Posted By: 4spdana
crack in block between dowel pin&trans bolt - 03/22/15 07:55 PM
dowel pin for trans on this 76 360 was missing and noticed a crack, not quite all the way through the starter side of block.
could V it out, weld and surface back of block.
its a stock re-build job for a friend, will most likely need boring.......maybe its cheaper to get another block.
Thoughts??
Posted By: 65dodgebob
Re: crack in block between dowel pin&trans bolt - 03/22/15 08:15 PM
getting another block is a good idea, but considering where the crack is I would try to fix it. start by drilling a small hole (1/8 or 3/16) at each end of crack so it will stop spreading. grind out and fill with nickel rod or you could possibly braze it with a torch. just grind weld down flush with the block surface (check with a straight edge). just make sure weld is not sticking up. should be fine.
Posted By: 6PakBee
Re: crack in block between dowel pin&trans bolt - 03/23/15 01:41 AM
If it needs no machine work, it's worth a try fixing it. If it needs boring, I'd look for another block. Just my
Posted By: Stanton
Re: crack in block between dowel pin&trans bolt - 03/23/15 02:36 AM
The dowel just positions the trans, the bolts hold it secure. I'd put the dowel in and leave the thing alone. It likely cracked because some moron used a 1/2" dowel in a .496 hole. Use the correct size dowel and it will be just fine. Once the trans is bolted up there is no strain on the dowels.
Posted By: dogdays
Re: crack in block between dowel pin&trans bolt - 03/23/15 05:03 PM
Mark this day on your calendars, guys! Today I actually agree with Stanton.
The dowels are there to get the transmission centered on assembly.
Use it, no fixing required. Be sure to torque the bellhousing bolts to spec.
R.
Posted By: John_Kunkel
Re: crack in block between dowel pin&trans bolt - 03/23/15 07:45 PM
Since the crack extends into the threads it's possible that the threaded hole will open up a little when the bolt is torqued, I'd install a Heli-coil in the threaded hole and run it.
Posted By: John_Kunkel
Re: crack in block between dowel pin&trans bolt - 03/23/15 08:09 PM
The dowel is a critical part not only for alignment but also for torque restraint...ever see those GM one-size-fits-all thin plate adapters to swap transmissions...the dowels and two bolts are that are used for torque restraint?