MTFCA Forum

Hey guys

I have now seen that the reverse and brake drums of the gearbox are no longer so good.
They don't have any cracks.
The gears are fine too.
Worst of all is the braking drum; you can see it in the pictures.
Now the question: what to do?
would like to install new ones but they cost so much money at snyders.
turning with a lathe is not allowed, right?
Has a good used one or an address for new ones. Or would you reinstall them like that?
greetz patrick

If you worried about a few casting pits in the surface then you would be scraping just about every drum in T transmissions, that reverse one will be ok, give it a polish in a lathe with emery cloth. As for the brake one, that's well worn but best to leave the edge that high to match the height of the hi/low drum, use as is or they would all need to be turned town and polished to have matching height.

It looks to me like the rums were rusty replacements and the cleanup was rather rough. If they are otherwise sound, I would have them ground rather than turned in a lathe. The finish is much better when the drums are ground.
Frank makes a good point. leave the brake drum and driven plate bolted together so they are both ground to the same diameter.

Allan from down under.

I have used worse drums for many years of touring. I use wood linings and in this case you may have to drive a ways to "break" them in. To me the wood linings don't heat up like kevlar. Just a poorboy speaking. Dick C.

All I can say is be careful. If you are spending the time to pull the engine and do the work have the drums magnafluxed. J&M Machine did mine and found cracks that I never would have been able to see. So could you use your drums? Sure they would work. However, it could be a grande waiting to explode. If it does you could destroy a lot more of the trans and motor. So you just have to ask yourself how much excerptible risk are you wanting to take. Good luck with your project.

This low drum looked OK when the transmission was rebuilt. I'll replace it with one of Dave Nolting's new drums. Yes, it's expensive. But I won't worry about it going to pieces hundreds of miles from home.

Agree with Mopar man. Make sure they aren’t cracked. If there isn’t any cracks your good to go. Clean them up a little better as others have suggested.
Original T transmission drums that look good could have very small cracks in them and run for years with no issue. It could very well be they were that way from the factory.
For the amount of work to rebuild and engine and time involved it’s worth it to have them checked for cracks.
It’s a good idea to not remove to much from the drum to make them super smooth. Remove just enough as necessary.
There have several posts over the years about this before.
Someone should know the max you can remove so you don’t make the drum to thin.
I think the original OD is 7 1/2 inches as I remember.

Don't turn them. Polish with sandpaper. As long as there are no high places or sharp edges, they shouldn't be a problem. Check also the web inside the drum. Sometimes cracks appear there. The most critical drum is the low drum because it is thin and gets more use than the reverse. The brake drum is a bit thicker and will be fine. This, of course, depends on proper adjustment of the bands and cams in pedals must also be good so the band is completely loose when not being used.
Norm

OK
We have a spray at work that checks welds for cracks.
This spray is also used in engine construction.
Surely it is enough to examine the drums with it ?!
Do you have the one side where the drums are cheaper than Snyders?

Would you drum and statically balance the starter wreath?

greetz patrick

Go to Dave’s Restoration and Machine in the resources and suppliers page from the MTFCA home page.
He builds drums and will give you a good deal. He’s a good guy and knowledgeable. His phone number is there.

What grit sandpaper?

In my opinon Dave's Drums are the best way to go.Here is his email davesrestoration.machine@gmail.com.
While you have it down do it right. You won't have to worry about and you won't have to redo it.

Yes!
He will work with you on the drums and if your drum gears are still good he will install yours and save some money.

4banger1988 wrote: ↑

Tue Jan 26, 2021 1:21 pm

OK
We have a spray at work that checks welds for cracks.
This spray is also used in engine construction.
Surely it is enough to examine the drums with it ?!
Do you have the one side where the drums are cheaper than Snyders?

Would you drum and statically balance the starter wreath?

greetz patrick

The Dye isn't as effective as the true magnetic inspection machine. I've shown a typical examples.
We are the manufacturers of the drums and gears that Snyder's sells. Our drums and gears are made to exact Ford blueprint in shape and form.
Yes they are more expensive as it is being sold as a unit not just the drum. it is all brand new. We just sold a complete set of drums to Bavaria.
Yes you would dynamically balance the "Flywheel" Starter wreath.

There are cracks to be avoided and cracks of little consequence. The J & M photos show both. The cracked web in the drum makes that drum a throw away. The small one around the rivet is of little consequence. It goes to the inside of the drum hub, and was most likely created in the riveting process when the gear was installed.
That said, I have removed drums from transmissions that have been in service, and have found web cracks and even drum wear surface cracks successfully bronzed and put back into use. The new drums made available mean we do not have to resort to these means and I am thankful for that.

Allan from down under.

Yes Allan it’s good we have shops making the drums. I would bet these days that there is more attention to detail and quality checks than Ford did. In other words closer attention checking for cracks!

Allan wrote: ↑

Tue Jan 26, 2021 7:45 pm

There are cracks to be avoided and cracks of little consequence. The J & M photos show both. The cracked web in the drum makes that drum a throw away. The small one around the rivet is of little consequence. It goes to the inside of the drum hub, and was most likely created in the riveting process when the gear was installed.
That said, I have removed drums from transmissions that have been in service, and have found web cracks and even drum wear surface cracks successfully bronzed and put back into use. The new drums made available mean we do not have to resort to these means and I am thankful for that.

Allan from down under.

The crack in the rivet hole would lead to the drum failure as every time the pedal is applied the drum is loaded.
In this instance the drum would come loose and end up broken, basically any crack on a load bearing part is not recommended to be reused.
Since we are in business; we can't put bad parts in that would jeopardize the engine or customer.

I understand your position John. Your reputation depends on doing the right thing by your customers, and only sound parts will do in that situation. However, that type of crack at the rivet hole is not uncommon, and if I am correct in my assumption that it has been that way since the rivet was bucked, it is of little consequence. There are others of the same ilk. Cracks from a valve seat into a head bolt hole need no fixing when installing hardened valve seats. Likewise, a crack from a pan rail bolt hole to the outside of the rail. Other cracks are a cause for great concern, especially those emanating from the rear main boss in the block!

Allan from down under.

Interesting conversation about the cracks from the rivets to the gear that you often see on reverse drums..

I had a conversation about 20 years ago with one of our popular vendors whose family has been dealing in T parts for a very long time. His Dad had a friend who worked at a branch plant or somewhere in the Ford supply chain near the end of the T era... And he remembers him remarking that those cracks occurred at the factory!

Just as an aside, Here is a little food for thought for everyone who has a lathe, mill, rotary table, and some time to kill: The disc of ductile iron required to make your own low or reverse drum is $60 from McMaster... Maybe less if you shop around...

OK
Many Thanks
then i will get in touch with dave
and do that again
at least
brake drum and reverse