idle vibration--in gear only (95 Legacy)

[Guest zimmee66]

hey all!

 

My 95 legacy vibrates pretty badly at idle in gear. Goes away if I pop it into neutral.

 

I know its a boxer but Im certain its a new problem so I don't think its normal.

 

A bit of history:

 

My awful dealer (White bear subaru/acura)

tried changing tranny fluid/filter

(made no sense to me-but needed it anyways so went ahead) and then said it was my brakes causing the problem, because my rotors were bent---I pointed out the problem was there at a stop too, and they said it

was because of vacuum assist.

 

Needless to say I gave up with them at that point, and now am going to try to fix it myself.

 

(On that note, anybody have a mechanic recommendation in the minneapolis area?)

 

I am going replace the fluid with synth since I hear that is helpful with rough shifts...but I dont think this will really solve the problem.

 

I think maybe I bent a driveshaft (sounds expensive!) or this is something more obscure...ideas or experiences?

 

regards

-jim

 

*** moderator edit - clarified topic for move to archives ***

[Guest SmashPDX]

May be obscure. Here's the question roster:

 

(1) Does it happen in Park or just in Drive/3/2/1 (siting at stop signs, lights)

(2) Is it an intermittent issue?

(3) When it happens, does it sometimes shake more than others?

(4) If you shift into Reverse, does it show up?

(5) If you take your foot off the brake and let the car roll forward a smidge, does the vibration 'change', i.e., get heavier, lighter, or maybe go away entirely (until at least the next stop)?

(6) Does it seem 'easier to duplicate' on uphills and/or downhills, even slight ones (like a driveway or mall parking lot entry) vs. level ground?

 

Have you figured out yet that I've run into something similar on my car?

 

Good news: If your answers match mine:

 

(1) Just in Drive/3/2/1

(2) Yes

(3) Yes

(4) No

(5) Yes

(6) Yes

 

Then we have the same problem.

 

More good news: I know the cause, there was an axle manufacture issue, caused by engine vibration transmitted through the autotranny-specific front axles into the body. The problem was known by Subie techs who were 'in the know,' and was historically fixed by replacing the autotranny-specific axles with the ones intended for the manual tranny. This was done by some dealers under the powertrain warranty. The problem didn't affect all 95 Legacies, it was more common in '96, but overall they never found a real pattern to who was going to be affected so most folks didn't know about it.

 

Thanks (again) to Mike Corbin at Smart Service in Seattle for clueing me in on this, way back when.

 

Still more good news: It's not an idle problem. Your tach may be making you think you have low idle, but did you know your tach underreports your RPM at idle on the '95 (and probably other vehicles)? Based on the smart 'puters that poked my car for its last emissions test, when my tach says about 666-700 RPM it's actually doing 1000, which is absolutely in spec. Funny huh?

 

Now the bad news: Subaru discontinued the manufacture of *both* types of axles and replaced them with a new, unified part. My dealer, in trying to resolve this issue, put the new part in my car. It was nice to get new axles with the mileage as high as it was on my car. Unfortunately, they didn't fix the problem, and since the old mantranny-specific axles aren't made anymore, we had no way to try them out.

 

Does this sound like your car? I know mine has become VERY acquainted with being shifted into neutral.

[Guest zimmee66]

WOW!

thats it...to a tee. Thank you!

 

Wish I had your dealer!

 

Is there an actual TSB on this or is it just savvy tech lore?

 

At least I know where to begin. What worries me is that

the dealer always said they "couldnt feel it" (ridiculous since even my mom can tell!) and then gives the old "boxer" excuse. Phooey.

 

But it sounds pricy, and Im hoping to trade up to a 97-ish wagon so Im afraid it will hurt resale if I dont fix it!

[Guest Suzam]

Wow, I've been putting up with the "shakes" in our '95 for years. Dealer had no clue or incentive to find out what was going on, claimed they couldn't reproduce it. Sometimes it rattles the change in the console. If the driver's window is 1/3 the way down it bangs and rattles like crazy, have to open or close it all the way. I'm so used to it I don't notice it anymore unless a new passenger remarks about it. At least I know I'm not TOTALLY crazy anymore!

 

[Guest SmashPDX]

I suspect that there is a TSB out there, but I don't know what it is. If you can get near a halfway decent Subaru Master Tech and ask about a '96 model year issue with transmitting engine vibration through the front axles that may get their attention. What will get you over the hump in terms of their understanding will be getting them to drive with you for a spell. If they understand the nature of the issue as I described it and they seem 'interested,' let them drive, because they'll know how to work to duplicate it as opposed to waiting for it to show up. If they don't understand the nature of the issue, you drive and YOU duplicate it while so they can sit there and get shaken up. It's important that you show them the diff between a 'normal' stop and a 'shaking' stop.

 

Me and the tech at my dealer drove around for a good 1/2 hour talking about it as we put the car through its paces.

 

Mike Corbin used to work at a dealership before starting up Smart Service (independent Subaru mechanic) in Seattle. He's here on the board from time to time and I recommend him highly to anyone in his area-- his rep in here is rock solid. Armed with the information he gave me I was able to go to my dealer (CARR Subaru of Beaverton), who I already had a good relationship with, and work this out with the help of an SOA regional rep. In the end I paid for the parts and they covered the labor, since I had reported the issue before the warranty expired but we were fixing after-the-fact.

 

For awhile after the change the issue seemed better but it eventually came back. BTW I replaced the motor mounts too, thinking that might help, no change.

 

The one thing I remember the master tech at the dealership telling me was that what gives this problem away (vs idle issues) is that the vibration you do or don't get is dependent upon both the direction of torque and the angle that axles are sitting at. If the car is in drive and you bring the vehicle to a stop, it pitches forward (even slightly). The original autotranny axles were a shade too long, so when you pitched forward, some of the parts in the joints that would normally have some play wind up in direct contact with each other. So you have a direct physical path for vibration to run down from engine to axle to vehicle.

 

Put the car in neutral, and you take the torque off of the axles, things loosen up, no vibration transmission. Similar thing happens when you shift it out of drive, through neutral, into reverse. Angle of attack is also an issue-- let's say you're turning into a sloped-up driveway, you put the right front wheel up on it so that the axle is 'crunched' just a shade and stop. One axle or the other is going to be more likely to get 'into position' to transmit vibration.

 

And then finally, since it's all dependent upon axle position, even rotating the wheels a little bit (letting it 'creep forward' a bit then stopping, as I described) will change the level of vibration you feel.

 

So there you go. Kind of makes sense when you think about it, but it feels like an idle problem so everyone chases it into that dead end and gives up because there's no problem to find there.

 

As far as getting an actual solution to your situation, my opinion is that there isn't one, at least not a complete one. In my conversations with the dealer I gathered that my vibration was pretty 'lightweight' compared to what they had seen on some of the '96s-- more consistent, more severe. In the end they were only able to nail my issue down because of how it behaved with respect to being in gear, angle of attack, etc.

 

With that said, you could go ahead and replace the axles if you wanted to-- but in my case it got better and then went right back to doing what it always did after the new parts settled into place.