Packard Forum Index » V-8 (1955-56)

According to Hydramatic coupling phase of the Hydramatic was achieved only few miles per hour later than with a torque converter, but that fluid friction was reduced and efficiency higher than a torque converter during coupling phase.

When they are adjusted the first shift is barely felt. I love the Hydramatic. When they are working right, they have wonderful shift quality.

Bear in mind that I am talking about the traditional Hydramatic and not those gerotor units and stuff that came later when GM was trying to re-engineer the thing. An interesting aside is that in comparison testing the Hydramatic actually outperformed the Torque-Flite in straight line acceleration.

It's too bad the Borg-Warner transmissions aren't usable given the Ravigneaux geared units (Fordomatic two speed) worked the same as the Ultramatic and the three speed units did the same if you started in D2 range. I wish my modern car had that D2 feature because it was really good for snow.

Quote:

When you speak of the throttle pressure setting, are you referring to the linkage adjustment on the carburetor or the pressure adjustment screw on the valve body?

It sounds like you recomend an auxiliary oil to air cooler to increase the lifespan of an Ultramatic.


What mileage do you see most Ultramatics fail or need rebuilt at?

The throttle pressure adjustment on the valve body was only to set the baseline idle pressure so that Packard could give standardized instructions for setting up the trans. In practice it is utterly unimportant as you can do everything you need to do with the adjustment next to the carb.

I recall seeing a few cars where adjusting the throttle pressure had an erratic effect. That was caused by operating levers being loose on shafts and binding linkage--usually the throttle rod being bent and rubbing on the bell housing. At this late date and with a lot of ham handed mechanics involved in the past, everything has to be looked at closely.

I prefer an air cooler. A water cooler is nice if the car is being operated in sub-zero temps and needs something to actually warm the trans when ice cold. That is not usually the case these days.

Mileage to failure is not predictable--there are too many factors involved. But here in the 21st century I never get cars with virgin TUs anymore. They have all been diddled to some degree. That is not remotely surprising------how is any elastomer seal supposed to last 67 years?

Great care in doing the work is a necessity. I spent considerable time fitting bushings given shaft wear needs to be compensated for.

However, another consideration is the conditions of the nation's roadways. Rough roads are very hard on drivetrains. The computer controls in modern cars have programing that compensates for such. Otherwise, the check engine light would be setting misfire codes. When I drive in a state with good roads, I get significantly better mileage than here on Michigan's dilapidated, broken down, neglected, gas tax starved wagon trails. At work one of the guy's transmissions went before he needed his first brake job. No doubt from the strain of using broken down roads. And almost all of his commute was on the highway.

Is the key to long Twin Ultramatic life in proper maintenance and adjustment, or is it in always driving in high range with a light foot?

I'd rather not be a slow slug in the right lane all the time to save my transmission, but if that's what I must do...

I always use drive (right hand position)as it gives the torque convertor less work to do with consequently less heat generated. As long as the shifts are clean there is no excess wear and you can drive it as hard as you like. Once the trans is in direct it doesn't care at all how fast you are going.

I dont baby mine. If gas comes down ill have ross check mine out.

Pac meet

75 80 is cruise speed.

With the 56 spring mod. Off the line way better ..

I use both H and D.

But since ross said D is better
I'll use it more.

Diffidently on a hill. D.

Good to hear. You've been very helpful, Ross. Thank you.

Driving in "H" for you 1956'ers or (^D) for us 1955'ers isn't very pleasant for me at my 7000 feet above sea level. Any naturally aspirated engine is down on torque by at least 23% up here, and lugging a 4600 pound Packard off the line with nothing but a torque converter is not much fun when you are missing that much torque.

There is no doubt that these cars have plenty of thrust once they are out on the open road. The Packard V8 is one heck of a low RPM slugger. There is a long and steep 65 mph highway grade near my house that climbs up to nearly 8000 feet. It's a good road test for engine power. My Packard has no trouble on it. I was really impressed the first time I did it. Even the most powerful cars feel that grade.

RH for country driving it doesn't matter much because you are in High gear almost all the time anyway.

Only for stop and go driving, or if you are going up steep hills at low speeds, is there a significant difference where you will be building up extra heat in the torque converter if you have the car in High, when it could be in Low instead.

Ross's point is well taken because with the increase in power the transmission wasn't changed that much so it was like putting a 120 trans behind the V-12. But the trans needs to be in good condition to use Drive. I was never a lead foot with those cars and I always accelerated moderately until the thing got into direct. Then I would gradually increase the throttle. It's a habit I never got rid of and still use it with my modern car.