i just built the motor in my sig and i just baught the second starter for it beacuse the housing keeps cracking. they both sound fine when i started the car no grinding or anything unusual sounded like it should and about 2 weeks later they just crack the only thing i could think of was that the starter gear is to close to the flexplate but wouldent that make a grinding noise. any ideas

 

Are you running the brace on the back end of the starter? Without that brace there is more stress on the nosecone that, on harder to start engines, will eventually cause it to fail.

I assume this is a regular staggered bolt GM starter.

 

I just had this problem a few weeks ago. The nose cone on my starter busted in half. I did notice a brace of some sort behind the starter and it wasnt connected to anything, and that got me to wondering. I put on a new starter but didnt connect that brace, so perhaps I will get that taken care of.

 

I had that same problem. I wasn't running the brace on back. After ruining my cores I bought a mini-starter. So far I've had no problems. Mini-starters' don't require the brace due to the motor being offset from the bendix and starter drive.

 

The improperly installed brace it what is causing you problems.

Here are some thoughts to make sure you don't have problems again:

Make sure you haven't bent the bolts that were holding the starter. If they are not perfectly straight either get used bolts or replacement bolts that are grade 8 or better. Many of the auto parts store replacement bolts are pretty soft, grade 3 at best.

Make sure the bolts are torqued properly so that the nosecone is held securely but not flexed any more than necessary.

GM produced several nosecones over the years. There is a 4x4 nosecone that has a smaller opening to prevent mud and sticks from getting in to the starter. Typically these starters also have a rubber seal inside to keep the motor dry. The real benefit here is that it makes for a much stronger nosecone. The cost difference is not that big, so you might consider picking one up. The only catch is to not let the parts guy select "unknown" or 2 wheel drive when punching it in to the computer. In those cases they will get the same basic starter you have been getting.

Typically what will bust next will be the cheap bendix they use in these starters. I haven't found a bendix yet that will last for more than a year or two, but at least these steps have kept the other parts of the starter alive. For most applications the average bendix will probably last for many years.

 

This can be a most vexing problem because the engine starts and runs just fine.
Here are some tips:
1. it has nothing to do with whether there is a back brace on the starter or not. It's purpose is to keep the starter from loosening the bolts or fatigueing them in two by preventing the starter from rocking.
2. it is not an alignment problem. All alignment problems will result in noise and excessive wear on the bendix gear.
3. it is almost always an ignition problem, usually a defect in the distributor or ignition primary circuit that causes an early spark to occur after the first cylinders have fired and the rpm is increasing.

You can troubleshoot this by making a delay with an oil pressure switch so the ignition is off until the cranking speed has stabilized.

Possible causes in the distributor include a loose/misaligned reluctor wheel in CC distributor. Slack in the spring and weight system on non-cc distributor.
A problem with the gear on the distributor: loose roll pin or gear problem causing the shaft to "chatter" at a specific rpm on both systems.

Possible primary circuit problems: a relay (like fan or FP) switching on and off an inductive load as the engine starts cranking inducing a reverse voltage spike causing the coil to errantly fire.

Possible (unlikely) mechanical problems that can cause an impact load on the bendix: loose flexplate bolts, cracked flexplate, broken crank. These may not make any noise at all.

Putting on a mini-starter will remedy the problem short term since they have no nose-cone to break, but if they are being impact loaded the bendix clutch will fail instead.

If you find the problem be sure to post back the cause, for future searchers.

 

I broke a starter nosecone in an interesting way some years ago. I was working on the throttle body, and a ton of gas got down into the cylinders. Went to crank it up and BAM! Nothing like hydrostatic lockup to bust a starter. I'm actually glad that's the only thing that broke though. I've heard of connecting rods getting bent that way too.

 

could it be that the distributor is to far advanced its a brand new distuibutor beacause the pick up in the old one went bad so i just got a new eccel one and havent checked the timing yet. i just got another starter and before i put it on is there any way to check and see if the starter drive gear lines up with the flexplate without the starter turning the motor. thanks

 

Yeah, your timing could possibly cause them to crack if it's too far advanced. You'd be able to tell by the sound when you're cranking it over though. When you have too much advance, the motor will crank real jerky and slow until it starts. If it's cranking over at a normal rate, then that's probably not it. Not really sure how you'd go about checking the alignment between the starter gear and the ring gear on the flexplate. Did they give you any shims with the new starter? They usually give you a small metal rod along with the shims that you use to check the distance between the ring gear teeth and the shaft that the starter gear comes out on. You can try checking that clearance, and maybe put a shim or two between the starter motor and the block to see if it makes any difference. Next time you get the motor running, you ought to get your timing set right so you can eliminate that as a possible cause too.

 

i think it is beacuse it will turn over like one time then make a horrible noise and wont turn over any more and i didnt have any shims in the last one and it worked fine until i put the new distributor in and i think i had it set to far advanced and it cracked it. hopefully thats what it is.