MTFCA Forum

Here is a perhaps simpler presentation of the early Brake Drum to Clutch Drum relationship.


As time goes on, I hope to show more about the later Brake drum to Clutch drum parings.

Jim Key
Accurate Models

Here is an illustration (derived from Ford parts drawings) of why the early clutch drum distance plate was so important. You can see how there is a gap (blue) of @ .057" to .058" between the front face of the lug and the inner drum wall. Enough room to completely jam up a .040" to .042" thick loose ...

As I endeavor to continue my blueprinting project of the Model T Transmission, I have had a lot of input for identifying early, mid, and late version parts. One of the major fact finding missions seems to be coming up with verifiable plan info that shows the parts relationship of the early thrust fa...

At some point along the way of doing these parts schematics (drawings) I want to show the relationship differences between the early drum/shaft/distance plate/clutch drum, vs. the later drum/shaft/washers/clutch drum. This has been a hot topic for many on this forum when trying to rebuild their tran...

I believe from looking at the drawings, the change in the brake shaft dimension is when the top hat bushing (bearing) is removed (revised). However the first time I actually see the new dimensions is on the 1916-1921 T-750 assembly drawing listing the shaft at 4.670" to 4.676". The top revision date...

Thank you, Steve. Much appreciated.

Jim Key
Accurate Models

Hmm, that's interesting, given that the call-outs for the flange have been 1 & 39/64" (1.609375"). I took and subtracted the bushing (1.50?) from the flange and got .109375" as a remainder. Reading other threads, I remembered .110", so your measurement of .111", .111", .112" seem to bear out those p...

Hey, can anyone in the group share the known measurements of the Model T transmission early Brake Drum "Top-Hat" bearing? I see some of them given by Benson Archives parts listing pages, but would prefer to have actual measurements, even if a little worn. Thanks, Jim Key Accurate Models brake drum 5...

I got some interesting information today regarding transmission parts and variations. 3 drawings in particular reveal quite a bit about the transmission Brake Drum and shaft. On the shaft, the earlier version does not have the 30 degree bevel on the flange that connects to the drum. The later does. ...

I'm wondering if someone can give me a few quick measurements on the earlier Drive-plate bolts - 3/8" x 24" x 3/4" or however long they are. Here are the key dims needed.

Thanks in advance,

Jim Key
Accurate Models

I looked at that file years ago, even downloaded it to check it. This is really simplified and has a many inaccuracies in it. So, I put it aside and decided to create my own, that is at least derived from the actual parts. I cannot really comment about the engine and case, as I have not studied it c...

Here are the 4 pages from the Henry Ford Benson archives, listing each Model T transmission part, years in service, and variants. I found this to be of excellent clarity for defining the parts. Thought it might be helpful to share, if they haven't already been posted. Jim Key Accurate Models Benson ...

After further R&D, and re-reading Trent B's post from years ago, I think I am closer to the truth today with these clutch drums.
Benson archives mentions a T-725 (1909) and T-725B (after 1909).

Jim Key
Accurate Models

I just did a look at each parts catalog from 1909 to 1929 and found these years as presentation and order of presentation.

Jim Key

I would appreciate getting some help clarifying these different clutch disk drums.

Thanks,

Jim Key
Accurate Models

Part of what I intended from the start was the possibility of making a "Visible Model T transmission", so that the operation could be understood. Short of that, I may explore Solid works animation of the 3D parts I'm making so that one can observe the action of the low and reverse bands being applie...

I have the general plans from the Henry Ford archives, but did not know there were more detailed plans available from Ford. May I contact you privately to ask who you spoke with at Ford for such info? Not sure I can afford the usage fees right now, but worth checking into. In the meantime, I will ju...

Thank you. This is a project full of ever changing details, as today pointed out.

I admire anyone who has attempted to recreate this transmission.

Jim Key

Okay, getting somewhere. Will add to my notes. Our discussion today has been very enlightening. Here is the back of my brake drum (thus far). I tried to match the photos of the drum we had. Having trouble IDing the Drive plate bolts. Says they are 3/8" x 13/16" - 16 TPI - coarse. Thanks again, Jim K...

Yes, it does. But, I am taking notes and will endeavor to make a plan that reflects what ideal O.E.M.

I suppose then, that shooting for 1920 is perhaps the best shot, or is it 1925?

Is this the correct Clutch disk drum?

Thanks again.

Jim Key

The earlier brake drum drum is what I am after. I was told they replaced the thrust bearing with 3 washers (.026", .042", .042") to create an .015" to .027" clearance. If 192something is what I am making, then so be it. I based the brake drum off ebay shots labeled 1912-1920 or so. I am not making t...

I based the 1915 on there being two bushings inside the brake drum shaft. Read they changed in 1916. Really no other reason. When did the starter and ring gear begin? I'm not opposed to dating this correctly, or altering the plan to make this correct. As to acquiring a Model T transmission to measur...

Hello everyone, After being away for several years, I have decided to renew my membership and return to this forum with what will hopefully be received as a interesting project, worthy of members help. Years ago I started a plan drawing of the Model T transmission, mostly because I wanted to know ho...