Packard Forum Index » V-8 (1955-56)

Hence my breakdown on the Pa turnpike on Friday; well I have come to the conclusion than a conversion is definitely in the game plan for me. No more twin-Ultra merry go round.


DEFINITION OF INSANITY:
Performing the same action over and over and expecting a
different result.

If the reactor is stuck then wouldn't the top speed be limited to 50mph. With Ultramatic, the theory was higher takeoff ratio via converter vane angle was made possible by virtue of direct lockout clutch. Thus, only if DD is not working would such a problem occur. No?

That notwithstanding I think poor Wauhop has paid enough for poor results.

One other note here: Bypass the old cooler and make sure there is no binding somewhere in the driveline. I'm sure the rebuilders checked that already, but you never know.

I heard stories of dealers doing unit replacements because their rebuild attempts yielded failure.

In convertors the reactor turbine should start to spin along with the pump and driven turbines as driving speed is reached. Torque multiplication has ceased and the unit has become a fluid coupling. You are right, Tim, because Ultramatics had such high multiplication (I think up to 2.7:1 in the 56s), when they had reached coupling speed they slipped rather much, thus the direct drive was a good idea. Dynaflows also had high multiplication, slipped a lot at coupling speeds but didn't have the direct clutch. I have heard that Buicks with early Dynaflow were not allowed to drive up Mt Washington.

Anyway, if the freewheel clutch for the reactor turbine jams, and they often do, that turbine will be sitting still in the middle of all that rotating fluid. You can imagine the turbulence and heat. All the driver will notice is that the car feels a bit sluggish and just presses the gas down harder. The direct drive clutch will engage just like normal until the fluid gets really hot.

Once that reactor clutch has jammed--one or more spags flip over--it never unjams.

So has there ever been discussion on an replacement/ upgrade to the reactor clutch?

It seems from this discussion to be an issue. Yes, we an change out to another transmission, but can the Twin-Ultramatic be refined, like some did with the oil pump on the V8?

Ross writes:
"Once that reactor clutch has jammed--one or more spags flip over--it never unjams."

Ok. But suppose the sprag was installed backwards upon rebuild. Would that cause the same problem of overheating or maybe the trans would not operate at all?????

Cars with automatic transmissions were not allowed up Mt Washington because the automatic couldn't hold the vehicle back when descending the road up Mt Washington. Standard trannys could be put in second or even low gear. I believe that lesson was learned the hard way.

Well Ive made my decision when I get the Money together im going to go with a Bendtsen conversion to a Chevy 700r auto-when its completed ill let everyone know how it turns out (probably next year).

SOmeone correct me if i am wrong (probably am) but the DynaFlows had NO resistence to deceleration whatsoever. I think had something to do with sprag clutch. And the brake linings of the car were VERY unusualy thick???

My Bendix brake data shows Dynaflow-equipped Buicks with the same brake lining thickness as the non-Dynaflow Buicks.

Since Packard was the only automatic with a direct drive clutch, I suspect theirs was the only one that provided significant engine braking.

I agree with Ross. The reactor is on a fixed shaft and during lock out should freewheel same as coupling phase. So the question is what is causing the problem. The answer to that is probably as expensive as the conversion.

I've heard that insanity quote (even from learned types) a million times and disagree. Insanity is demanding unreasonable results from a given action. Expecting different results from the same action is ignorance. For example: Some nut tries to impress a Hollywood actress by attempting to assassinate the president. That's insane.