67 290 Flashomatic issue

I have the 290 V8 with Flash-O-matic, last year of the flash-o-matics, the 1967.

When I start the car and put in reverse, when cold blooded, the transmission just has whine and then descends as it wants to shift in reverse. So, I have to let the engine warm up for a bit, 2-3 minutes before it will shift.

Am I on the verge of tranny breakdown? The fluid is pink as pink can be, synthetic, and isn't burnt, AND is at the proper level. Is it the vacuum regulator? Or vacuum leak?

I haven't had it checked out yet by a mechanic.

What happens if you start it and put it in neutral for a few moments? Will it work well once you engage reverse after that?

I ask because what you describe is common with old Mopar transmissions. Start them in neutral, or put it in neutral right after starting and they will drive off with no problem. Stat them and put into reverse and you will wait for a few seconds. It's a problem with the torque converters and age.

I've been starting my '70 Newport that way for years. Filter, flush and band adjustment made no difference. Of course your trans is not one from Mopar, but the same thing might be happening. Worth a check!

If its pink, its got water, and rebuild time. The cooler in the radiator sprung a leak.....

...those didn't have cooling lines that ran to the radiator.  

Not all the old BW trannys were air cooled. It may have lines going to the radiator even if it does have the air cooled converter -- the later models had the fittings for an additional fluid cooler for HD applications (such as towing). The air cooled models have a large opening in the bell on the right side.

If you have a liquid cooler (lines running to radiator) check the water level in the radiator often and make sure you're not losing some coolant. The synthetic fluid may be a lighter red than standard fluid though. If it looks like it just came from the bottle, obviously you're good to go.

Adjustment of the rear band sounds like your best bet. The seal on the rear servo could also be leaking some, but I doubt it is leaking enough to worry about if it goes into reverse after warming up.

You can do a lot to extend service life without a full rebuild. Pull the pan and valve body, thoroughly clean the VB, pull the servos and replace the seals, and replace the shift lever shaft  and rear seal. If you ever pull the trans replace the front seal whether it needs it or not. A rebuilt torque converter would be a good thing, but if it's working good that's an expensive change -- I'd wait until a rebuild and change it. Most shops won't warranty a rebuilt trans with an old converter because the converter may have trash in it that will take out the newly rebuilt trans.