350 Cracked Block

GMC350TRK · #1 02-07-2005, 04:07 PM

Have 1986 GMC 4x4 with 350 motor. Block is cracked where the starter attaches. The bolt hole is broken out. Starter will not stay tightened. Is there any way to fix this problem short of replacing the block? Seems to be a common problem with GM. Wondered if anybody else has a similar problem.
Thanks

mike123 · #2 02-07-2005, 04:11 PM

can ya drill it tap it out and put a helicoil in?

GMC350TRK · #3 02-07-2005, 05:22 PM

Mike,
Thanks. I think this had already been done once on this motor. Just bought the truck a few months back. Haven't driven it very much but just enough for things to loosen back up. All seemed well during the test drive and purchasing phase, of course. Only a couple of weeks ago did it develop a noise that we traced to the starter. One hole was broken out and the other apparently is stripped. No way to tighten down the bolt. I'm hoping to avoid having to buy a new block if there are any other alternatives. Thanks

mike123 · #4 02-11-2005, 03:44 PM

well if your in the CA , LA area i just happen to have a 350 short block that is all tore down that i dont really need , sense i have no money to complete the build
its from a 96-99 i bought it mainly for teh heads but i did plan on rebuilding it

GMC350TRK · #5 02-11-2005, 04:27 PM

Mike,
Thanks for the offer but I'm on the other side of the U.S. from you. Guess I had better be looking around for one, huh? I had hoped this problem had been frequent enough that maybe there was a fix for it besides having to replace the block. Just a quick fix that lasts long enough for some "unsuspecting" buyer like me to not pick it up in time. We live and learn. Thanks again for your responses. This is my first attempt at seeking help through this site. I'm sure there will be other challenges ahead as we try to keep this truck on the road. It actually belongs to my 16 year old son. He saved up his money to buy his "dream truck" and now after 5 months it's dead in the water. Not a good way to start out with his first vehicle. I should have taken it to a shop somewhere and had it inspected. Maybe we could have picked up on the problem beforehand.

Oddly enough, my first vehicle was a 1955 Chevy 2-dr HT with the exact same problem. The block had cracked right through the bolt hole that held the starter on. I remember going down the road and the starter literally falling off the car being held only by the wires! Talk about a lot of noise and thumping! I learned to keep extra starter bolts in the car just for such emergencies. Oh, those were the days.(early 70's). Thanks again.
Danny

mike123 · #6 02-11-2005, 11:16 PM

well , if your just tryin to do it for a little while , maybe try jb weld? or that 2 part appoxie stuff , that stuff is like a rock

blabhern · #7 02-13-2005, 09:09 PM

is there enough metal there to possibly go to a nut and bolt with maybe a washer or something similar? I can't picture the area you're talking about but it may be a temp fix for you, maybe long-term.

BlueMonster · #8 02-14-2005, 11:21 AM

What if you were to weld the area to fill it up. Keep welding until you fill the area completely, and then take a grinder to it to grind it back to shape. Then drill a new hole for the starter. Would that not work?

GMC350TRK · #9 02-14-2005, 02:50 PM

Now that's an idea. Will look at the area and see if this could work. Thanks for the ideas.
Best Regards,
Danny

Gooseneck · #10 02-16-2005, 11:28 AM

I really dislike people who rip-off 16 year olds on there first vehicle. I think you should let a certified welder or at least a good welder take a look at your block. Maybe studs could be welded into the block to mount the starter or the starter could be spot-welded to the block. This would keep you cranking at least for the life of the starter which could be the life of the truck. The only thing is because of the material of the block and starter this would need to be done by a certified welder or at least a welder that is familiar with welding such material. I have known of welders that could fix anything from a broken heart too shattered dreams. In any case it could get you by, much cheaper than a block replacement (or actually engine replacement) and hopefully get your son back on the road again.

GMC350TRK · #11 02-16-2005, 12:30 PM

Thanks, Gooseneck. I have been told my my mechanic that to do a proper job with welding and getting the bolt holes to line up perfectly again, I will probably have to take the engine out of the truck. There isn't a lot of room underneath to do the quality job that will be needed for it to last. If we're looking at having to take out the engine, then I think I would rather go ahead and go with a replacement block while we are at it. What do you think? If something were to go wrong with the welding job or the starter, then I'm right back to this point again.
Thanks,
Danny

BlueMonster · #12 02-16-2005, 12:41 PM

I guess that would depend on the budget too. If you wanted to make lemonade out of lemons, you could spring for a performance short block or even a whole new engine with ported and polished heads etc.

If money is tight, maybe the better idea would be just to take the engine out and have the block welded. If the welder does a good enough job, you may not have a problem replacing the starter should anything go wrong with it. Whereas on the other hand, if you do an engine swap for another used engine, you might be exchanging one headache for a host of others.

84fiero123 · #13 02-16-2005, 03:22 PM

i agree with gooseneck get it wwelded by a pro, any journeymen welder or fab shop in your area with a certified welder on staff should be able to fix that with little trouble, dont weld the starter to the block tho tig it solid and drill it out and retap, it should be able to be done in the truck. you may have to drop the exhast pipes to getwhere you need to be.

GMC350TRK · #14 02-16-2005, 03:36 PM

Thanks for the encouragement. I will find a welding shop and discuss this with them. Sure sounds a lot easier than taking out the engine.

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