What kind of car is it? Need the year, make and model. Could be as simple as a tire scrubbing, or if front wheel drive, it could be a cv joint going bad. How many miles are on the car?

Need a little more info. How many miles, year, type of car, front wheel drive etc. Are you hearing any sounds? If it sounds like squeaking noise, you could be a power steering pump or rack and pinion. If you turn you wheel to full lock this could cause a vibration. If it sounds like a thump it could be a wheel bearing and if it makes a clunking noise, it could be a cv joint. Also, worn brake pads have wear indicators on them so they make a god awful scraping noise to let you know to get your brakes done.

Without knowing what year car you have, sounds like you need a tune up, your knock sensors need replacing, or at very least set your ignition timing. Anti knock sensors detect donotation or pinging and retard your ignition to save the engine. Engines will ping when under a big load such as going up a hill. This is most likely why your car bucks going up a hill.

If the tires have ply separation and uneven tread, it can make this noise. Also, turning too hard to the limit and causing a strain on the power steering pump.

The car is a 1997 Subaru Legacy Outback with 120,000 miles on it. It has all wheel drive so there is a differential in the front and the back. The knock sensor was replaced today and the bucking or hesitation seems to be gone. I am also running a can of Seafoam through the fuel system. Anyhow, the vibration does not seem to be related to the anti-knock sensor because the vibration is still there.

The vibration does not occur when going straight, or is at least much less pronounced. It is there when turning left or right. It is not there when not moving. I can cut the wheel sharply and there is no vibration until I start moving. I am not hearing any sounds with the vibration. It is more like a low frequency rumble. I have checked the fluids on the transmission and both differentials and they look clear and at the proper levels.

The mechanic I had do the anti-knock sensor siad he didn't think there are any seal problems because the levels are good so there don't appear to be any leaks. He thinks it coul dbe a valve sticking but I'm not sure if he means in the transmission or the differential. He also mentioned that it might be the CV joint. The boots were all in good condition, for what that's worth.

If it were a transmission problem, wouldn't I get the vibration when going straight as well as when turning?

I have the same feeling when I turn the wheels hard to back my full size Ford van out of a parking space. I thought at first my transmission was slipping, but it only ocurred when going very slow and turning hard. I finally realized it was the tire tread. It was the way the tread gripped the macadam at an odd angle and slow speed.

Try this: Turn the wheels hard and slowly back up. When you hear the sound, stop and straighten out the wheels and move slowly again. If the noise stops, I would suspect the tires.

On a Subaru I can think of two things - a problem in the limited slip rear differential or in the center differential that controls the front to back power division. Did you have the rear diff fluid changed recently, and if so did you add a friction modifier? Come to think of it, it wouldn't be that expensive to do that & see if it helps.

Does it make the noise when moving and alternately turning the car left and right like going through a slalom? If so it may be a CV joint or wheel bearing. Does it do it under power or during deceleration?

I don't think it is the tires. I just changed from all-seasons to snows and it did it with both types of tires.

On the differential fluid. I am embarassed to admit that I have never changed it. What is a friction modifier?

I haven't noticed the vibration during deceleration. It is hard to tell if the vibrations I feel under power are partly due to this or not. If so, it is much less pronounced.

I know what you mean by doing a slalom but to what extent? If I do a hard slalom by alternately cutting the wheel fully in both directions I would definitely expect to get the vibration since I get it when going in either direction slowly to turn into a parking space. Are you talking about doing a slalom by only partially turning the wheel and see if the vibration is still there?

The most interesting thing I can think of is that it only does this when the car is warm after having driven it for several miles.

Since the vibration is only there when turning the wheel, I would rule out engine or transmisssion. I'm not sure if your car has a limited slip differential or standard differential, but if it does, you should definitely have the fluid changed and add a bottle of friction modifier. Friction modifier is only added to a limited slip differential. You do not need to add it to a standard differential. A limited slip or posi rearend will send power to both rear wheels in situations where traction is reduced. Once one wheel starts spinning a limited slip will lock up using a series of clutches and send power to the other wheel as well to increase traction. The friction modifier allows these clutches to function properely. Without this additive the rearend will be noisey and not work correctly. I don't think this is your problem based on your description, but you should still have the fluid changed. From your description, I think you need to have your wheel bearings inpected.

I did a long drive yesterday. (About 2 hours each direction)

Interestingly enough, it seems like the vibration/rumbling was much less pronounced after a long trip. Maybe it was my imagination. But, if not, it would mean that this effect does not exist when the car is cold, shows up after a 15-20 minute drive and then fades away again if the car is driven farther. This morning I did a left hand turn into a parking space and didn't notice the rumbling but the ground is wet here today so maybe that allowed the tires to slide more easily on the ground.

One thing I did notice is that the car does seem to have more pep and slightly better gas mileage now. Replacing the anti-knock sensor (is that the same as an oxygen sensor?) and running some Seafoam through the fuel system seems to have really improved things. I suppose it is possible the two issues are related but I don't see how.

One other irritating problem that the car has is a squeaky brake. It is the rear drivers side. Two mechanics have tried to resolve the issue, several time each, but with no luck. They have tried to clean out some of the parts and lube the emergency brake cable. It seems like the brakes just aren't releasing fully. After I hit the brakes and release the pedal I hear a faint sqeaking that will sometime go away until I hit the brakes again. The braking force it not enough to feel but it is enough to heat up the brakes and create a burning smell.

Oh well, I guess these are issues to be expected when a car hits 120k miles.

Gee, my Ford Ranger has 181,000 plus miles on it and it doesn't make those kinds of noises and smells! Of course, i take better care of it! Maybe you ought to try that, too!

Brakes:

Maybe you have a sticky piston on one caliper or a kinked or pinched brake line. Parking brakes usually use a separate mechanical cable. (not knowing Suburu) This will cause a pad not to retract properly and burn.

Old style rear drum brake pistons also can stick. A bad spring on drum types can also cause that problem.

I had a sticky caliper on my Corvette years ago. I had to replace the whole caliper as it was too pitted to rebuild.

You need to go ahead and bring it in to a reputable shop in order to properly diagnose the problem, and effect the correct repair.

bushleague,
"You need to go ahead and bring it in to a reputable shop in order to properly diagnose the problem, and effect the correct repair."
. What planet are you from??

The knock sensor is not a oxygen sensor. A knock sensor is located on the engine usually in a coolant passage. This sensor detects engine knock or denotation(pinging) and tells the computer to retard the timing so your engine doesn't blow up. The oxygen sensors are located in the exhaust. They are usually located in the exhaust manifold and after the cat. These sensors meausre the air/fuel ratio and tell the computer to adjust the fuel ratio. Sea foam is great stuff for cleaning injectors and carbon deposits from engines. The sea foam itself would smooth out a dirty engine.

Do you have disk or drum rear brakes?

There's only one sure thing about all of this: If he/she takes it to a dealer to get it fixed, they'd might as well spring for a new car, because thats how much it'll cost to have the dealer fix it!
RJ

It could very well be the transfer case. Going straight, the front and back wheels turn the same speed, turning left or right, they spin at different speeds on account of the front and back wheels going though a different turning radius. Insert the FWD fuse under the hood and road test the car, keep the road test short and at low speeds as you are not really supposed to drive with the FWD fuse in, it's more for when towing the vehicle, but going around the block once is ok. If the car runs well with the FWD fuse in then it's the tranfer case. the good news is that 99 percent of the time changing the ATF resolves the problem forever.
Does the car feel like it "hopping" or resisting to want to steer at low speeds?

I think by transfer case you may meen differential. The differentials are what control wheel speed when turning. The transfer case only transfers power from the trans to the front and rear drive shafts (hence the name).

You mentioned you haven't changed the fluid in the differentials so I would say that I'm 90% certain that's your problem. If it's a limited slip differential it has clutch pads in it that wear similar to a trans. Without proper maintenance these pads wear out prematurely and will not "slip" allowing your outside tire to spin faster than the inside on tight turns. As a result you drag your outside tire and it makes a heck of a lot of vibration which anyone who's ever driven in 4WD on dry pavement with an open front diff can attest to.

Try changing the fluid first to see if it helps. If not you could be faced with needing a new diff which can run $600-$900 each. No, it's not a DIY project.

The only other possibilities could be (and I'm really only familiar with GM products): an intermediate steering shaft but I'm not sure if Subaru has them or not, ball joints, tie rod ends, idler and pitman arms...?

The reason your car has more pep with the new knock sensor is because, as already stated, if it's receiving a false knock reading (meaning it's sensing detonation that isn't there) it retards the timing effectively making your engine run slower and "bog down". Especially in wide open throttle situations.

Hope this helps.

No, I really do mean the transfer case located at the tail end of the tranny, not the front or rear diff. BTW, the front wheels and back wheels turn at different wheel speeds in a turn. Not just left and right wheels. They go through a different turning radius. (just watch your tracks in the snow for proof). This is why there is a transfer case. If your lock the front and rear wheels together with a 50/50 split it becomes hard to steer. It does the same as a differential but between the front and back of the car.

I guess I never realized the transfer case did all that. Does it perform that same function in 4WD vehicles or is that only on AWD transfer cases? I've always wondered but never really asked why they wouldn't have put a limited slip differential on the front end of my pick-up to use 4WD full time if I wanted. I just assumed it was an open diff but maybe it is a LSD but the transfer case is what causes the outside tire to drag.

What do they use on full-time 4WD trucks?

To the person who asked, I have disk brakes all around.

Another good piece of data on the breaks is that I can get the slight squealing sound it is making stop if I gently tap on the brakes OR I pull up slightly on the emergency brake.

On the vibration, it does feel a bit like it is hopping. I may give the FWD fuse test a try.

I am a little confused about the AWD system on the car. Some people say the LSD is clutch based but I read somewhere that it is actually fluid based. But then I am not sure what "IT" really is. Clearly there is a differntial of some sort that allows power to be delivered to both front and both rear wheels but also allow for them to spin at different speeds. I have always envisioned a three differential setup where one differential splits front and rear and two others split left and right on the front and back. In looking at the car, the front/back and left/right in the front all seem to be done in the transfer case. Anyone know what is inside this machine to make the AWD magic happen?

I did more research and found out some interesting stuff:

1. My 1997 Subaru Outback with an Automatic transmission has a clutch type center differential located inside the transfer case. (The manual transmission models have a viscous coupled center differential.)

2. My front and rear differntials are open differentials, not limited slip!!!!

3. My mechanic believes that the center differential is served by the same fluid as the automatic transmission but I haven't verified that.

It sounds like I may want to change the ATF and add a friction modifier to the new fluid. Does that sound like a reasonable first step?

By the way, a limited slip rear differential became standard equipment on the Subaru Outback in 2002 so our 2002 Subaru has it. I'm amazed I didn't know this until now. Without the LSD, if you lose traction on a front and rear wheel you have zero traction period. You are OK if you lose one or both front or rear wheels but one of each and you are SOL.

If your brakes only squeal under a very light pedal pressure, most likely you just need to the lube up the sliding pins if they are the floating type of calipers. Also, they make a disk brake lubricate that goes on the back of the brake pads.

huskymaniacny,

The good news is that diagnosing this is fairly simple: If you put the FWD fuse in and the problem vanishes, you almost definitely have a well-documented Subaru Legacy problem. Do the test.

Now for the bad news. 1990-1997 Subaru Legacies with automatic transmissions have a TSB out there for something called "torque bind." Any reputable Subaru dealer knows about it, as the TSB is many years old (the date on my copy is from 2000). The TSB number is 16-62-97. What it boils down to is a malfunction of the AWD system.

Awhile back I got the TSB and scanned it. 3 pages:

http://www.randomsoup.com/subie/subieimages/bindtsb-1.jpg
http://www.randomsoup.com/subie/subieimages/bindtsb-2.jpg
http://www.randomsoup.com/subie/subieimages/bindtsb-3.jpg

One other thing that's not as commonly known, and I'm sure most Subaru mechanics would probably argue with me about it as a result. The TCU (Transmission Control Unit) doesn't get its front speed data directly from the tranny. It gets it from the speedometer (which is fed by the tranny). If your speedo is doing weird things or you have some other speedo-to-TCU issue, it can misinform the TCU.

I only found out about the speedo's role by way of shop manuals. In there the wiring diagram makes the feed clear. Among the "things to check" for certain odd tranny behavior-- for example, shift shock going from 1st to 2nd, or when putting it in park-- is some kind of speedo issue.

Hope this helps.

Oh yeah, with respect to the center diff, yes, it shares the tranny fluid. Front diff has its own fluid, rear diff has its own fluid (obviously), center shares the tranny fluid.

Had this stuff happen to my 1995 Legacy. Not fun and not a cheap fix. The "bucking" in the TSB is what you get in its most extreme form. Mine came and went for a good long time but ultimately got worse. It was usually a light vibration, sometimes more noticeable. When most noticeable I could tell I had hopping tires. In worst cases the car simply would not take a really tight turn at pull-into-space speeds unless I gave it some more gas.

So does that mean that this was a recall issue or does it just mean that it was common enough for them to send out instructions to the mechanics on how to deal with it but not important enough for them to do a recall over it?

I think I caught this pretty early. I have disengaged the AWD and will get a fluid change with a friction modifier addititive. Maybe it will work, maybe it won't but it is worth a shot and it should help the tranny if nothing else.

To smashpdx, I had this happen to my 1992 legacy (read above your post) and in many cases replacing the ATF will fix it. My 92 did this in 1999. Bad enough that it hopped and wouldn't steer properly, I did the FWD fuse thing and the car was fine). I changed the ATF and the problem went away. It's been fine for 8 years and over 200K and is still going strong. And I pull a trailer of upwards of over 2000 LBS almost every time the car is used.
When the drain plug is removed only 4 out of 8 leters of oil come out. (you can get more out if you put the cars front on ramps so the torque converter drains). So I drained, filled then drove, then drained,filled and drove a couple more times. I bought a big 20 leter bucket of ATF. I did this till I had none left.

huskymaniacny, if I recall (no pun intended) they fixed it in MY 1998 forward. Pretty much what you said, common enough to tell the mechanics, not common enough to recall.

One thought on the fluid change, if you have a shop that will do an actual power flush that makes for good things.

stripped threads, I see you know your Subie autotrannies well. You and I have been around the 4EAT too long. :)

What you say doesn't surprise me. There are a lot of ways to gum up that autotranny. The torque bind issue in the TSB is electrical but it also makes references to physical issues (grooves/improper wear and whatnot), and then there's the whole ATF thing.

In my case the electrical was shot. Duty solenoid C was fried better than a southern catfish. Poster child for what's in the TSB. I hope that's not husky's problem. :)

The duty solinoid is replaceable with the tranny in the car no?

Yep. It's in the extension housing at the back of the tranny. It's doable in-vehicle. For some reason my extension housing was replaced as well-- never did quite understand that.

There's only one (minor) catch. The wire that runs from the harness to the solenoid is short. In my repair the tech ripped the wire in two. Then he tried to put it together with a big blob of solder and put some heatshrink wrap around it.

Well, between the wrap being crummy *and* being bathed in tranny fluid, it came off, the solder landed in contact with the extension housing, and things got shorted out pretty good. I was on a 3000 mile trip when the AT light came on. Not fun!!!

I have just found this thread and am looking for some help with a similar problem. We have a 2002 Legacy Wagon L, 5sp manual with 55K. About 2 weeks ago, the car got a bad vibration when I turn left and only when I turn left. It doesn't happen ever day, seems worse in the cold or if I am on an incline. Only happens when I am moving slowly and not fast. It is not a subtle vibration, it feels like you are driving over a rumble strip. It never happens when I go right. My left front CV joint was bad and the entire axel replaced. I thought that had fixed it but about a week later it started up again. My mechanic, who suspects the the transfer case, replaced the CV joint again just to be sure that the CV joint he put in wasn't bad eventhough he did not believe that was the problem. And of course, driving home from the shop, it did it pulling into my driveway. The thing that neither he nor I understand is if it is the transfer case (viscous coupling type) why only left. Any insights here? Could it be a steering rack problem. How do I put my car into FWD mode to test? Thanks.
E.

hey gang! i was just doing a search on my 1999 manual tranny subaru
outback, and found this thread. my car is doing almost the exact same
thing with the steering vibration. it only seems to happen when i am up
over 50 MPH. if i turn the wheel slightly to the right, there is this
low vibration, and i believe i feel it in the pedal too. then if i turn
the wheel slightly left, there seems to almost be a delay on turning.
and sometimes it jerks left. not alot but a little jerk if that m,akes
any sense. driving straight has no probs. ive got 121000 miles on her
and would like another 60000 before unloading her. had the transmission
(rebuild) and clutch changed around 97000 miles. im freaking out
thinking i need to spend another 4000 on a new transmission system.
what is up with subaru???

I don't know whats up with them but they scored very well in this years consumer report. Along with Honda and Toyota. These 3 are supposed to be among the most trouble free dependable cars. (according to them). You probably have gotten unlucky witch unfortunatly is a part of life. I've had 2 Subarus one Toyota and one Honda between me and my wife. The Toyota Echo had a water pump leak at around 50000. My civic had a Alternator fail @ 30000. Both Subarus had small issues over the years. (My first Subaru had over 416000km (260000Miles).
The day I scraped it due to rust it ran like the day it was bought new. Got a lucky one. Never had a mechanical problem. Only rust related problem.
However I do feel for you having to drop thousands in a relativly new car.

I have a 98 automatic outback with a similar problem. I notice a grinding, squealing, binding noise coming from the left front when I turn to the right. Going straight, the noise stops. I hear it turning to the left though it is much more quiet. It happens at all speeds including a slow roll and in all gears and neutral. The subaru dealer said that it was somewhat mysterious, not the wheel bearing and it sounded like the noise was coming from the transmission. They said it required a replaced transmission which would cost more than the car is worth. A transmission repair place said the differential was a little noisey but they thought it could be an inner tie rod or strut. The noise pulses with the turning of the wheels and changes in frequency depending on the speed of the wheels.
I hope it's not a transmission problem. Steering and shifting are normal. Any suggestions?

I had my subaru checked out by a front end specialist who discovered that the left front wheel bearing was bad and the wheel hub was also bad so that the bearing was moving inside the hub causing the scraping and grinding noises. The bad wheel hub made a noise that did not sound like the typical wheel bearing noise. All is repaired and working well.

I HAVE A 2007 TOYOTA CAMRY WITH 20000 MILES ON IT.
I GOT INTO AN ACCIDENT A FEW MONTHS AGO. I CRASHED INTO A CURB WITH MY RIGHT PASSENGER SIDE RIM. BECAUSE OF THIS MY RIGHT FRONT BALL JOINT AND LOWER CONTROL ARM WERE BENT. THE RIM SUFFERED COSMETIC DAMAGE BUT I ORDERED A NEW ONE.
I REPLACED THE PARTS AND GOT A WHEEL ALLIGMENT AND BALANCE.
ONCE I GOT ON THE HIGHWAY I NOTICED THAT MY VEHICLE WOULD SWERVE TO THE LEFT. I LET THE STEERING WHEEL GO AND NOTICED THAT IT SLIGHTLY TURNED TO THE LEFT. I ALSO EXPERIENCED A VIBRATION ON THE STEERING WHEEL AND REST OF THE CAR AS I BRAKED AT SPEED OF 60- 65 MPH. I ALSO NOTICED THAT AT HIGH TRAFFIC TIMES IN STOP AND GO SITUATIONS MY VEHICLE WOULD TURN COMPLETELY TO THE LEFT AS I WOULD LET THE STEERING WHEEL GO.
I TOOK THE VEHICLE TO THE DEALER AND THEY RECOMMENDED ANOTHER ALLIGNMENT, BALANCE AND ROTOR REPLACEMENT.
I ALLIGNED THE VEHICLE AND BALANCE THE TIRES, I DID NOT REPLACE THE ROTORS. NOTHING CHANGED. THE PROBLEM IS STILL THERE. I AM THINKING OF REPLACING THE ROTORS SOON TO SEE IF IT CORRECTS THE VIBRATION. I AM WONDERING IF THERE IS ANOTHER PART IN THE FRONT END THAT MIGHT OF GOTTEN DAMAGED THAT COULD CAUSE THE VEHICLE TO TURN LEFT. I NEED HELP. WHAT DO YOU THINK I SHOULD DO. I

Sounds like the float pins on the calipers. Remove the wheels, remove the floats pins(one on top on the caliper and one on the bottom) wire wheel if they are still in descent shape(if not buy new ones) grease them up, and install back into the calipers. Might aswell do all four corners. Doesn't take long.

i have that same problem when ever i turn slowly there is a thumping in my legacy b4 1999 twinturbo