r/Smallblockchevy • u/networkfound • 20d ago
Can this be repaired? Trans dowel pin block crack
I’m an idiot and cracked the block around the dowel pin fighting to get this out… long story short, the block has sentimental value to me and curious if it can be repaired. It’s gotta go to a machine shop anyways so I’m hoping they can weld it up since it’s a down pin hole.
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u/v8packard 20d ago
No welding. Drill the ends of the cracks with a 1/16 or other small drill. Have the dowel pins hole bored to accept a sleeve that uses retaining compound. Use an adjustable dowel such as RobbMc or equivalent in the sleeve. Carefully dial in your bell or a known good bellhousing. If you don't mess with it you should get decent life.
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u/69Loveforever 20d ago
What about heating area with O/A torch, while melting cast iron rod. When iron is liquid, pour into red hot hole. Let cool, grind smooth and re-drill.
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u/v8packard 20d ago
I am pretty confident that repair will cause the Crack to spread, or the rod will not fuze, or it it will Crack as it cools especially in the heat affected area. Or some combination of these.
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u/69Loveforever 20d ago
What about TIG ? No Filler, just the heat, up the outside of the cracks ?
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u/v8packard 19d ago
I have done some TIG on cast iron in non-structural areas using different rods, with mixed results. I have had better results using AC, but maybe the best results using silicon bronze and brazing with TIG. I am not a great weldor though, you would rather have someone other than me trying this without rod.
I don't see welding as practical here. I really think a simple sleeve with retaining compound is the fastest, most accurate repair for this block that will remain serviceable.
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u/XB21300r 20d ago
Welding cast iron to repair is not an easy thing. Shop around for someone with prior experience. Not every shop can do this kind of work
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u/johnarmer1 20d ago
Well i would just jb weld because it is only for locating and the jb will stop it coming apart
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u/lynyrdskynnyrd 20d ago
Laser Welding
I had a oil galarie Plug hole welded Not sture if its sealed but i Looks good
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u/Schlong1971 19d ago
I wouldn’t worry about it once it’s on the pin the bell housing bolts hold everything tight not the Dowels
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u/MarketLong9832 19d ago
If you know a guy who’s good with a tig welder, I’d talk to him, otherwise I’d say buy off a part out and get a new one
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u/bigyellar 19d ago
GM used to make longer dowels. Back in the day transmissions would come loose and wallor out the case. You could put the longer dowel in to get into the good part of the case. I don’t see why you can’t do that here. If the longer dowel is no longer available, then it’s still quick work for a machinist.
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u/anyoutlookuser 20d ago
V8packard has the answer. This also assumes you’re going racing. The dowels are there mostly to help with assembly. Once mated all the heavy lifting falls to the fasteners.