View Full Version : My Starter is grinding (loud)when cranking!!!--any ideas??


75LTCAMARO350
10-09-2007, 11:12:47 AM
The car is a '75 LT V-8. auto.
It will start, and drive---
After like 1 second cranking it will start loud grinding noise....
someone told me to shimmer it?? Don't know what that is.

Any help would be great!! THX in advance!!

CorkyE
10-09-2007, 11:24:35 AM
Here's a couple post I caught on a quick search. If they don't help, let us know.


http://www.nastyz28.com/forum/showthread.php?t=86292&highlight=shim+starter

http://www.nastyz28.com/forum/showthread.php?t=77930&highlight=shim+starter

http://www.nastyz28.com/forum/showthread.php?t=65135&highlight=shim+starter

http://www.nastyz28.com/forum/showthread.php?t=58977&highlight=shim+starter

angel71rs
10-09-2007, 11:26:54 AM
Did it just start happening, or after a new starter install? You usually shim on install to get proper tooth engagement. Is it a grinding noise or a loud whining noise? If whining, it might be the bendix. It kicks the starter gear back. When they go bad, your starter will sometimes crank for an instant, then the bendix kicks out and the starter just free revs, so you get the whining noise.

75LTCAMARO350
10-09-2007, 12:16:06 PM
I just got the car. I don't think a new starter is in it. But I'll check.

The noise is NOT very high pitched. But it sure is a nasty grinding sounding. As soon as I hear it I let off the starter key and crank again. Just repeat until it starts.

I will get under it and see if anything loose.

68400BIRD
10-09-2007, 01:09:28 PM
Sounds like it just needs to be shimmed or it could be lose.

gordonquixote
10-09-2007, 01:15:32 PM
Sometimes over time the starter shifts some and moves away from the flywheel. Then the bendix and the flywheel don't mesh and the gears grind.

Loosen op the starter so you can easily wiggle it, pull the solenoid end of the starter away from the block (usually won't move much), and then tighten it back down. Try this before you take undertake the hassle of shims, shim it as plan B.

I had the same problem and fixed mine this way Sunday (I tried to start mine in gear and it shifted the starter).

68400BIRD
10-09-2007, 02:31:20 PM
Just as a helpful tip, you do not have to take the starter out to shim it. Look at the shims and only take out the one bolt that you need to. The other side just slides in.

75LTCAMARO350
10-10-2007, 09:59:22 AM
THANKS for the great info!! I like to start with the easy stuff first.

Should I try maybe jumping the car---to see if there is a weak battery in it causing this grinding????

The battery looks kind of new---but........
I 'll check for good connections also

68400BIRD
10-10-2007, 10:43:37 AM
A bad battery is not going to cause grinding but it could cause a slow rotation of the motor or starter that will sound real bad. If the starter is turning the motor over real fast I would not worry about the battery. Or you could have the battery load tested. If the starter is crashing into the flywheel and then turning the motor over it will give you a grinding noise. I would get a pack of shims out of the help section and install one of the thinner ones and keep going up until the noise goes away. This is a common problem so don't feel like you car is the only one doing this.

Twisted_Metal
10-10-2007, 12:51:22 PM
Use a 1/8" drill bit to check the starter/flywheel clearance. :D

Put a 1/8" drill bit between the flywheel teeth and the starter shaft. If it's too tight, add shims till it clears. If it's too loose, remove shims.

75LTCAMARO350
10-10-2007, 03:50:18 PM
How do I check the clearance? The area is all blocked correct? It is an automatic.

Twisted_Metal
10-10-2007, 04:21:15 PM
Take the torque converter/flexplate cover off. (Four screws.)

You will be able to see the gap between the starter shaft and the flywheel.

75LTCAMARO350
10-11-2007, 08:48:04 AM
I checked the battery last night---It is a rather small Die Hard Weatherhandler with only 525 CCA. Is this enough power to crank the car correctly???

Thx so much!!

Twisted_Metal
10-11-2007, 09:37:00 AM
525 CCA is fine unless you've got a very high compression engine.
If it's holding a charge and turning the engine over.... It's good.

75LTCAMARO350
10-13-2007, 09:06:44 AM
OK The clearance between the Flywheel and the starter's teeth is approx. 1/2 inch!!!

How do I correct this?? The gap should be about 1/8 inch correct??
Will shims correct this big of a gap??

All I see are 2 bolts holding the starter on. (there are no washers or any thing on these bolts). Are there more bolts?

Side note: Not urgent-- an exhault warm up baffle pipe that feeds warm air into the air cleaner housing neck is now partly broken off and is laying on the starters wires---how do I remove or fix this?

Thanks!!

Twisted_Metal
10-13-2007, 11:41:54 AM
The gap between the teeth is 1/2" when the starter gear is out to the flywheel? I'm not talking side-to-side gap...

If you have an auto parts store near you.... Have them pull a starter off the shelf so you can see the directions for the proper gap. (There will be a sheet of paper with the instructions in the box. )

75LTCAMARO350
10-15-2007, 11:13:56 AM
Ok---How do you check the gap when they are engaged? They engage only when your starting the car correct??

or do you put a straight wire gauge (or 1/8 drill bit) across the side to side gap (non engaged)to get an approx. measure of the engaged gap??

I did loosen up the 2 starter bolts(broke a socket trying) moved the starter around than retighted. Still the same grinding @ starting.

Next step is shimming correct?

angel71rs
10-15-2007, 08:47:25 PM
In order to use the engaged method, you have to remove the starter solenoid, then pull on the iron core it covers so that the bendix moves out to engage the flywheel. Then you use a paper clip between the bendix teeth and the flywheel teeth. Too much of a hassle for me. So I use the 1/8 drill bit method. You put the 1/8 bit across the starter shaft (non engaged), should get 1/8 between the shaft and the tips of the flywheel teeth. There used to be an excellent website that showed this with drawings/pics, but I just tried to access it and got the dreaded 404. I was too lazy do a fancy AutoCAD drawing, so here is a Paint creation, no laughing!

http://i67.photobucket.com/albums/h281/angel71rs/general/shim.jpg

Couple of thoughts: I've seen starter bolts cause grinding. If you examine the bolts, you will see that a knurled portion of the bolt shank actually extends thru the starter nose casting. The holes in the block are not threaded for about the first 1/4". The knurled shanks of the starter bolts register into this 1/4" unthreaded portion serving kind of like dowel pins to positively locate the starter and prevent it from sliding around. Improper bolts will obviously defeat this dowel funtion.

Correct starter bolts with bent tips can also cause grinding; the bent tip moves the starter out of position. Tips can get bent on a bad kcik back. Check the bolts by rolling the shanks on a straight surface and make sure the tips don't wobble.

If you need bolts, they are carried in parts stores in the Help! section. There are 2 lenghts of bolts used in SBCs, corresponding to 2 types of starters. One type uses an offset bolt pattern. These will have one long bolt, one short bolt. The other type uses a straight bolt pattern, using 2 long bolts.

Why 2 starter types? Cause there are 2 sizes of flywheels. Small with 153 teeth, large with 168 teeth. Small takes straight starter, large takes offset starter. I suppose someone could have mixed starters/flywheel size, but I'm not sure that can even happen without being immediately obvious.

As far as shimming, you either have to install a whole shim under both holes, or a half shim under just one hole to get it to where the pin just slides in. It's been a long time since I've done it, so don't remember which action increses/reduced clearance. But when you get a starter from Autozone, it comes with instructions that tell you what effect shimming where has. They use the 1/8 method too, even comes with the 1/8 rod.

CorkyE
10-15-2007, 09:36:44 PM
Ok - got off my FLA and scanned in the instruction that came with my mini starter, should be the same. Note that you can use a small screw driver or such tool and work the starter gear out to the ring gear.

5308

75LTCAMARO350
10-16-2007, 10:47:50 AM
Thx! Corky---The scan doc. is GREAT!!!
If the shimming don't fix it---I will check the bolts.....wish me luck!!!

75LTCAMARO350
10-18-2007, 05:30:28 PM
When I go to shim the starter---Do the shims go on right under the bolt heads or between the starter body where it attaches to the block????

I don't want to screw this up ....if possible.....

Thx!!!

Twisted_Metal
10-18-2007, 05:56:58 PM
Shims go between the starter body and block.
(They wouldn't change the position of the starter if they were between the bolt head and starter body.) ;)

THE KING
10-22-2007, 06:42:08 PM
But, while your looking at the starter, take the time and look at the teeth on the flywheel. Turn the flywheel 360 degrees and look at ALL the teeth. You could have chipped, cracked or broken teeth causing the grinding also. I'm no expert by any means but I did have a problem with my starter engaging properly a while back. Not every starter is made the same. I had two problems. I changed my starter four times before I got a starter that would actually work in my Z. This was after starting with no shims to all the shims that came with each starter. Nothing worked. It was the machining on the starter where it met the surface of the block. After I installed the fourth starter it worked great and I didn't have to put in any shims !! When my buddy told me I might go through multiple starters until I found one that worked I thought he was nuts. Guess I was wrong !!

After installing the fourth starter, my buddy came over and we took a close look at the flywheel. It had minor chipping on the teeth where they meet the starter. When we got the fly wheel out, it was cracked almost all the way around the center. Don't know what caused that but I would guess all the grinding and hard engagement of the starter didn't help. Just a thought, you might as well do a quick inspection on the flywheel while your down there.

68400BIRD
10-22-2007, 07:45:50 PM
Another thing to check is to make sure that the flywheel (flexplate) and the starter are for the right tooth combo.

75LTCAMARO350
10-25-2007, 09:46:56 AM
Ok shimed it. Got it sounding a little better. Still has some vibration and sounds like a model T cranking, but it does start!

The flex plate is worn...has some teeth chipped and some teeth worn out more than others. Do you think I can just leave it like this? Than when It gets worse just change the flex plate and get a new starter??

How much does it cost to change the flex plate??

Thx!!! everyone!!!

THE KING
10-25-2007, 07:59:24 PM
It depends on how bad you want to let it get. If it was me, I would buy a new flex plate. OEM will be roughly $35. If you decide to upgrade and say go with a TCI flex plate, it will be roughly $70. I personally upgraded to the better flex plate. The starters are not that expensive. I would buy a new one. If the new one doesn't work, take it back to the parts store and make them exchange for another new one. I would do this until you find the right starter that works and sounds correct. Once again, you may have to shim each one until you get the correct starter.

There's nothing like waiting until it gets worse and your on the road broke down somewhere with no way to get home. What will you pay to have it towed? May be worth just getting it fixed now. But that's up to you. Changing the flex plate isn't that tough to do if you have the right tools.

Changed mine during a Bears game last year. But I also have a lift in my garage which made it easy to do. Well, the transmission jack also helped.

Anyway, good luck with whatever you decide.

CorkyE
10-25-2007, 09:38:33 PM
Agree - change the flex plate before it leaves you in a pickle. If the starter gear teeth don't show any signs of unusual wear, you might be alright there.