My wife started her 94 z28 today and the starter whinned and then made an awful noise.Nose had cracked. Replaced it when I got home and after cranking for a minute, the new starter cracked as well. What are some of the things I need to look for, is it timing belt, spark plugs, etc. I'm at a loss.
Thanks
Mike

 

You need to look at the starter and flywheel/flex plate. Pull the bottom cover off and look for damaged teeth. The starterpinion gear and the flywheel gear must have the proper clearance and alignment or bad things can happen. The other possibility is that thecrankshaftcannot be spun and causing the starter to break. Try turning the front pulley clockwise with a socket and breaker bar on the center bolt.

 

Try getting some new bolts for the starter. Im having the same problem with my 94z28, i havnt had a chance to work on it yet. My theory is that the starter bolts werent tight enough and that let the starter shift just enough under load causing the housing to crack and under the stress of the housing cracking it probably also bent the bolts so even if you tighten them up like they should be, it will still have a slight bit of misalignment causing it to continue to bind.

 

Check stareter alignment & shim if necesary.

Starter noise during cranking and after the engine fires is often a result of too much or too little distance between the starter pinion gear and the flywheel. A high pitched whine during cranking (before the engine fires) can be caused by the pinion and flywheel being too far apart. Likewise, a whine after the engine starts (as the key is released) is often a result of the pinion-flywheel relationship being too close. In both cases flywheel or starter damage can occur. Shims are available in 0.015 in. (0.4mm) sizes to properly adjust the starter on its mount. You will also need a flywheel turning tool, available at most auto parts stores or from any auto tool store or salesperson.
If your vehicle's starter emits the above noises, follow the shimming procedure:
[*]
Disconnect the negative battery cable. [*]
Remove the flywheel inspection cover on the bottom of the bellhousing. [*]
Using the flywheel turning tool, turn the flywheel and examine the flywheel teeth. If damage is evident, the flywheel should be replaced. [*]
Insert a suitable prybar into the small hole in the bottom of the starter and move the starter pinion and clutch assembly so the pinion and flywheel teeth mesh. If necessary, rotate the flywheel so that a pinion tooth is directly in the center of the two flywheel teeth and on the centerline of the two gears, as shown in the accompanying illustration. [*]
Check the pinion-to-flywheel clearance by using a 0.020 in. (0.5mm) wire gauge (a spark plug wire gauge may work here, or you can make your own). Make sure you center the pinion tooth between the flywheel teeth and the gauge, NOT in the corners, as you may get a false reading. If the clearance is under this minimum, shim the starter away from the flywheel by adding shim(s) one at a time to the starter mount. Check clearance after adding each shim. [*]
If the clearance is a good deal over 0.020 in. (0.5mm), in the vicinity of 0.050 in. (1.27mm) plus, shim the starter toward the flywheel. Broken or severely mangled flywheel teeth are also a good indicator that the clearance here is too great. Shimming the starter toward the flywheel is done by adding shims to the outboard starter mounting pad only. Check the clearance after each shim is added. A shim of 0.015 in. (0.4mm) at this location will decrease the clearance about 0.010 in. (0.25mm). [/ol]