard in 2005, maybe only in upper trims, I don't know) will apply braking power to individual corners to try to assist the AWD system (prevent excessive wheel slippage)
Thank you for the detailed response. The tires are like new and filled to recommended psi.
So if im reading this correct, i want to AWD light to be on after i start the car? It does turn on for a couple secs before you start it.
On this website, it seems you cant even get VDC unless the turbo 4, or H6? is the right? This is just the limited 2.5L with all the options, but base engine, and im assuming they saved the VDC for the more powerful engines.

I will physically look the car over this weekend, to confirm the 2nd half of drive shaft is present, and the fuse for the AWD is either there or not? If all else checks out, what would be the best way to "test" the AWD, lift the car and see if the rear wheels move? find some gravel and see if it will engage the rear wheels?
 
If in fact only the left front wheel has power, then I would expect with the left wheel on the ground and the right wheel off the ground, the right wheel should rotate if in neutral.

Perhaps a way to check is try doing a spin with all 4 wheel on loose dirt to see what wheels spin.

I had a 2006 Forester that the right rear wheel was not spinning. The axle shaft was not seated in the differential. I had bought the car with 150k miles on it. Not sure what it's history was.

Your P0420 probably will end up being a cat issue. The Forester (Japan made) has the cat in the header pipes. Outback (USA made) has cats all over the place which makes them really expensive to fix. Since this is a NY car, I believe they are under CARB requirements as is California. At least in California only CARB cats can be used.
 
Are you the primary person who maintains their vehicle?

Depending on how much they got the car for, I’m not sure I’d dump it just yet. Head gasket issues were still prevalent in the mid aughts, regardless of what some people tell you. Based on my reading (and experience with my ‘97 LGT), they tend to go at around 125k+ (mine went at around 150k and was fixed by the PO, just prior to selling it to me). Based on this, I’d think you’ve got some time Before that becomes an issue.

With the anti-fouler installed they should be able to get the P0420 to clear, so long as they‘re willing to (or have someone like) give it the beans every so often or just prior to taking it in for emissions testing. I’m surprised it doesn’t keep the code off all the time.

Thank you for the detailed response. The tires are like new and filled to recommended psi.
So if im reading this correct, i want to AWD light to be on after i start the car? It does turn on for a couple secs before you start it.
On this website, it seems you cant even get VDC unless the turbo 4, or H6? is the right? This is just the limited 2.5L with all the options, but base engine, and im assuming they saved the VDC for the more powerful engines.

I will physically look the car over this weekend, to confirm the 2nd half of drive shaft is present, and the fuse for the AWD is either there or not? If all else checks out, what would be the best way to "test" the AWD, lift the car and see if the rear wheels move? find some gravel and see if it will engage the rear wheels?

I’m sorry if I was confusing. I meat that the AWD light would remain on if there was a problem. The lights all lighting as you start the car is merely a lamp check.

I’m sorry to hear that the tires are new. Bald tires would have been an easy fix.

I believe VDC was standard in Subarus in 2009. My ‘08 STI had it and it appears that high-performance models had it prior to that. I see no reason not to trust your link and come to the conclusion that the subject Outback does NOT have VDC.

If in fact only the left front wheel has power, then I would expect with the left wheel on the ground and the right wheel off the ground, the right wheel should rotate if in neutral.

Perhaps a way to check is try doing a spin with all 4 wheel on loose dirt to see what wheels spin.

I had a 2006 Forester that the right rear wheel was not spinning. The axle shaft was not seated in the differential. I had bought the car with 150k miles on it. Not sure what it's history was.

Your P0420 probably will end up being a cat issue. The Forester (Japan made) has the cat in the header pipes. Outback (USA made) has cats all over the place which makes them really expensive to fix. Since this is a NY car, I believe they are under CARB requirements as is California. At least in California only CARB cats can be used.

Great catch on the CV shaft not being seated; however, I’m not sure how that would affect the overall driveability. Wouldn’t the rear differential over-spin on the unseated side, causing a loss in power due to zero “traction”? I’ll defer to you, since you personally experienced it. Could you elaborate on the symptoms, though?

Anyway, when I attempted to replace my rear wheel bearing I noticed the retention ring did not come out with the CV shaft and was stuck in the rear differential. I had to pay my mechanic more money than the job was worth, all because they had to spend time getting that darned thing out, bending it back into shape an re-using it. Oddly enough, you CANNOT buy just the retention ring. If I had tried to pop it in “as best as I could” who knows if the splines would have come out enough to disengage. As I mentioned before, an unseated CV shaft could cause the issue des

Another good suggestion to find a gravel road and gun it to see which wheels are putting out power. It would be even better to record the trial, so you can go back and compared frame-by-frame, so to speak.
 
Are you the primary person who maintains their vehicle?

Depending on how much they got the car for, I’m not sure I’d dump it just yet. Head gasket issues were still prevalent in the mid aughts, regardless of what some people tell you. Based on my reading (and experience with my ‘97 LGT), they tend to go at around 125k+ (mine went at around 150k and was fixed by the PO, just prior to selling it to me). Based on this, I’d think you’ve got some time Before that becomes an issue.

With the anti-fouler installed they should be able to get the P0420 to clear, so long as they‘re willing to (or have someone like) give it the beans every so often or just prior to taking it in for emissions testing. I’m surprised it doesn’t keep the code off all the time.



I’m sorry if I was confusing. I meat that the AWD light would remain on if there was a problem. The lights all lighting as you start the car is merely a lamp check.

I’m sorry to hear that the tires are new. Bald tires would have been an easy fix.

I believe VDC was standard in Subarus in 2009. My ‘08 STI had it and it appears that high-performance models had it prior to that. I see no reason not to trust your link and come to the conclusion that the subject Outback does NOT have VDC.



Great catch on the CV shaft not being seated; however, I’m not sure how that would affect the overall driveability. Wouldn’t the rear differential over-spin on the unseated side, causing a loss in power due to zero “traction”? I’ll defer to you, since you personally experienced it. Could you elaborate on the symptoms, though?

Anyway, when I attempted to replace my rear wheel bearing I noticed the retention ring did not come out with the CV shaft and was stuck in the rear differential. I had to pay my mechanic more money than the job was worth, all because they had to spend time getting that darned thing out, bending it back into shape an re-using it. Oddly enough, you CANNOT buy just the retention ring. If I had tried to pop it in “as best as I could” who knows if the splines would have come out enough to disengage. As I mentioned before, an unseated CV shaft could cause the issue des

Another good suggestion to find a gravel road and gun it to see which wheels are putting out power. It would be even better to record the trial, so you can go back and compared frame-by-frame, so to speak.
I am mostly the primary person, unless special equipment is needed or something "major" such as transmission, or head gaskets. For now we will fix it, because it does still drive nicely, and has no rust.

The AWD lights goes off and does not blink or anything "odd"


Regarding the anti-fouler, and P0420 code, i only used one (package came with 2) because i was afraid of getting that p0420 code cleared but setting a P2096 - Post Catalyst Fuel Trim System Too Lean Bank 1, maybe i should try the other one? With the one that's on it currently, if i clear the code, and drive it aggressively-ish as in different then the owner where it might never see 3k+ rpms for about 50-60 miles the code does stay off, and i can get it to pass no problems. But once they drive it, it comes back within days.

Also to note, this right front wheel had a bad wheel bearing, and extremely warped brakes (both sides) that was replaced maybe a year ago, could the bad wheel bearing, or brakes damaged anything that i did not catch? I don't think the bearing had play from what i could remember, just a very loud hum, and the steering wheel would vibrate excessively while on the brakes. After replacement, it drove like a dream, straight, no vibrations or anything of the like, after repair i did give it WOT run 0-70 and i called the problem fixed.... the front tires did chirp, but it does not have enough power to "light them up lol" But now im thinking is the CV or something like that not "seated" correctly. I find it had to believe the car would even still move if that was the case... But they have been telling me since they got the car about the AWD, and this was before repair so idk.

I think i will try the gravel road trick after a in depth visual inspection, and record it like you suggested, so i can see what tire is doing what. Also will try jacking individual tires off ground and seeing if any move freely.


Thanks!!
 
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If “only the drivers side front wheel is working,” there is a disconnect. If the passenger wheel was spinning or free, then with the open diff, there’d be no power to the ground at all up front. It would also pull like a sob every minute of every day if somehow only one side put power to the ground.

id definitely jack it up, all 4, rotate wheels and driveshafts and just get a feel for what’s going on. IIRC the rear system is connected unless power is applied to reduce AWD engagement, hence why installing the fuse drops it instead of pulling a fuse. So with the car off and in neutral, the front and back should be connected. I could be very wrong here; I owned a 5mt and those are different.

make sure you understand the type of AWD here. The 5mt is truly a center diff with limited slip variance between front and rear. Last time I checked, the ATs are a FWD with rear wheel assist, driven NOT through a ”center diff“ but through a modulated viscous clutch/coupling. these are very different systems.

jack all 4 up. Rope one wheel to not spin. Spin the one on the opposite side. What happens?
 
The axle out of the spline on rear of Subaru Forester gave no issues I noticed. The way I found the issue was when changing the read differential oil. I noticed that the right side had a much larger gap then the left side. The car was not jacked up. I was able to move the right axle in and out of the differential side. The left side didn't move so I either smartly or stupidly used a short 2x4 and hammer to push it back in. It seemed to have clicked in as it was then unable to be moved out as before. I drove the car some 40k miles after.

Someone then rear ended the car and totaled it as they hit the trailer hitch and bent the frame slightly.
 
Ex-wife had a 2005 Legacy. I recall there is a fuse that gets installed for front wheel drive, which was a necessary step if you had to use the donut spare. I don't remember if installing that fuse causes the AWD light (I would think it would), but I know it disengaged the rear wheels.
 
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