1956 Packard Clipper Transmission

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tdciriello
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Joined: Mon Feb 15, 2021 8:37 am

1956 Packard Clipper Transmission

Post by tdciriello » Mon Feb 15, 2021 9:19 am

I recently purchased a 1956 Packard Clipper. It has an ultramatic transmission. On acceleration until about 40 mph it has a bad vibration and almost sounds like it's growling. Once I get up to speed it goes away. Has anyone experienced this before and know what is happening?

Howard56
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Joined: Mon Dec 24, 2012 11:35 am

Re: 1956 Packard Clipper Transmission

Post by Howard56 » Mon Feb 15, 2021 10:26 am

Depending on which gear selection is made the transmission works in one of two ways. In H the unit starts and stays in high range and depending on throttle opening, will have the direct drive clutch come in to lock out the torque converter somewhere between approx 20 and 40mph. If you have selected the D range, the trans starts in low range and again, depending on throttle position will shift to high range and then into direct drive. If the trans has never had some of the mods or if the throttle position linkage is out of adjustment the shift points can vary, or be very close together or the trans can slip and have engine "run away" between shifts. Wear in the shafts and bushings can also result in pressure losses to various components which can also result in some strange behavior.

It almost sounds as if the problem could be due to an issue when going into direct drive. Direct drive lockout occurs when a clutch plate lined with friction material located inside the converter is applied and in effect locks the turbine sections together providing a direct drive with no converter loss. The result is the same as if you had a standard shift car with a clutch and was driving in third gear. The trans effectively becomes a solid drive line between the engine and the rear axle. If the DD clutch is still the old cork composition and has gotten hot or hardened and glazed it can be slipping and grabbing in a rapid fashion thus causing the noise and vibration. That is a very common issue with aged Ultramatics that may not have seen the best use or maintenance over the years. Worn bushings and loss of pressure could also be an issue where the piston that applies the clutch may not have sufficient pressure to keep the clutch plate tightly engaged.

The next time you have the car out use a gentle throttle and at approximately 20 mph or when the DD tries to engage and noise starts let up on the gas to let the clutch plate engage with no torque being applied. See if the noise or vibration is diminished. If so then the DD clutch needs to be redone and if that clutch is bad there are probably other things that need looking at too. If the noise is not too bad or quickly goes away with the "let off the throttle" approach the car can still be driven -- it is just you will have to put up the what Packard people call a "mooing" sound and will need to use a bit of care when nearing the shift point. The Ultramatic was introduced in 49 and was quite good for its time. You could manually select a high or low range but was essentially a single speed trans with torque multiplication for ultimate smoothness. It was designed around a low torque and low HP inline 8. In the early 50s other mfgs came out with more advanced units so it was given some hurried up mods to the hydraulic operation in late 54 to make it a shift type with two speeds so it could be more competitive. It was in limited use at the end of the 54 production but was then placed behind a high HP V8 with lots of torque in 55-6 and did not receive a lot of testing beforehand. The trans and its reliability with the increased HP turned out to be Packards weak spot those years and needs to be driven with care.

Almost any service to clutches and bands will take a teardown and the average trans mechanic in a reputable local shop will generally give you a fast and definite NO when asked to work on an Ultramatic. That is just as well because the Ultra is such a different unit compared to the Hydramatic, TorqueFlite and other auto trans of that era. Someone not familiar with their construction, operation, wear spots, and quirks can do some real damage when trying to work on them. Depending on your location there are two or three good mechanics still around that are recommended and willing to repair or rebuild them.

tdciriello
Posts: 3
Joined: Mon Feb 15, 2021 8:37 am

Re: 1956 Packard Clipper Transmission

Post by tdciriello » Tue Feb 16, 2021 11:56 am

Thank you Howard for the very helpful information!
I live in Southern California, are any of the transmission mechanics you are referring to around me?
Do you happen to have their names and numbers?

Howard56
Posts: 1283
Joined: Mon Dec 24, 2012 11:35 am

Re: 1956 Packard Clipper Transmission

Post by Howard56 » Tue Feb 16, 2021 12:23 pm

This is probably the best known Packard place in So Cal and has been around for years. Started in the 60s and then sold to the current owner, Robert Escalante, when the founder retired. You might give Robert a call and see what he says. No idea if the virus is affecting the shop but at the moment their website appears to be offline. That could be incidental to the virus though.
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tdciriello
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Joined: Mon Feb 15, 2021 8:37 am

Re: 1956 Packard Clipper Transmission

Post by tdciriello » Wed Feb 17, 2021 9:48 am

Thank you!

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