COM Shifting Points ??

[ricklove]

Had the COM professionally rebuilt on my 126k mile 1963 Landau. What typically are the shifting speeds from 1st to 2nd, and from 2nd to 3rd? Under "regular" driving conditions, mine seems to shift into 2nd around 10 mph, and into 3rd around 35 mph. If I don't come to a complete stop around 5 - 10 mph, it stays in 3rd unless I "gas" it enough to downshift into 2nd. Normal??? TIA!!

[Karl]

G'day.
Mine shifts into second very early, even then it is hard to tell it has actually changed. I have never checked the speed into 3rd but it is not long after 2nd.
yours sounds much the same as mine.
Karl

[RedBird64]

Sounds normal to me.
With only three gears, they use the torque of the eng a lot. Coming from a modern car with a lot more gears, it always surprises me how it lumbers around the neighborhood in high gear.

[Gagarin]

I thought that it was just me.

I can hardly note the shift from 2nd to 3rd and it seems to go immediately to 3rd? It sure seems to run a high RPM on the highway but it is certainly not a modern trans with 6-10 speeds? I had some work done on my tranny last year so I was thinking that I may have an issue with shifting but it seems to be fine until you wind it up on the highway. It has been so long since I have had an older model with an auto trans I most likely forgot how they act?

Thanks

[RedBird64]

It does run high RPM's on the highway because it has no overdrive.

[GeoffInCarlsbad]

I see this is an old post, but these problems persist. My 1961 had shift points at 8-10mph and then at 18-25mph depending on my drive conditions. this is well within the specs outlined in my 1961 TBird manual.

However, for some reason, after I had changed my Transmission oil and filter, fixed by shift shaft bushing, my shift points are way out of whack. now I go from 1-2 at about 25mph and don't get to 3rd until 55mph. How did that happen?

First this I checked was to make sure I had the right amount of oil in there, and I do. Then the manual has a series of checks to make, starting with the transmission control pressure and engine vacuum. My engine vacuum is just about 18psi, so I am good there.

Has anyone use a pressure gauge on their transmission?

Anyone have some suggestions on why this is happening? I am going back to the manual to begin the diagnostics, but could use some advice from someone who has done this. By the way, I just rebuilt my 390 in my garage. but the issue was already occuring.

Any help is always appreciated.

[Rusty57]

Just a crazy idea to consider. When you changed the shift shaft bushing did it alter the kickdown linkage adjustment?

[jtschug]

The vacuum modulator controls the 1-2 shift, and sometimes these are adjustable, and they also fail a lot.

Make sure the vacuum hose to the modulator is hooked up properly and not leaking. If it is the adjustable type, you can try adjusting it with a tiny screw driver. If not, then replace it with an adjustable.

[bigbrownpilot]

I adjusted my vacuum modulator- turned the internal screw counter-clockwise until it was almost flush with the opening in the nipple. I get a 1-2 shift around 20 and a 2-3 shift around 40 under normal acceleration. Wide open, around 30 and 50. Seems to work well for the way I drive. You might try that before you spend a lot of money chasing something down.