The last piece of the puzzle to recovering from the broken crank club is my transmission brake drum. My machine shop flunked the one I had been using because he did not like the shaft wear, and each hole for the bolts holding the driving plate each had a very noticeable crack (big) on the inside of the column in the drum.
I have found a very nice looking drum, everything looks good, shaft like like new, except 3 of the holes have a very, very small almost un-noticeable crack in them, 3 do not. Is this drum still usable? My T cash budget is at a very low point right now, with the expense of the fresh engine. I would suspect there are a lot of drums in use with these cracks that have gone in-noticed . My machine shop ask me to put this out for opinions.
Personally I wouldn't risk it since it is apart. J&M makes excellent drums and a good drum equals peace of mind. But if you really want opinions, pictures of the cracks would be helpful.
You are leaving something out, year! Guessing you are talking about 1926/27 big brake drum.
Here is my OP, others will differ. If you are talking about 26/27, the drive plate is down inside the brake drum. Chances are a lot of the brake drums will have cracks at that location because of how thin the casting is and probable have been that way for lots of years. I would use it.
I take 3/8 fine threaded bolt/nuts to 35 but here is one place maybe a bit less might be prudent, tight with a 6 inch 9/16 wrench.
After the people have said their piece it will be up you to make that decisions.
Yes it is a big drum 26/27
I'm with Mark here. I don't think it will be an issue. I suspect there are hundreds out there right now with the same cracks and I have never heard of one actually failing due to this. However, a crack that runs outward, into the outer diameter of the drum is a dud.
Man, I don't know except for the fact that it would bother the heck out of me if I re-installed it. I'm a worrier! Your choice of course ( price of a new one ect.) but you're apart and that's one heck of a consideration as to replacement. Just think about doing it again later. I'd definitely feel better with new.
I have taken apart scores of T transmission and lots of them are cracked there. Never have I seen one fail. Don't worry about them. Use it.
I bought a 21 T engine 5 years ago at Chickasha and after getting it home and dissembling it I found the low speed drum had a hairline crack across the face of the drum. The bands weren't chewed up in it. This was an engine that was greasy and taken from a running car a few years earlier. No telling how long the drum was cracked while it was in use. I have a feeling a lot of T's ran cracked drums for years until they failed or if they ever did.
But I did rebuild the transmission with the best drums I had that weren't cracked. To each his own I guess!
I agree I search out a new drum old but the new ones are worth the money