TomTarzian

I thought this was behind me after about 1,200 miles, as it didn't happen for the next 500 or so. Had the motor and tranny/diff oils changed last week at 1,800 miles. On my first drive since getting it back I got the 1>2 grind on a very easy, low rpm shift. The several earlier grinds were at high rpms--over 5,000, if I recall correctly--and now this one at low rpms. I'm beginning to think there is something wrong with the tranny or the clutch.

God bless,
TT

MannyLon

Does this happen if people select 2nd very quickly?

TomTarzian

In my case, both quickly and not quickly. It just comes out of the blue, without any "driver error" warning.

God bless,
TT

Jimmycrack

It happened to me as the lever was entering 2nd even from neutral when I tried double-clutch downshifts. At 1k miles, it still was happening but it was less frequent and much more smoothed out and not nearly as jarring. The subsequent 1000 miles I have driven almost solely with autoblip off and haven’t experienced it since. I’m guessing that is just coincidence and more related to the break-in.

Westcoast

Tom, thanks for providing this information, but now I am in a position where the hoped cure (fluid change) may not be the answer...

JSF101

I have two 2016 GT4s. Prior to owning them I had a Boxster, Cayman S, Boxster Spyder all with manuals. Never ever had a gear grind with any of them.

Never ever had a gear grind with either GT4 until AFTER the transmission replacement campaign was done on each one.

Then, both had 1 to 2 gear grind. I read somewhere in this long thread that someone assessed adding slight throttle before completing shift might be a cause.

I really have no idea why this happens but it certainly is disconcerting. Every time it happens I question why, what did I do to cause it?

I've been very deliberate in shifting and try not to make short shifts from first gear to second. The only time I notice it is at low rpms. I haven't had it happen at higher rpm shifts, above 4000 rpm.

Since I've been driving manuals for a long time, I don't think it's how I drive because it's never happened before.

But I try to make very deliberate shifts from first to second. I have one high mileage car and one low mileage car but both had the campaign done at the same time (within a month). They both did it after the campaign.

I just returned from a short drive downtown with lots of stop and go.
Sometimes the shift seems very smooth and normal. Other times it feels a little labored (tight) and not as smooth.

that's all I know

unclemat

^ Interesting.

Looks like Getrag changed something to address the vaporizing 3rd gear, and screwed up 1-2 shift in the process.

To think that synchronized manual transmissions are nearly 100-year old technology...

Nickshu

I am at 1600 miles and one track day, still having the 1-2 grind, but less often. I do not think I am applying the gas or letting the clutch out before completing the shift. Have been to dealer once for it, they said everything checked out normal. Car needs to go back in for a different warranty issue they are fixing (awaiting part), will ask them to change transmission oil when it goes back in. Not that it will probably make any difference, but will document escalating attempts to address it in the warranty file in case something happens in the future.

TomTarzian

Sorry to be the bearer of bad news, WC. I was hoping fluid change would cure it, too. Haven't had a grind since that first drive on Saturday, though...to be fair, I've probably only had five grinds in total. Four before fluid change (from 1,100 miles to 1,200 miles) and one since. No grinds from 1,200 miles to 1,700 miles, when fluids were changed. I think there's hope but not sure why, other than I'm a glass half full kind of guy. This car is just so much fun to drive, maybe there has to be one little fly in the ointment?

God bless,
TT

Spyder8286

I had it happen once again yesterday. I'm starting to think it's my feet moving a tiny bit faster than my hand. Meaning, as I'm going into second, but not yet fully in, I'm starting to come off the clutch and get back on the gas. The clutch is barely off the floor and I'm barely on the gas and I feel like I'm pretty much in second, but I think the combination of those actions together is just enough to cause the grind. Conversely, if I slam the gear lever from first to second, I never get the grind. I'm thinking that's because I'm fully in second before I even start to release the clutch or touch the gas. We're talking about milliseconds, but I think that's maybe why the grind seems to be random. We all feel like our technique is the same and the grind comes without warning, but in reality there are fractional differences in that dance of lift off gas, depress clutch, change gear, release clutch, back on gas. I'm going to be very deliberate with not releasing clutch and not touching gas until I'm in second and see how it goes.

Westcoast

If the bolded were true then it is no a problem with synchro-rings...

Spyder8286

For what it is worth, I went out today at lunch and just tried a bunch of different 1-2 gears shifts. I did high rpm (6k); low rpm (just getting moving and then into 2nd); quick shifts minimizing rpm drop; super slow shifts letting rpms drop almost back to idle; coasting in neutral and then dropping into 2nd. I was careful to be hard off gas every time and not go back to gas until I was fully in 2nd. Zero grinds. Now, to really test the theory, I should have gone to the gas a few times to try to induce the grind, but I just couldn't intentionally do that to the car.

Westcoast

I am with you on testing that intentionally causes a grind to occur, I haven't had a grind for awhile but I too have avoided what I 'think' is causing the problem...

JSF101

agree with you
we autocrossed this past weekend and never had a 1-2 problem, high rpm shifting only
not going to test the reverse, doesn't make any sense

but I agree with your earlier comment that it could be just letting off the clutch a millisecond early...but that seems odd (especially after all of those years of never having had the problem
may just be lazy (slow) getting the shifter from one to two

Thinker23

Read that this transmission is made by Getrag. If thats true, it maybe that they just used same parts from transmission used in E9X M3? Similar horsepower and torque = same parts bin, same problem.

I don’t think it’s a user error. Most of the comments here remind me of M3 grinding and notchiness complaints. For whatever reason, that transmission feels significantly better after fluid change and quickly degrades.