I bolted the torque tube to transmission this weekend on my 1940 Chevy 1/2 ton pickup with 216. After getting it put together, I noticed a hairline crack at the rear, top of the transmission-see attached pic. I am unsure if this happened upon assembly or if it was there previously. I did not notice it when I had it on the stand. What is the recommended repair method? Brazing or other? Also, is this common? Has anyone seen this before?
Have not seen a crack in that place, but the preferred repair method would be to drill a hole at the end of the crack to stop it from continuing. That spot could probably be brazed, or you could install a series of plugs along the crack. Here's an outfit that does cast iron crack repair and sell DIY kits. Link
That crack isn't in a real high stress area, so once the crack is stop-drilled, you could probably use something like JB-Weld. The issue there would be to get it absolutely spotless so the crack gets sealed. That might be the best approach so you don't have to mess with refinishing the area where the u-joint ball sits.
Kevin 1951 Chevy 3100 work truck Follow this saga in Project Journal Photos 1929 Ford pickup restored from the ground up. | 1929 Ford Special Coupe (First car) Busting rust since the mid-60's If you're smart enough to take it apart, you darn well better be smart enough to put it back together.
There are lots of people getting rid of torque tube drive lines, I’ll bet many have that part lurking somewhere in the dark they would be glad to give you one.
Ed
'37 GMC T-18 w/ DD 4-53T, RTO-610, 6231 aux., '95 GMC running gear, full disc brakes, power steering, 22.5 wheels and tires. '47 GMC 1 ton w/ 302, NP-540, 4wd, full width Blazer front axle. '54 GMC 630 w/ 503 gasser, 5 speed, ex fire truck, shortened WB 4', install 8' bed. '55 GMC 370 w/270, 420 4 speed, grain, dump bed truck from ND. Works OK.
I would die grind, out the crack into a V .Drill hole at end of crack then fill. https://www.muggyweld.com/ this melts at very low heat and is super strong and can be filed smooth. I have used this with great success,on many cracks ,and it has never re cracked . Applies like solder, flows into crack perfectly.