The transmission book says that the face of the triple gear bushing should be .006 to .010 in clearance from a flat surface,is this at least this much ? is more better ?, i am reassembling a transmission and the bushing face has not been turned down.
If you put much more than .010 you will have difficulty putting the spacers in the inner clutch drum. It will push the drums back and make the clearance between the brake drum and the inner clutch drum too tight.
I think .005 to .007 is about right.
Too little and the gears will hit the flywheel with all the slop you put in the "running clearance".
You need do nothing to the thrust surface of the new bushings. Just ream the bushings to fit the pins and give them enough clearance and you will be fine.
Perhaps that is true of the latest ones available, but when I built my TT transmission, the flange of the bushings was too thick and caused the exact problem Steven mentioned above. I just chucked them up in my lathe and faced them off. Problem solved.
The triple gear bushings I bought 25 years ago have the same face thickness as the ones I bought last year; .15".
When installed they extend out .035". Is this the value that should be .010" maximum in order to avoid crowding the drum bearing clearances?
I'm not going to profess the what and how to rebuild a transmission as that is almost like discussing Kevlar, or a water pump, or a distributor.
What I will offer for historical reference is what Ford called for as the original manufacture. Most miss it on the actual triple gear drawing as they wouldn't expect it to be there in the first place...but the Ford value (borrowing Eric picture) is shown below.
Others may offer reasons as to why it should be more or less.
I have maintained and repaired my Model T for almost 40 years now, but I can't profess to knowing a lot about it. I have read the Model T shop manual, service bulletins and the MTFCA transmission book but I never realized this measurement existed.
So I am glad Rick Goelz asked about this subject and brought it to my attention. Thanks to everyone for your input as well.
This is one less thing to go wrong when I reassemble my transmission! :-)
It becomes readily apparent when the transmission turns freely until you install the clutch drum and then it locks up tighter than Dick's hat band.
Who was Dick and why did he buy such a small hat ?
Seriously though, I've always wondered about that expression ;o)
Is it Regional ?
I rebuilt the engine 25 years ago. The only transmission components I replaced at that time were the triple gear bushings but without any machining down of the faces.
The engine ran quite well and could reach about 38 mph but always did feel as if there was something holding it back, especially when warm. Additionally it was impossible to push this car by hand, as if it were glued to the ground.
I'm hoping that the triple gear bushings with their proper clearance will give the car some "zing" that hasn't been there since the engine rebuild. This is getting exciting!
"Who was Dick and why did he buy such a small hat ?"
Richard (Dick) Nixon?
Hal, and Ken are right, if you do not set the gear height, the triple gears do not set at the same height as the drum gears, and will force them selves to be a thrust against each other.
It can wear all gears bad, because of the bind.
We set at .010 over outer edge of the triple gears.
With a straight edge and a feeler gauge check the flywheel at the pin for ware. This ware, if any, should be factored in when setting the height of the flange.