Could be the Gear syncro's thats what is sounds like to me.
Not sure how the clutch is but if you are going to have a shop do it anyway maby a good look into th tranny and Clutch. Crapy clutch fluid can cause problems too, bad clutch master cylinder.
Depending on what need to be done it could cost you. Pulling the tranny rebulding it and replacing the clutch and related parts can bring it up to a few grand.

 

My '01 Z06 did that about 5 years ago and it only had about 25k miles. Immediately I thought about the synchros going bad. I ended up taking my Z to the dealership and had the tranny fluid replaced with Dexron synthetic. It was a relatively cheap fix but if it didn't work, then I would consider replacing the synchros. The grinding problem went away and never had that problem since. I just traded my Z with 61k miles and the tranny did not grind.

 

I had the warranty work performed for the steering column lock issue in mid August this year and had the dealer do a full transmission service at that time. The transmission did shift a little smoother after that. I did miss shift and grind the gears 3 times since then and recently within the past week or two I tried pulling it into 4th driving easy with the clutch in and it grinded and wouldn't go in until I shifted to 3rd and then back down. I've now noticed that 2, 3, and 4 will all periodically have a slight grind in them within the last two days. Can synchros really go bad that quickly?

 

The likelihood of all three synchros going bad at the same time is very slim. Maybe it's your clutch that isn't disengaging very well. Have you checked the clutch fluid resorvoir? If it looks pretty dark, you might want to change it. Someone once posted a simple way of changing it out using a turkey baster to suction out all of the fluid in the reservoir. Then just fill it back up with fresh DOT 3 brake fluid.

 

Might just be a bad part who knows it was just that the symptoms sounded to me like they are going.
Does it feal like the Clutch is working right to you ? If it feels like the clutch is working good ( good pedal) then your symptoms sound like syncro's just my thoughts.
The guy befor you could have beat the crap out of it

 

Hell try another service.
Are you going to do the Work? the reason I ask is because if not your taking it to shop anyway right. They migt explore some other options that that I'm not thinking of.

 

Sorry it's taken a while to respond, thanks for your comments. I was at work when I posted the initial responses and drove the vette there. When I drove I made sure to push the clutch in all the way and wait a brief moment before shifting into each gear. It seemed to shift fine that way and it seems that there is a slight delay between depressing the clutch and the rpms dropping. To confirm what jakered said, this is my first manual car and I had a very short drive in an 02z so I can't compare it to much. My car does have an 07 z06 shifter as well. I was going to do the clutch fluid change tomorrow since it was dark when I got home tonight. I planned on following Ranger's protocol to change the fluid and hope for the best. How much would getting the synchros fixed and/or upgrading parts of the tranny cost in case this doesn't get solved? Thanks again for all your help.

 

I got the super dot 3 from gm its like 9 bucks for 8 oz( I bought 2 cans). I would change it a cupple times run it a cupple time and and change it till its fairly cleen looking. Might take you a bit to get it.
I hope that fixes your problem. after that like I said befor you might have to change your Clutch master cylinder your clutch and then the internals I think I jumped the gun on the syncros and I hope thats not the problem. but cash wise they have to pull the tranny and have a to replace what parts are messed up I think it could be 2 to 3 grand I always guess high to be prepaired because if its less then your happy.

To me now that you explain how its working it makes sence that the clutch engagement just needs a little help. If a syncro was out it would just do it all the time.
Lets hope the fluid change does it. Fingers Crossed ( I think I will)

 

I checked the fluid and it's quite dark. Tonight I'm gonna go and change it 2 or 3 times and then again next week. The pedal feels normal but again the fluid is real dark so it needs changing. Is it possible there is an issue with it even if the pedal seems to operate normally? I don't have anything to compare to so maybe there is something wrong with it. I'm just hoping that I'll be able to drive it to Albany this weekend and avoid some costly repairs.

 

Park the car on a flat surface, push in the clutch, and put the car in 1st gear. Keep your foot on the clutch. Does the car move? Your clutch isn't disengaging fully. Put the car in neutral, remove your foot from the clutch, gently push the stick towards 1st gear until you start to meet strong resistance. Does the car move? Your 1st gear syncro is fine. Repeat for other gears.

Not to be "Chicken Little", but... When a gearbox misbehaves, changing fluid can often restore some degree of operation, but usually it's just delaying the inevitable. Once something's reached wear out, it only gets worse and usually does at an accelerated pace. My 02 gearbox started to misbehave (didn't like to go in to 1st gear), and I did the fluid thing but it was only a temporary improvement. Ultimately, it was replaced.

 

With those miles and not knowing how the car was run/raced it could be either clutch or syncro wear or both.

Bad or abusive shifting can toast clutch/syncro in one session.

Before you jump to any conclusion do ALL the following.

1) Shifter alignment

2) Change tranny fluid (I use Redline d4atf)

3) Clutch fluid UPGRADE, use Ranger method & buy a HIGH TEMP fluid (I use Wilwood 570) not some crap from a local parts store.

Do all those & get used to shifting the car, tranny like engine needs to warm up a little b4 you get on it. These trannies do not "slip into gear" like a Corolla.

You can do all that yourself, use the search function of the forum, it's all there.

Post back.

:yeadog:

PS What Rocketsled posted is a good test he's spot on about stuff wearing out.

 

I am going to try the flat parking lot tests hopefully this weekend. I think that I should also figure out how adjust the shifter cause it has a new z06 shifter which might not be going in properly although I can't see how that would cause grinding. Is there a reason why everything seems normal when I come down in gears, never does anything wrong when I downshift. I'm fearing the worst but hoping for the best on this one.

 

If your shifter doesn't have enough throw, it could result in grinding if the gears aren't being pushed far enough to fully engage.

Though if you have no trouble downshifting, only upshifting, that suggests too much end-play somewhere in the gearbox.

 

So I tried pushing the car into gear on a flat surface and it does push the car forward. I did discover that even with the clutch fully pushed, I can't pull the shifter into 4th quickly (hard) without there being grinding. Third seems to be okay doing that and second balks a little bit. I think I'm gonna try putting the original shifter back on and seeing how that works and/or try adjusting this shifter and seeing if that helps anything. If this doesn't help, it looks like I'll have to have someone look at it. Kinda frustrating but o well, it's a risk you take.

 

Best of luck keep posting, Keep us updated. This is the kind of problem that we would like to find the outcome too.

 

I just recently bought a 01 Z06 and the grinding problem is occuring with mine going into 2nd gear (mainly when I'm hammering the throttle) and I'm not missing the shift. The problem doesn't occur at low speeds (being driven normally) The clutch feels fine, but I'm really just at a loss. I usually just start in second gear or skip it all together now, but would like to get complete use of my tranny. Anybody think changing the fluid will help??? I really hope its not the synchros going out, I don't feel like footing that bill

 

You can try changing the fluids, but based upon my past experience with my '02, it's gonna be the syncro :yeadog:

Mike

 

Go back & review the whole thread, read my post #13, do all that stuff, it's not very hard to DIY or with a friend. It MAY help enough so you can get by for a while.

It may also be that the previous owner(s) toasted 2nd gear syncros with bad shift(s).

But do all that easy & cheap & quick stuff first.

 

I apologize for the slow response, I've recently moved and haven't gotten the internet hooked up at my place yet. I haven't had a chance to make any changes to the car or change the clutch fluid again. I did it three times the first day and it needs it again but the weather has been shitty and I've been busy, both culminating in no work being done. My dad drove the car this past weekend and confirmed that I'm not crazy, he was getting some grinding as well. I'm hoping this weekend I will get a chance to change the fluid again and re-install the factory shifter to see if it's an alignment problem. I think I'm going to call the chevy dealer that just serviced the transmission since I didn't notice any grinding before they did that and see if they have any opinions. From what it sounds like though, the synchros are probably the issue. I sure hope not but I want to first eliminate the cheap stuff. Another thing to note, my shifter doesn't have a very strong centering action to it, not sure if that's normal or not. Thanks

 

I highly recommend you put back the stock shifter before going to the dealership. My experience when I took my Z to the dealership about the 2nd-gear grind was that they immediately started to point the finger towards the Hurst short-throw shifter that I installed. Fortunately for me, the tranny fluid change to synthetic took care of that problem.

 

In a proper working stock shifter there is a strong centering effect.

It centers on the 2/4 of course.

There is a mod called anti venom that lessens the effort to move the shifter from neutral position to any of the gears.

Some like it, personally I never saw the point.

Could be previous owner did something along those lines & messed it up?

Good luck.

 

I realize this post is kinda old and dated but I have an update on the grinding issues that I've had. This past summer I finally got the chance to pull apart the console and get at the shifter. I decided to start by loosening all the bolts and then tightening them all back to spec. This illuminated one of the bolts being stripped and not capable of being torqued to 22 lbs. but I was able to get about 16 lbs. and decided to see what happened. After doing this, the shifter had normal centering force finally and did have much more pronounced gates plus I could finally get it into first without going into second then up (most of the time). Although it was much improved, there was still a grind going into some of the gears. I then tried lining the shifter up as best I could (without getting the alignment pin all the way down) and again, improved but still some grind. Today I was able to get the alignment pin down and tried lining it up as best I could. It was improved, but still catches on something going up in some of the gears and not all of the time. It's very weird that coming down 5-4-3 is usually better than going up. Any idea? I'm guessing that I'll probably have to try installing the original shifter back in or maybe the hurst that I also have but I'm not sure if this is a shifter problem. Thanks for your help.

 

From my personal experience....its just a matter of time. However, start cheap first, like you have done...shifter alignment...fluid change....if it keeps happening, its time to yank the trans.
This can be done on jacks in your garage if you are mechanically inclined. I have done it twice, took about 6-7 hours to get it out, and 8 to put the new trans in.
Also, when the time comes....and this is just my personal opinion, get a good trans shop to rebuild the entire trans....meaning do NOT let a dealer shop do it and dont "just" replace a worn synchro or two...guaranteed the worn synchros caused other parts to wear also.
I had Rockland Standard Gear do mine after the RPM Stage 5 I paid good money for started crapping the bed and they would not stand behind their product.

 

Yeah, that's the approach I'm taking at the moment try to get each thing right and work my way to each component. I might as well elaborate on the shifting to better describe it, the "catch" that I'm feeling doesn't really matter whether I'm moving or not. The (luckily) now occasional trouble getting into first obviously happens when stopped. I can feel the "nick" going into 4th and 3rd with the car stopped and moving. After carefully trying to align the shifter yesterday, there definitely seems to an improvement (read: more normal shifts) and the shifting does get better as the tranny gets warmer. Still trying to figure what could be causing the problem but I have 2 more shifters that I'll end up trying in the coming weeks as I get around to swapping them in. If you don't mind my asking how much would a full transmission fix run me? My thoughts are if I'm going to tear into the transmission I'd want to spend the money and have it made to "not" break.

 

I've had grinding problems on a two previous transmissions due to high RPM shifts from 2 to 3. The grinding just got worse over time. Once the tranny was apart, all the gears were worn down. I would start saving to rebuild the transmission with upgraded parts.