Trouble in the transmission, what's up?

[DanTreace]

Have been investigating today the source of rather disturbing noises from the transmission of my '27 touring.

Noise presented out of the blue on January 28th, had run about 2 miles to a friends home, parked and couple of hours later started fine, ran normal speed about 30 back to the house and on arriving to park in the garage.

But the reverse was very rubble loud. And then when going into low pedal, clutch lever forward, same growl and rattle with jerking and stumble.

Something is wrong in the transmission.

Here is the video made on the day in January, fearing more damage if driving, so parked it, and have later removed the engine to do a " post mortem"

https://youtu.be/nAD98o0fCnE?si=tbNn7mQteuCXdjhF


After reviewing, anyone suggest what is the internal issue(s)?


After a few guesses, of those who wish to , I will post our photo findings made this morning

[Allan]

I once broke a pinion gear tooth off. Going down the road i could hear a faint ticking that others unfamiliar with the car would never have picked. The louder noise only came on trailing throttle. under brakes and when reversing.If you have found yours. it is not a busted pinion gear!

Allan from down under.

[speedytinc]

How long has this motor been in service?
Triple gear issue.
Acts like a seized/seizing triple gear bushing(s).

Before removing the motor, I would confirm thru the inspection cover.

[DanTreace]

How long has this motor been in service?
Triple gear issue.
Acts like a seized/seizing triple gear bushing(s).

Before removing the motor, I would confirm thru the inspection cover.

About 3,500 miles on total rebuilt, all new parts, scat crank, pistons, rings, including all three new repro drums, triple gears, pins, turbo discs, etc.

Did look at triple gears inside the inspection port, nothing seized, loose or rocking at that view.

[John kuehn]

For a time as I remember if you were buying the new drums you could use your own drum gears if they still pretty good. Maybe now you can buy a complete new drum. If you used your own drum gears maybe a rivet or more has gotten loose? Just a guess.

[speedytinc]

In your 27?
Spiral split brake drum shaft.

[DanTreace]

Thanks for the insights on the noise.

Thought too the triple gears, so when inspecting after disassembly, every thing was pretty ok, clutch spring and drum ok, the turbo discs without wear, but when revolving the drums, there was a bit of catch as the brake drum was rotated.

Peaked at each gear revolving and found this

Click on photo to enlarge.

So lifted off the drums and took closer look.

Haven't had this occurrence before, the new driving gear cracked in two pieces, right at the key slot corners. That was the jerky rattle alright!

At least the flywheel recess kept the two pieces together, not sure how long it ran before both sides let go, perhaps the gear ran for a while with one side cracked?

So fix will be to replace the gear with a new one, not sure why this driven gear failed in short time, engine built and put in service May 2022, had about 3500 miles or so on it. Couldn't find a Ford marking on its so guess its a repop gear.

[TXGOAT2]

It may be that the gear was defective, or it could be that a problem in the u-joint, driveshaft or rear axle put a shock load on it, causing a fracture. I'd do some checking on the driveline downstream of the new transmission.

[RajoRacer]

I have a drawer full of good used ones, if you need one Dan - pay the postage.

[Dan McEachern]

You had me worried for a moment, that drvien gear appears to be an original. I say that because of the brinell hardness test dimple that is visible in your picture. Brinell testing is how FORD checked the heat treat on the transmission gears. Hope that helps!

driven gear markup.jpg (29.22 KiB) Viewed 151 times

[speedytinc]

Well, that's a new failure, I have not seen before.
Why?? Is the shaft new with a slight oversize. Did it press on extra hard?

[DanTreace]

John

All the parts were new on rebuild, shaft, drums, triple gears, pins , etc.

Thought the gear was new too, but have looked at other Ford driven gears (worn parts I have) they each have faint script or at least letter marks for inspec or maybe steel type, the busted one had same ‘brushed like” finish on the outer rim but no marks I could see.

So it must be a 100 year old part that just gave up finally….stuff happens.

[Oldav8tor]

I don't have the knowledge and experience of any of the other responders but I have learned to expect the unusual when dealing with Model T's...our club even had a T-shirt made up with our motto: "I Never saw that before..." because we were finding so many strange things when working on member's cars.

The late Rich Eagle graciously let us use one of his paintings depicting a fan blade flying off thru a T's hood. Fortunately that's one failure our members haven't experienced.