Sunshine,
no, I never tried to shift a 1963 Dodge anything.
But, just the same, you’re quite correct about the worn 1-2 synchronizer. A worn or broken forward gear synchronizer blocking ring will certainly cause clashing during an attempted shift. I should have said a worn REVERSE synchronizer doesn’t cause clashing gears.
My apologies for the oversight.
As I recall the old GMC and Chevrolet 4 speed truck transmission shift patterns showed L-1-2-3 with L being compound low. And LOW was very low. In Low the driver could pull out the throttle and jump out of the truck, walk along side then jump back in the cab. When picking up hay a good driver was in and out of the cab often seperating bails ahead of the truck. Those 100 horse power I-6 engines were taking a beating to pull 3 to 4 tons of gross weight.
We had a 51 Hillman Minx with a compound low gear. Only needed when you had a full load. And it was certainly not something you ever engaged when you were moving.
I should have said a worn REVERSE synchronizer doesn't cause clashing gears.
Then why would any manufacturer go to the trouble of synchronizing reverse??
Sunshine
P.S. Anyone else refer to a compound-low as a “granny gear”?
I just remembered a transmission design that had a Reverse synchronizer of sorts. IIRC it was on a Tremec T-5 transmission. Since 5th gear was in the opposite side of the gate for REVERSE, the 5th synchronizer/clutch sleeve was used to brake the counter gear cluster and as result the clutch disk. The synchronizer/baulk ring worked against a coned surface keyed into the tail housing. When the synchro/baulk ring allowed the dog clutch sleeve to progress, the REVERSE idler was engaged with the main shaft REVERSE gear. This would not prevent clashing if the vehicle was moving but it did allow clash free engagement of REVERSE otherwise i.e. if the clutch was dragging or if spin down was extended.
@JayWB. My experience with a broken synchronizer/baulk ring is that there was complete blocking of engagement of that gear. As the split synchro ring slid up the tapered surface of the gear, the split would open wide completely blocking some teeth of the dog clutch sleeve. No normal amount of force could get the sleeve through the synchronizer teeth. The only solution was to replace the synchronizer ring.
I had a friend years ago with a Corolla 5-spd whose clutch went out (would not release) 100 miles from home. He said he made it back by trying not to stop, but when he had to, he got going by forcing the car into first (basically using the 1st gear synchro ring as the clutch).
The clutch cable on my Vega broke once. To start in first gear…I stopped the car…turned it off…then let the starter start the car. Worked fine (except on a hill). Only had to drive this way to the parts store to get the cable.
You know what I’ve discovered? I don’t know the first thing about what’s inside manual transmissions … lol …
Seriously, the only way I’d understand, I’d have to see the parts you folks are talking about right in front of me on a work bench … but it is fun all the same … 
And different trannys have different synchro designs. A Chrysler 3-speed was very different than the Ford Dagenham 4-sp I worked on. Kinda had to, I split one of the baulk rings…
But the old 3 speeds were somewhat easy to repair and they were so basic and mechanically logical and easy to understand. The most difficult problem for me was getting the needles tucked in. Patching up worn out column shifters was more tedious than repairing the transmission.
Sunshine,
I’ve never seen a manual transmission with a synchronized reveres gear, using the word in the context that involves a blocking ring with the intent to eliminate clashing.
I’ve seen transmissions that use a synchronizer for reverse because if there are an odd number of forward gears it’s cheaper and easier to just use the synchronizer for the odd gear for reverse. That’s why in some transmissions you move the shift fork forward for fifth and then back for reverse, or forward for reverse and back for first.
Researcher,
I can imagine how a blocking ring that has a section completely broken off would cause clashing, and badly worn blocking rings will definitely cause clashing, since they don’t function at all after they’re worn badly enough.
I've never seen a manual transmission with a synchronized reveres gear, using the word in the context that involves a blocking ring with the intent to eliminate clashing.
Now you have; used on thousands of Civic 5-speeds:
Sunshine
No, I don’t think I have.
insightful: Ooh! Ooh! Hand raised. I remember “Granny gear”.