sbc starter bolt problems?

I've been having a problem with my starter gear grinding on the flywheel. It seeems like its the bolts. It loosens up and then grinds because its not positioned right. I noticed one was stripped out, so I replaced it that seemed to fix it for a while but then the other fell out...it was stripped too. These were cheap looking bolts. I've switched starters/bolts and same thing happened after a while. The wierd part is I had this starter on the car for a long time with no problems until this started happening. Seems like when I pull the starter off, then put it on and tighten the bolts its ok for a while then it happens all over again. The bolt holes in the block seem fine, I can thread a bolt in no problem. I thought maybe the one hole was stripped or the block was cracked, but its not. If I grab the flywheel, I can't feel any play in it and the engine runs strong. I've tried loc tight too.

I ordered a set of ARP bolts to see if that helps..but I have a feeling it might not. The strongest bolts I've found in the length I need was grade 5, I think thats part of the problem. I can't get them too tight with out the strippping. I'm running a mini starter now, I might switch back to a stock one, but its a pain because I will have to remover my headers to get the big stock unit in. Would the timing do this...I'm going to check it tonight, maybe it slipped or something.

I had to tow the car home last night, then I thought I fixed it, drove to work and now same thing happened...looks like I'm getting it towed again tonight.

Anyone had a similar problem? Could the engine be worn to the point where the flywheel moves and doesn't line up with the starter gear right sometimes? I figure the engine would feel worn out if it had a problem like that.

Thanks

 

oh yeah, had that problem before.
Look here:

http://www.jalopyjournal.com/forum/showthread.php?t=36604&&showall=1

 

Thanks, comforting to know I'm not the only one thats had this problem. I'm thinking its either just ****py bolts or else maybe the bolt holes in the block had inserts in them that have gotten messed up. When I took out the stripped bolt I noticed it had metal wound into the threads. I thought it was from the bolt, because I could see the threads flattened out on the bolt, but maybe some of that was from the hole.

I'm going to throw a new mini starter I have on the shelf with the ARP bolts in it, when I get them. If this doesn't work I'm going to see about putting new inserts in the holes in the block.

I'm not sure how to tell if the block has been helacoiled already. When I'm under the car I can't see too much, but a bolt threads in ok by hand.

 

The grade 5 bolts brobably didn't have the knurled part to help them stay tight. I think the ARP's will take care of your problem; if not, helicoil the block!

 

try a bolt a bit longer but not so long it bottoms out so you can get a bite on some fresh threads up there and a lock washer?

 

Ya, I'll try that too. I was thinking the same thing...unfortunately the ARP bolts are pretty short according to the catalog. 3.7" when the ones that stripped were 4". I have some quality stock bolts that are too long, maybe I can use some spacers to get them to work, if the ARP's are too short.

 

It sounds to me like it has been helicoiled.
Heilcoils will flatten out the threads on the bolt.

A threaded insert is the best option in my experience.
It works just lika a heilcoil but much stronger.

If the block has been taped for the heilcoil you can run the same size tape up the bolt hole and clean out the threads. Thread the insert in and tap in the key tabs and your problem will go away.

I think it would be a 5/16 O.D. insert with the 3/8 I.D. for a 3/8 starter bolt?
something like that.

look here:
http://www.carrlane.com/Catalog/ind...006280B1713050245221E0107070F1A3C3B2853564755

 

OK, I took the starter off again and wiped the mounting surfaces clean. It looks like there are 3 small stress cracks around the out side bolt hole on the block. I can't tell if this is the problem but I have a feeling that it is. Bolts still thread in and seem stable but I think maybe under the torque of the starter that it moves a little.

I talked to a shop I trust on the phone, and he said he can get a stud welded in, and that it was really the only good way to fix it.

I guess I'm going to let them look at it and if they want to weld a stud in I'll let them. Seems like a sloppy fix but if it works at least I'll be able to drive the car without problems....meanwhile I'm thinking I'll build a new engine, maybe its a good excuse to upgrade to something either more powerful or at least cooler.

 

I just got over that prob using a mini starter. The ARP bolts i ordered were either too long or too short so i used the steel ones that are knurled and the prob is solved for the time being. Good luck!

 

I have a mini starter on it now. I ordered the ARP bolts and they were too short...3.75" compared to the 4" ones I was already using. I'm thinking of trying to switch back to a stock starter with the stock bolts for it to see if that helps, but I might just need to get that stud welded in. Its a pain to get a stock starter mounted in this car because of the headers I have on it.

Thanks for your help.

 

I can't recall how things look back there but recall my dad drilled thru them threads out the top and puts nuts on 1 or 2 of them, I was an arrogant little kid at the time so didn't pay a whole lot of attention to even the kind of rig he was repairing but do recall him doing it

 

Just take a stock starter bolt that's too long and shrten it up a 1/4" so the knurled part is still in the mini starter hole then run a tap down so you have enough threads to seat in the block. Worked on my mini starter.

 

I just remembered.........On my other motor that has a mini starter, I used the stock knurled bolts that were too long and put them through SBC intake valve retainers to take up the slack.

Ghetto...... but functional!

 

You need to use starter bolts with the knurled area. A stud id a good fix in theory but can you get a starter over a welded in stud? It would take a lot of room. Chevy put those tail braces on starters for a reason. Some cars get by without one and some don't. Get one.

 

The Chebby starter is supposed to have a little support strap on the front of the starter. Most of the time that gets left off when the starter gets changed. On about 90% of 'em it doesn't make any difference but once in awhile you run onto one that needs it. Who knows why. if the ARP bolts don't cure it you may have to support the front of tha starter.
You also probably need genuine starter bolts (the ARPs should cure that) they are knurled where that p*** through the starter.

 

Problem fixed. The problem ended up being a really stupid one, and an easily fixable one.

Once I got the car on a lift we could see that the starter bolt was bottoming out just before it clamped down tight on the starter. It felt like the bolts were tight as well as the starter, but the starter must have been just loose enough to allow the starter to shift a bit and get out of alignment under the torque of the starter. A few washers on the bolts and it seems to have fixed the problem. I guess the cracks I thought I saw are just casting marks or something.

I probably could have seen this by laying under the car in my driveway, but usually when I was working on it, it was in the afternoon almost dark or in a parking lot, with the tires still on the ground. Not to mention I loaned my big jack to a friend and he broke it.

Anyways...thanks again for all your help.

 

Well after all that time trying to figure this one out. I think I finally got it fixed, about 2 weeks of no problems, then today I was going to leave work for lunch, and it started grinding again. I reached under car, bolts still felt tight. Then I looked under, and the whole nose cone was broken off.

 

Just no luck at all, huh?


jerry

 

Was the broken starter nose on the mini or original starter? I've never had a mini starter, but on stock Chevy (1970 or older) starters I always replaced the bolts every time I pulled the starter off. Also I always used genuine Chevrolet starter bolts from the local Chevy dealer. However I was lucky, cause the parts guy was an older fella and had been there since the early sixties and could read a parts book, so he knew what to order. One thing this guy said, was to replace the bolts each time I pulled the starter off, and use genuine Chevy starter bolts. The knurling on the bolts wears off after it's used a couple of times, and then won't stay tight.

 

It was the mini type, the one that they use on some of the newer gm engines. I've had the stock type crack before too, but this is the first time I've had so much problems. I'm going to put a new starter on tomorrow, the bolts I have are new, but I wish I could find a good stock bolt that was the right length. The arp bolts I bought ended up being a little too short.

Thanks for the advice, I might have to call the GM dealer and see if they got the correct bolts.

 

Sounds like the exact problems i had with my new mini starter on my block. The ARP bolts are either too short or too long. After taking my stock bolts that were 1/4" too long i cut them off and run the tap down them just to the knurled part of the bolt. It tightened up and so far it is still working good.

 

It's my opinion it is the bolts but also measure the inside diameter of the top hole of the starter motor.
All starter motors made today are universal so they can be used with either SAE or metric bolts.
Use a veneer caliber and start checking the diameter of the bolts and the inside diameter of the top hole and then try and find a bolt that fits into the hole better.
Next install the bolts into the starter motor before you install the starter motor and see if you can fit the end of a paper clip into the ends with the treads. If you can look for different bolts that give you a tighter fit.

Have someone sit in the car and crack the engine over while you lay on the ground and watch the starter motor and in my case with it torqued down to 45 foot pounds with brand new bolts in it I noticed it was moving up and down and that is what is breaking the shaft and it will do it each time until you find a bolt that fit's tighter.

After measuring the shaft diameter of about 20 new bolts you will the problems in the bolts and also in the ****ping sizes of the hole on top of the starter motors.
I have even thought about installing a bronze bushing in the top hole to get a tighter fit between a SAE 3/8 starter bolt.
Once you start looking at the play between the bolts and the size of the hole measured by the both holes you realize why the starter motor is moving around and not staying in place.

A front support bracket is also a good idea but will not help until you the correct bolts holding the starter motor in place first.

Jimbo

 

I'm thinking that in 10 years he may have already solved the problem.