Engine braking -auto trans problems?
 

As you will see from my sig, I have 3, W123 300D's.
In the youngest, the '84, if I am descending a hill and I shift back to 3rd, I hear the engine RPM rise and I feel the retardation of the engine braking.
On the other 2, when I shift down to 3rd, there is no noticable (audible) increase in engine RPM (no tacho), but I do get some retardation. I have not quantified the differences in vehicle speed on the same hill, but plan on doing so today.
All vehicles drive normally with no flaring during shifts, although they all snatch 1-2 & 2-3 when cold. They all have the same diff ratio.
Is there a problem with the transmission? :confused:

I don't feel like I'm free coasting until 35mph or less, until then the tranny won't let the car just go as it pleases. At this point it is only doing it because it is still in 4th and if I haven't hit the accelerator it sees no need to downshift.

Can anyone help me?

I don't think anything is wrong with them Tony. The tranmission stays connected to the motor until ~55km/h then lightly disconnects if you are in 4th gear. By time you hit 40km/h you should have a nice smooth coast, but if you are in 3rd it'd probably still be connected.