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1st gear grinding HELP

Old 10-24-2014, 09:50 PM
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gdmiller123
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Default 1st gear grinding HELP

Im sorry if this has been covered but ive googled the crap out of this but can't find anyone that's had this exact problem so here we go...

if the car is at idle and you push the clutch in and imidiatly try to go into first it will grind

If your at idle and push the clutch in for 5-10 seconds it will go into first just fine

It will go into all other gears just fine with both methods as above

If you try to gear down to first while rolling it will grind

It has never done this before. I did replace the transmission fluid with regular dextron III advance auto brand about 400 miles or so before this issue started

The car is a 2003 Z06
Twin dick clutch, C6 shifter, stock master and slave from what I can tell other than it has a remote bleeder. I did flush the clutch fluid until clear and it had no effect on this issue. I also did the shifter alignment procedure as well as put a stock c5 shifter back in and the problem still existed.

Would a Tick Master cylinder fix this issue or is it a synchro issue?

Last edited by gdmiller123; 10-24-2014 at 09:52 PM.
Old 10-24-2014, 10:02 PM
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martysauto
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Sounds like your 1st gear synchro is bad. If you push down the clutch and immediately shift to 2,3,4,5, or 6th gear and it goes in with no problem, it's the synchro.
Does your car creep forward in gear with the clutch pedal depressed?
Old 10-24-2014, 10:38 PM
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Bill Curlee
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I agree..

Why are you down shifting into 1st????

Ive done it just to do it but, theres really NO reason to down shift into first. It really puts a load on that synchro when you do it.

Its there so you can smoothly get back into first at very low speeds.

Bill
Old 10-25-2014, 12:34 AM
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Russell Boulding
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Originally Posted by gdmiller123
Im sorry if this has been covered but ive googled the crap out of this but can't find anyone that's had this exact problem so here we go...

if the car is at idle and you push the clutch in and imidiatly try to go into first it will grind

If your at idle and push the clutch in for 5-10 seconds it will go into first just fine

It will go into all other gears just fine with both methods as above

If you try to gear down to first while rolling it will grind

It has never done this before. I did replace the transmission fluid with regular dextron III advance auto brand about 400 miles or so before this issue started

The car is a 2003 Z06
Twin dick clutch, C6 shifter, stock master and slave from what I can tell other than it has a remote bleeder. I did flush the clutch fluid until clear and it had no effect on this issue. I also did the shifter alignment procedure as well as put a stock c5 shifter back in and the problem still existed.

Would a Tick Master cylinder fix this issue or is it a synchro issue?
To echo the others its sounds like a synchro issue. The reason it works fine after 5-10 seconds is that the input shaft has slowed down enough or stopped completely and now the speed of the input shaft and output shaft are close enough or matched so the synchro has nothing to do.
Old 10-25-2014, 01:05 AM
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gdmiller123
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Originally Posted by Bill Curlee
I agree..

Why are you down shifting into 1st????

Ive done it just to do it but, theres really NO reason to down shift into first. It really puts a load on that synchro when you do it.

Its there so you can smoothly get back into first at very low speeds.

Bill
I don't down shift into first like your thinking. More like if im pulling into a parking lot from a main road when i get to around 10mph ill go and put it in first in anticipation for the slower speeds with the clutch still in.
Old 10-25-2014, 01:46 AM
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Bill Curlee
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Originally Posted by gdmiller123
I don't down shift into first like your thinking. More like if im pulling into a parking lot from a main road when i get to around 10mph ill go and put it in first in anticipation for the slower speeds with the clutch still in.

Thats EXACTLY what its designed for... You have a bad synchro cone.. Unfortunately,, that requires a complete tear down..
Old 10-25-2014, 02:16 AM
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Z06ster
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Originally Posted by Bill Curlee
. .. You have a bad synchro cone.. Unfortunately,, that requires a complete tear down..
It is a sad reality but the C5 Transmission doesn't have longevity. I had the same exact thing happen to me. At a mere 55,000 miles on the car, first gear started grinding. I ended up getting an RPM transmission.

Let us know how it turns out.
Old 10-25-2014, 06:30 AM
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strand rider
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That made me laugh, a big thumbs up smiley face, and ....... you need a a full rebuild.

I clicked in just to learn something, but couldn't resist that one.

I have the same tranny, so your road is mine, you are just further along. I am hoping to reach the 120, 000 mile service interval on the trans bearing replacement, but things are already requiring a little finesse on anything except take off.

In reading this post , I now think that some of my questions about wear have been quieted, thanks .
Old 10-25-2014, 10:11 AM
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Originally Posted by Z06ster
It is a sad reality but the C5 Transmission doesn't have longevity. I had the same exact thing happen to me. At a mere 55,000 miles on the car, first gear started grinding. I ended up getting an RPM transmission.

Let us know how it turns out.
Ill likely leave it as is until it gets worse. Thankfully its first so its easy to drive around it.
Old 10-25-2014, 01:13 PM
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Originally Posted by gdmiller123
Ill likely leave it as is until it gets worse. Thankfully its first so its easy to drive around it.
Yep... that's what I did. I don't know if this applies to your case but when this happened to me, I found if I first threw the shifter in the second gear position, I could then go into first without grind.

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