: Starter Grinding



csbuckn
06-13-13, 10:44 PM
Check out the video. I've had this problem ever since I changed the flexplate last year. Before changing the flexplate, it sounded funny but started good each time. After changing, it does all kind of stuff. I took a video last year and posted on another forum but didnt get any results. I've changed the starter twice and both times, the starter nose cracked on the first start. I can put my old starter on(the one on the car now and in the video) and it will crank funny but it wont break. I've shimmed this starter in and out to every possible position but nothing changes. Its driving me crazy and its been going on for so long, I dont even get embarrassed anymore. HELP

http://www.youtube.com/watch?v=fCUglkXAoec

tsgrpr97
06-14-13, 01:31 AM
How are you shimming? You should disconnect the motor from the solenoid, so it throws the pinion out but doesn't crank. When the gears are meshed there should be just enough clearance between the teeth to fit a straightened paper clip. Even a tiny little bit more or less and you'll be breaking the nose on the starter or busting teeth off of the flexplate.

The Ape Man
06-14-13, 08:10 AM
Cadillac powered Cadillac starters do not use shims. The engines are built to tighter tolerances than other brands.

The rear starter bracket must be in place and connected properly or starters will continue to break.

There's more info on the bracket on this site.

tsgrpr97
06-14-13, 10:01 AM
Cadillac powered Cadillac starters do not use shims.

I wasn't aware of that. Learn something new every day I guess :)

csbuckn
06-14-13, 10:28 AM
I was shimming correctly but didnt have the rear bracket for a long time. I recently got the bracket and it didnt make a difference.

deVille33
06-14-13, 11:43 AM
Make a close inspection of your starter nose housing. Pull the nose off and check the bushing, I have seen these starters wear through the bushing and the starter shaft still spin on the aluminum housing material. Look at the teeth on the front of the flywheel. Rounded or edged, your pinion isn't setting deep enough. Is the pinion hitting the face of the flywheel? There should be a thrust washer on your starter shaft. If missing your pinion may be traveling too far. From your video, this appears to be the case. Any minor cracks in the starter nose are suspect. These Cadillac noses are lacking in support material and the high torque of the starter will test the nose housing. Yes, and that little strap on the back of the motor, that Ape Man mentioned, is a very important piece often thrown out for the extra twenty minutes it may take to re-install it. It helps to limit the flexing of the unit. :duck:

The Ape Man
06-14-13, 06:57 PM
One start without the bracket is enough to crack the nose.

Also make sure distributor mechanical advance isn't binding. Advanced timing when trying to start a hot engine is murder.

MrHolland
06-14-13, 10:47 PM
I had this same problem on a BBC. Turned out the block was cracked where the starter mounted. Destroyed a few starters before figuring out my problem.

lacville78
06-15-13, 04:40 AM
Advanced timing when trying to start a hot engine is murder.

Very True! I wish I wouldn't have learned that lesson the hard way. I broke the block by the starter on my camaro from too advanced timing.

Cadillacboy
06-15-13, 03:40 PM
For the life of me I would have never imagined that a starter might be culprit to a engine block breaking ,something new on my side as well

Fleetwood472
06-15-13, 08:17 PM
Not true. They do use shims. They use 1 shim. If you look in a 77 Cadillac manual it calls for 1 shim.



Cadillac powered Cadillac starters do not use shims. The engines are built to tighter tolerances than other brands.

The rear starter bracket must be in place and connected properly or starters will continue to break.

There's more info on the bracket on this site.

csbuckn
06-15-13, 09:32 PM
I'll have to check the block for cracks. After all the shimming I've done, it does the best without any shims. Did y'all notice in the video at :55, the starter actually stopped mid spin and stayed engaged to the flexplate. It does it again at about 1:15.

tsgrpr97
06-15-13, 09:40 PM
Not true. They do use shims. They use 1 shim. If you look in a 77 Cadillac manual it calls for 1 shim.

See I was assuming it would. I wouldn't expect any on a modern powerplant but from the 70s yeah. I've never had reason to check my coupe but my buick 455 had a rear bracket and it needed to be shimmed. Would the starters be shared across brands or would the 472/500 have its own?

The Ape Man
06-16-13, 10:50 AM
Not true. They do use shims. They use 1 shim. If you look in a 77 Cadillac manual it calls for 1 shim.

Who published that manual?

deVille33
06-16-13, 10:59 AM
GM used two basic motors, but there were some variations set in the internal winding configurations. The 1969 Pontiac SM and the Chebby manuals have illustrations of the various windings and descriptions of their applications. Cadillac did not have this because they only used the high torque starter for their single engine application. The Cadillac starter nose housing was shared with the Chebby big block engines, which also used the high torque starter. Pontiac, and if I recall correctly, Buick, mount on the opposite side of the engine block. These starters, especially the Pontiac, have to be shimmed. The depth of the pinion gear tooth into the flexplate ring gear has to be checked for proper alignment. To do this, I pull off the nose and remove the plunger lever so the pinion moves freely on the starter motor shaft, then replace the nose housing. Remount the starter and check the pinion to ring gear depth. A paper clip wire is the proper thickness to use as a gauge, about .018 inch. The wire should fit into the space at the bottom of the ring gear tooth and the top face of the pinion gear. When you do this, check the plunger lever bosses for wear. If the bosses are flattened out, the throw will be lacking. Also check the return spring tension. If the spring has been overheated or fatigued, the pinion will hang on a driven ring gear and not return as it should. This may seem like a lot to do for a starter, but for proper operation and for long term operation it is required. :)