I have got a 97 z28 that just the other day started shifting hard.
I mean it shifted fine on the way to work I could shift easily into any gear. Now it takes a lot of pressure and makes a whirling sound. I have just started to syncro shift and not use the clutch when I have to drive it. Even at a stop light It doesn't like to go into first easily like it did before. Has anyone one had this problem and how do I fix it.

 

Check the fluid level in the clutch master cylinder reservoir?

Is the trans filled to the correct level with Dexron-III ATF?

 

Fluid is good on the master cylinder, it was almost empty when I bought it 1200 miles ago. I checked the trans and it has clean red fluid in it at the upper point to check it don"t know what type. It supposedly had a clutch put in it a year ago and hasn't had that many miles on it. they told me this after I had already paid them so I hope it's the truth. the clutch feels solid. would it do me any good to pull the shifter and check the ball on the end.

 

I doubt the shifter would be the issue.
If the clutch master cylinder was low when you got the car I'd suspect a leaking master or slave cylinder. I'd go under the car and take a look for leakage at the slave cylinder.
Also, see if you can pin down the "whirling noise" you spoke of. If it's synchros going bad it should show up when you're trying to select a gear that requires the synchro "works hard" to get that gear to the correct speed. However, it could also be the throw out bearing starting to go bad and the drag/friction will cause the tranny to be hard to go into gear. A bad throw out bearing will exhibit different noises depending on how much pressure is on the clutch pedal. No pressure is usually the noisiest since the throw out bearing is unloaded.
good luck

 

How did you bleed the clutch hydraulics after you filled the master cylinder reservoir? No bleeder provided.

Sounds like the clutch simply isn't releasing.

 

The clutch never stopped working when the reservoir was empty I simply filled and drove. Since then I have bled it with a mighty vac from the top but there wasn't much if any air coming out. Now the clutch will only releases enough with the engine shut off so I haven't been driving it. Talked to a few mechanics and I think I'll replace the master cylinder the slave doesn't appear to be leaking and i haven't lost any fluid since I had filled it. The car had been in storage for most of the last year and had sat dormant for a couple before that. Hope it works if not I guess i'll dig deeper.