I ask because the low reverse band activates in reverse, and engine braking in 1st gear. Not regular drive 1st gear, but engine braking manual 1st gear selection. You won't notice in regular driving, you have to pull the shifter into 1st gear.
The other clutch for reverse (I think, been nearly 30 years) is the direct clutch. But if you have 3rd gear, that works.
See if I can remember my C4 apply chart off the top of my head. 2 clutches, 2 bands, one one-way clutch/sprag.
Drive is the forward clutch applied and stays applied in all forward gears.
1st gear (in drive no other clutches are applied, but the one way clutch is holding. No engine braking. Only clutch apply is forward. All other selections have two frictions applied.
2nd gear is a band apply and it frees up the 1-way clutch that was holding in 1st. Forward clutch and 2nd band.
3rd gear releases the 2nd gear band while applying the direct clutch. Forward and direct clutches.
Reverse does not use the forward clutch, but the low reverse band and the direct clutch.
If you loose all forward gears but still have reverse, you lose the forward clutch pack.
Manual 1st is much like drive 1st, forward clutch pack is applied, the one way clutch is there but not doing anything as the low reverse band is also holding. But not just one direction, it holds both ways. So you have 1st gear on acceleration and 1st gear for engine braking.
If the one way clutch goes out, you can drive away with manual 1st, then shift through the gears once fast enough for 2nd gear. The one way clutch allows engine power to the ground, but not the other way around. Loose it, no engine power to the ground (in drive)
Now if a friction isn't working, it doesn't mean it is bad. It can be the valve body isn't supplying pressure to that clutch. That is where the test ports on the side of the trans come into play. If you don't get pressure, look a the valve body for issues. If you do get pressure, you are looking at a clutch issue.
