Packard Forum Index » V-8 (1955-56)

Studebaker with Detroit gear division of Borg Warner developed a three speed automatic transmission with a lockup torque converter for 1950 which was used till 1955 also used by Hudson International- Divco, Jaguar and Mercedes Benz

studebaker-info.org/text3/dg250.txt

That's what I get for being a Packard nerd, learned something today. My comment on improved mileage still holds

I have 2 55 Clipper Custom Sedans. One has the Chrysler 727 transmission and one is still has the original Twin Ultramatic. Both are doing fine. I just replaced the flex plate on the Chrysler one after 50,000 miles. The original one I just got and the transmission is doing fine. I would have kept the 1st one original but the transmission mechanic said it would cost the same to convert it as to rebuild the original. He was wrong, but I have been enjoying both cars. I do miss an overdrive, but I enjoy driving either car. I also miss disc brakes, but that is discussed in another thread.
If I had to start over with the first one, I would have had it rebuilt.
I think there is a Packard manual transmission with overdrive that would bolt right up and give good gas mileage, if that is all you are looking for. They are hard to find, but they were built.

A small mathematical thought on economy. My experience with countless miles of driving these mid fifties barges that have all the aerodynamic qualities of a barn door is that on the highway you can get oh maybe 17 mpg on a good day if you don't push it too hard and stay under 70. Both my 56 Clipper with TU and 3.07 rear and the 51 200 with overdrive (2.95 cruising ratio) do about the same.

But lets say a Patty is only churning out 15mpg. Now by some transmission miracle you get it up to 20 mpg. That saves 4.2 cents per mile based on $2.50/gallon gas.

It will take you slightly over 60,000 miles to pay for a $2500 trans conversion, if you can get it done and in the car for that much.

acolds wrote:

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Yet, IIRC, with the 'D' position selected on those cars, the trans started off in second gear - so, just two-speeds plus lock-up, in common use.

Actually, the performance of that DG transmission wasn't that much better than Ultramatic. With V-8 the unit turned 0-60 in around 19 seconds, while with stick shift the car turned 0-60 in 12.8. The curb weight was 3000 pounds.

Thanks for all ...

This is indeed the big problem : find anyone who's could repair the Twin Ultra, here in Europa.

I have an other 56 project car, and for this car, I thinking about a 1956 Cadillac engine and transmission (if engine could be fitted into the 56 Packard) ... and the transmission command will come from a Rolls-ROyce Silver Spirit, witch use the GM transmission with an electric motor as shift (so, could be electronically controlled from push buttons) ...

Any connoisseur who's confirm (or not) the 56 Cadillac engine could go in the 56 Packard (why, you will say ... because the car have no more engine and trans).

The physical size of the engine will be OK. The Silver Spirit Hydramatic would be 1990 and up, that transmission is not the same as a 56 Cadillac Hydramatic and probably would not be compatible.

An interesting thought on the RR shift actuator. No idea how plentiful or expensive RR components are in Europe but over here the few on ebay are fairly expensive -- $200 and above. For anyone contemplating installing a GM trans in a 56 it might be worth picking one up but it looks bulky so would have to be verified if there is space available and it would mount to the GM 700R4 trans case. The actuator mounts off side to the actual transmission shift lever and motion is transmitted to the transmission portion by a rod using a standard clevis and lever arrangement at both ends. If it fits, it looks to be a rugged unit and might be more robust and reliable than the Packard actuator but if the shift detent and spacing is different then it would have the same issues as the Packard actuator.

The electrical looks to be very compatible with the Packard pushbuttons. The RR uses a finger and segment arrangement almost identical to the Packard. The big difference is the RR motor is a permanent magnet so their segments select one of two relays to reverse polarity and determine which lead is grounded and which gets power. The Packard motor uses a field winding and uses its dual relay to change the relationship between armature and field. The RR relays appear to be built into the actuator case so it may be just a matter of running a few wires for power and to connect the push button wires to the RR fingers and removing the no longer needed Packard relay. Reverse lights and Park-Neutral start interlock could stay Packard. Not sure what the RR uses in place of the pressure switch to prevent accidental shifting into park or reverse while in forward motion but that would have to be sorted out.

Since the RR actuators are expensive and not growing on trees, just seeing that arrangement makes me believe more than ever the Packard motor could be adapted by casting a new finger block out of urethane plastic to reflect the different GM layout and spacing. Machine a shaft to fit and attach to the sector gear and then add a lever on the end with a rod to connect to the GM lever. A new mounting plate to support the new shaft and place the Packard assy in the same location as the RR should be relatively easy. That way the entire Packard electrical portion could be kept intact.

If I had a 700R4 transmission I would give the bench work portion of adapting the actuator a go but trying to haul a trans out of a junkyard or buying a rebuilt and having it shipped out is no longer feasible because I know I would never get around to installing it.

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Thanks for theses additional informations