FORDS EARLY DRAKE DRUM WITH LUG SHOES
IT APPEARS FORD MADE TWO DIFFERENT EARLY BRAKE DRUMS THAT ACCEPTED THE CLUTCH SHOES.
1. THE 09-24 BRAKE DRUMS HAD SIX INTERNAL LUGS FOR BOTH THE BOLT AND THE CLUTCH DISK. THE 1925 AND LATER DRUMS THAT ACCEPTED LUG SHOES HAD 12 LUGS. 6 FOR THE BOLTS AND SIX FOR THE LUG SHOES.
2. THE FIRST DESIGN APPEARED AROUND 1925. IT WAS A SPECIAL CASTING AND USED A SPECIAL DRIVE PLATE JUST LIKE THE 09-24 PLATES BUT WITH A WIDER BOLT CIRCLE PATTERN. AN 09-24 DRIVE PLATE WOULD WORK BUT THE BOLT HOLES WOULD HAVE TO BE ELONGATED.
3. THE SECOND DESIGN APPEARS TO BE A MODIFIED 26-27 DRUM AND USES A STANDARD 26-27 DRIVE PLATE.
4. ALL OF THE DRUMS HAD THE SAME PART NUMBER, T-709
Yes. The narrow transmission brake drums with lug shoes are rare and it has been speculated they were only used as spare parts sold at Ford dealers during the improved car era intended for earlier cars.
Here's an earlier thread where the records of change are listed for the lug shoes: http://www.mtfca.com/discus/messages/29/16977.html?1179348543
From there we get a date:
"1-26-27, #19616 Specified use from 1908 to 1927, inclusive, instead of 1926 only."
Maybe this means that the new type of narrow brake with lug shoes wasn't developed until late, by the end of january 1927 - so that would explain why they are so rarely seen.
I have not seen one except on ebay and maybe here. The one on ebay got pulled before I got to bid on it, darn!
Ford made a redesigned driving plate for the narrow drum with lug shoes, and Glen has one. The only problem is the part number is the same as the earlier ones, so it's almost impossible to identify one. Ford NEVER used a '26-7 driving plate with this type of brake drum, because the outer edge on the driving plate is part of the braking surface. I have this type of drum in all but one of my T's, and have had to file the holes in all the driving plates to get them to fit, as Ford noted in a service bulletin for 1926. A wide drum can be machined to the correct size by an experienced machinist.
Lee Pierce took a 26/7 brake drum with the lugs and cut it down to the width of the earlier drum. Then he installed it in his 1912 touring. That car is now in Germany, one can only imagine the posts on this forum in a decades time....
Larry, The one I have is as you say. The drive plate provides a portion of the brake drum surface and requires a special drive plate. However,we just bought two NOS drums at Bakersfield and they are of the 26-26 design and have a wider drum surface and use a standard 26-27 drive plate. There is no end to the variables. We learn something different every day
Here is the typical 09-25 replacement drum requiring the special drive plate. Note the part number T-709
Here is the other which is recessed like the 26/27 and accepts the 26/27 drive plate which fits perfectly flush with the extended portion of the drum. Note the part number is still indicated to be T-709.
It is reasonable to conclude the earlier drum was pre-production 26/27. Once the design was incorporated into the new and improved 26/27 designed brake drum, Henry changed the design of the replacement 09-25 drum to the same configuration of the 26/27 drum only reduced the drum width. This no longer required the use of a special drive plate as was required with the earlier version and would now incorporate the use of the same drive plate used on the 26/27 clutch / brake drum.
The following was taken from the MTFCA site encyclopedia regarding Ford's records of change:
"3311B (T-750B) Wider drum using the same gear and bushings as 1925. Steel shoes (3312 (T-754) were added to the clutch lugs. (Later replacements for the earlier brake drums also had these steel shoes.) The large clutch plates (T-728B) were redesigned to fit the new drum. These plates could also be used for replacements in earlier transmissions."
The term "later replacement for the earlier brake drums" implies there may have been more than one design for the improved replacement drum utilizing the replacement lugs.
Makes sense that the replacement drum be altered to accept the 26/27 drive plate. Why have two separate drive plates if it was not necessary to do so. I've never known Henry to have done anything different.
Well, the part number T-709 is also present on all of the 26/27 model drums I have inspected. I guess we will never know if Ford later modified the 09-25 replacement drums to accept the now standard 26/27 drive plate to eliminate the production of two separate drive plates. On a side not, I like the newer design much better as it eliminates the need of running the brake band on a separated surface as was the case with the earlier design. Instead, the band is able to ride on completely smooth drum surface as was not the case before.