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Old 12-06-2012, 11:03 PM   #1
M///Scooby
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Default 5th gear grinding issue, anyone else - 2012?

So here is my issue (2012 WRX hatch). When cruising along around 70-80mph and put the car into neutral, let he RPMs drop to idle RPM, then try to put it in 5th gear, the gear grinds. It happens all of the time when doing this.

So I take the car into the dealership today, explained the issue and took a service tech for a test drive to replicate the issue. He thought it was odd and nothing came to mind. I thought it was the synchro, but it would do it all of the time. Going from 4th to 5th while getting up to speed is not a problem also.

Well I get a call saying they did my 7500 mile service (car has 7,900 miles) and that they could not find anything wrong with the car after speaking to the regional rep and what not. I was not okay with this as there is clearly something wrong.


SO tomorrow they are going to call the national tech office (or something like that) and see if any other car has had this issue.

So my question here is, has anyone experienced this is their car? What might this be? Software issue?
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Old 12-07-2012, 12:09 AM   #2
turbolvrwrx
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Why would you want to let it drop to idle before shifting into 5th? I can't see a "software issue" causing gears to grind.
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Old 12-07-2012, 12:14 AM   #3
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as asked above, why let your car drop to 'idle' to shift into 5th ? Does it shift fine into 5th when upshifting like normal?
The first fix that comes to my mind, is shift like you are suppose to.

Also, in no way would 'software' (i'm assuming you mean your ECU) cause a mechanical grind during an upshift.
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Old 12-07-2012, 06:31 AM   #4
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We haven't had anything like this with our WRX, and I haven't heard of much like this with WRXs as a whole. I have experienced various similar-sounding issues with others cars.

What happens if you rev-match the return to 5th gear? What happens if you double-clutch the return to 5th gear? Is it different with lateral load to the left? To the right?

Shifter forks for gears must be in proper alignment to avoid grinding and for the gears to mesh well. I've never heard of an alignment issue with the shifter forks on a WRX, but that doesn't mean it's impossible. I have heard of alignment issues with the 3/4 shifter fork on third gen Miatas, and it'll cause the related gears (most often 4th in that car) to give a bit of a grind engaging the gear from time to time. Putting lateral load on the car (cornering hard) will cause parts to move in relation to one-another, which can either make it worse or better (or have no impact) depending on the specific way the alignment is off. That's the motivation behind the lateral load questions.

Rev-matching the shift gives the synchro less work to do - it helps spin up the appropriate shafts as needed. Doubleclutching eliminates the need for the synchro all together - before transmissions had synchros, double-clutching was needed to downshift (or go into a gear at 3,000 rpm from idle) without grinding. If the shift grinds consistently just putting it into 5th, but never grinds with a proper double-clutch, there is most likely something wrong related to the synchro. What? Dunno. That would need even more diagnosis.
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Old 12-07-2012, 06:36 AM   #5
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Quote:
Originally Posted by M///Scooby View Post
SO tomorrow they are going to call the national tech office (or something like that) and see if any other car has had this issue.
No they're not.
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Old 12-07-2012, 07:36 AM   #6
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Quote:
Originally Posted by saar View Post
as asked above, why let your car drop to 'idle' to shift into 5th ? Does it shift fine into 5th when upshifting like normal?
The first fix that comes to my mind, is shift like you are suppose to.

Also, in no way would 'software' (i'm assuming you mean your ECU) cause a mechanical grind during an upshift.
Agreed, it's driver error.
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Old 12-07-2012, 07:40 AM   #7
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If this was caused by driver error, it would be something like not fully depressing the clutch. Whether or not it's "appropriate" to shift to neutral and let the revs drop while going 80mph, it should be something the mechanical aspects of the car can handle without problem.

In other words, the cause of the grinding is not "driver error" just because of a shift to neutral. The appropriateness of shifting to neutral is a separate concern. The gears should not be grinding on this shift, assuming the clutch is fully depressed.
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Old 12-07-2012, 09:22 AM   #8
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I guess I was not clear in my post of why I go to neutral. I have hills where I live so when on the freeway going down a hill, I throw it into neutral to coast down the hill, thats why the RPMS drop to idle speeds. At that point when I try to put it into 5th, the gears grind. I have tried rev matching and it does not work. double clutching does not work. It does into to 4th fine, but not 5th.

I hope this clears up a few things.

Also, it is NOT driver error, if it was, all my gears would be grinding

Also, is there a computer that monitors the transmission or anything with these cars. When the service person told me it might be software, I asked how on a MANUAL!?

Anyways, There is a problem and they seem to not know or want to deal with it.
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Old 12-07-2012, 09:37 AM   #9
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Why coast down the hills? It's not like you are saving any gas by doing that.
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Old 12-07-2012, 09:47 AM   #10
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Why coast down the hills? It's not like you are saving any gas by doing that.
Why not? Why keep the rpms at 3k going down a hill and just coast? Either way, thats what I do.
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Old 12-07-2012, 10:23 AM   #11
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Quote:
Originally Posted by M///Scooby

Why not? Why keep the rpms at 3k going down a hill and just coast? Either way, thats what I do.
When coasting in gear you're not using any fuel. Also if you left it in gear you wouldn't have any grinding problem to begin with.
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Old 12-07-2012, 10:25 AM   #12
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Quote:
Originally Posted by M///Scooby View Post
Why not? Why keep the rpms at 3k going down a hill and just coast? Either way, thats what I do.
Because at 3k rpm your engine is turning with the injectors (effectively) off. You are saving more gas by coasting in gear than you are by coasting in neutral. Many threads on this, I suggest searching.
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Old 12-07-2012, 10:33 AM   #13
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Many vehicles will do this..don't coast from high speed and they try and put it back in 5th as it will most likely grind. You are chewing up your tranny trying to save a few cents.
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Old 12-07-2012, 10:42 AM   #14
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Who said anything about saving gas, where in my post did I say I do this to save gas? Reality is, lots of people do this, in my Audi A4 I did this with zero issue, I do that in my BMW, zero issues.

Regardless, apparently no one here has experienced this issue or knows anything about it.
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Old 12-07-2012, 11:13 AM   #15
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No issues going into 5th, have the issue you're describing going into reverse if I pop it out then try to put it back in (that's what she said) without releasing the clutch... but that's because of the square cuts.

Oh, and while you didn't talk about wasting gas, but others are suggesting that people probably don't see your issue because they leave it in gear when coasting due to local laws, sounds, and the injectors turning off for 0 fuel use. Just saying...
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Old 12-07-2012, 11:25 AM   #16
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Thanks for that response. I appreciate you being curtious and rude saying I can't drive.
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Old 12-07-2012, 11:27 AM   #17
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Quote:
Originally Posted by nightdown fox View Post
No issues going into 5th, have the issue you're describing going into reverse if I pop it out then try to put it back in (that's what she said) without releasing the clutch... but that's because of the square cuts.

Oh, and while you didn't talk about wasting gas, but others are suggesting that people probably don't see your issue because they leave it in gear when coasting due to local laws, sounds, and the injectors turning off for 0 fuel use. Just saying...
Exactly, there is no good reason to do this so most manual drivers don't and therefore will never experience this exact issue.
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Old 12-07-2012, 11:35 AM   #18
M///Scooby
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Look I'm not going to argue about the coasting thing. Fact is, a lot of people do this. That's here nor there. There is any issue and I was turning to the forums for assistance. Clearly this forum is not the place to go for assistance.
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Old 12-07-2012, 11:54 AM   #19
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I coasted until I grinded gears also, that's 100% why you're having this problem, rev matching and what not. You're obviously not at the right speed/rev for it to shift smoothly, however I'm in an sti
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Old 12-07-2012, 12:02 PM   #20
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Quote:
Originally Posted by M///Scooby View Post
Look I'm not going to argue about the coasting thing. Fact is, a lot of people do this. That's here nor there. There is any issue and I was turning to the forums for assistance. Clearly this forum is not the place to go for assistance.
I have never heard of anyone doing this. It doesn't even make sense in any front. You don't save gas, you don't gain much extra speed, and it is obviously hard on your driveteain
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Old 12-07-2012, 12:10 PM   #21
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How is it hard on your drivetrain to coast down a hill in neutral?

Anyways this is pointless.
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Old 12-07-2012, 12:16 PM   #22
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So if you're coasting and put it into fourth from neutral, you can then shift into fifth fine?
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Old 12-07-2012, 12:20 PM   #23
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So if you're coasting and put it into fourth from neutral, you can then shift into fifth fine?
Aaaaa
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Old 12-07-2012, 12:28 PM   #24
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My commute has like a 15 mile stretch of 6-8% grade downhill, so I would do this a lot! It gives ridiculously better gas mileage to be in neutral as opposed to coasting in gear (3mpg round trip 100 miles). And it was daily for a long time, so very easy to be regular and monitor it. I used to pride myself on only having to touch the brakes three times on that commute only when coming to a complete stop.

I noticed the same issue in my 08 impreza, and I started shifting into 4th, and then straight into 5th without releasing the clutch and it worked for probably 6 months. 10k miles later it started grinding going into 4th, but 5th was smooth. It changed...

When I got my 09 WRX, basically the same with 5th gear. I started getting better at rev matching, and now I don't have the problem. I am not sure if one was easier than the other at avoiding the grinding, but rev matching is always a good thing in this situation.
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Old 12-07-2012, 12:34 PM   #25
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Quote:
Originally Posted by chet24 View Post
My commute has like a 15 mile stretch of 6-8% grade downhill, so I would do this a lot! It gives ridiculously better gas mileage to be in neutral as opposed to coasting in gear (3mpg round trip 100 miles). And it was daily for a long time, so very easy to be regular and monitor it. I used to pride myself on only having to touch the brakes three times on that commute only when coming to a complete stop.

I noticed the same issue in my 08 impreza, and I started shifting into 4th, and then straight into 5th without releasing the clutch and it worked for probably 6 months. 10k miles later it started grinding going into 4th, but 5th was smooth. It changed...

When I got my 09 WRX, basically the same with 5th gear. I started getting better at rev matching, and now I don't have the problem. I am not sure if one was easier than the other at avoiding the grinding, but rev matching is always a good thing in this situation.
Thank you!

I do rev match when downshifting. My only option tv this point is to see what the dealership says.
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