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the wisdom bank
02-21-2010, 09:00 AM
I have a 1997 gmc jimmy. I had a problem when starting it. When I started it, it made a really bad grinding noise and seemed as if a tooth or some teeth on the flywheel broke off. Is this a common issue, or is there something else wrong with it that would cause it to do something similar to what it is doing? Right now, im thinkin that it needs a new flywheel from the way that it sounds when starting. It makes a loud clack noise and shackes violentely.

Molson02536
02-21-2010, 11:58 AM
I have a 1997 gmc jimmy. I had a problem when starting it. When I started it, it made a really bad grinding noise and seemed as if a tooth or some teeth on the flywheel broke off. Is this a common issue, or is there something else wrong with it that would cause it to do something similar to what it is doing? Right now, im thinkin that it needs a new flywheel from the way that it sounds when starting. It makes a loud clack noise and shackes violentely.

You may be lucky and that the starter gear has gone bad instead of the flywheel. The flywheel ring gear is harder then the starter gear on the starter, start with inspecting the starter first before you go and start investing on something that you may not need to replace. :D Good luck and keep us posted.

Here is some info,hope it helps!

Four Wheel Drive

Disconnect the negative battery cable.
In some cases it may be easier to access the starter motor bolts if you raise the vehicle, support it with jackstands and remove the wheel assembly.
Remove the starter-to-engine bolts and support the starter.
Rotate the starter as necessary for access, then tag and disconnect the solenoid wiring.

Carefully lower the starter and shims (if equipped) from the vehicle. Note the location of any shims for installation purposes.
If necessary, remove the shield from the starter assembly.

To install:
Raise the starter into position in the vehicle along with any shims (making sure they are in their original positions), then tighten the mounting bolts to 32 ft. lbs. (43 Nm).
If removed, install the shield to the starter assembly and tighten the retaining nuts to 106 inch lbs. (12 Nm).
Engage the wiring to the solenoid as noted during removal.
If removed for access, install the wheel assembly.
Connect the negative battery cable.

SHIMMING THE STARTER
Starter noise during cranking and after the engine fires is often a result of too much or tool 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 damage can occur. Shims are available in various sizes to properly adjust the starter on its mount.

In order to check and adjust the shims, you will also need a flywheel turning tool, available at most auto parts stores or from any auto tool store or salesperson.

If your car's starter emits the above noises, follow the shimming procedure below:
Disconnect the negative battery cable.
Raise and support the vehicle safely using jackstands.
Remove the torque converter/flywheel cover from the bottom of the bell housing.
Using the flywheel turning tool, turn the flywheel and examine the flywheel teeth. If damage is evident, the flywheel should be replaced.
Most starters are equipped with an access hole in which a small screwdriver or prybar may be inserted to push the starter pinion outward into contact with the flywheel.

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.

Normal pinion-to-flywheel clearance is about 0.01-0.06 in. (0.5-1.5mm).
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 0.04 in. (1mm) shims one at a time to the starter mount. Check clearance after adding each shim, but do not use more than 2 shims.

If the clearance is over 0.060 in. (1.5mm), shim the starter towards the flywheel. Broken or severely mangled flywheel teeth are also a good indicator that the clearance here is too great. Shimming the starter towards the flywheel is done by adding shims to the outboard starter mounting pad only. Check the clearance after each shim is added. Add 0.013 in. (0.33mm) shims at this location, one at a time, but do NOT add a total of more than 4 shims. :eek: