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Re: 1956 400 Ultramatic Transmission Questions
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Forum Ambassador
 
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Unlike the earlier Dexron fluid which was designed to allow more slip for smooth engagements in GM transmissions of the time that used a different type friction material than the cork used in Ultramatics, those who have used modern Dexron III say it seems to have additives that compromise between the old Dexron and F type fluids and will allow a satisfactory grab. It seems to work just fine in Ultras particularly if it is one has been rebuilt with bands and clutch discs which have been relined with modern materials now available from our vendors.
For years type F was the closest modern equivalent to the original 50's specification for the type A fluid Packard used. It was recommended for use with the cork linings so they had a quicker grab to better avoid slipping and possible burning. It provided a much firmer grip than the Dexron of the time. A few years ago a fluid started to be advertised by one of the old car vendors that was supposed to be the same spec as the long obsolete original type A. Fairly expensive, I don't know if it is still around or if anyone tried it in their Packard since type F seemed quite satisfactory. Trick Shift is used by the racing crowd and is a lot like type F but has additional additives which the descriptions say conditions the lining material and changes the grab characteristics of the clutches and bands for a fast and more solid engagement. Those who have used it say it seems to help the old hardened or glazed cork direct drive clutch engagement be a bit better and quieter but is more expensive than type F. With a rebuilt trans using modern friction materials it is unclear if it makes any appreciable difference to be worth the added expense. I don't know if or when Ross is back from his trip but he will probably have some suggestions if the throttle linkage turns out to be OK.
Posted on: 2021/2/25 10:14
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Howard
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Re: 1956 400 Ultramatic Transmission Questions
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Home away from home
 
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Okay. Two things to consider, especially in light of all the modifications and swaps:
1.) I'm going to presume there is no pushbutton shift on this particular Four Hundred. Right? Or wrong? Was it originally the way it is now? Or was this changed since new? 2.) Most people don't seem to know that there were two different shift arms on V-8 Twin Ultramatics. One arm was used in 1955... the other on 1956 Ultramatics WITH selector lever and without Pushbutton shifters. I have seen numerous occasions where a Pushbutton trans was converted to selector lever using a 1955 arm. BAD idea since this conflicts with all the rest of the linkage design and adjustment for 1956. You can adjust the linkage until the cows come home and never get it right. ONE of the big reasons for the change was to avoid the linkage dropping into the "straight-arm position" and thus allowing what appeared to be the transmission supposedly locked in Park position (it was the linkage that was locked–not the transmission). Furthermore with a kittywhampus linkage arrangement, the transmission is certainly going to shift oddly. Something to consider and an area you will certainly want to inspect so see what you have going on there.
Posted on: 2021/2/25 11:52
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Re: 1956 400 Ultramatic Transmission Questions
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Quite a regular
 
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Quote:
Here is a picture of the lever on the side of the transmission. It seems to be tight. It’s not loose. Attach file:  7D4419E9-2DBE-4A4F-973E-35563AF5B28A.jpeg (276.43 KB)
Posted on: 2021/2/25 12:55
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Re: 1956 400 Ultramatic Transmission Questions
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Quite a regular
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Quote:
The car was originally a push button, but the previous owner changed to a column shift sometime after it was restored in 2003. I still have the original push button column and parts, as well as four more push button units and columns. How can I see if it is the wrong linkage or the correct one?
Posted on: 2021/2/25 13:02
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Re: 1956 400 Ultramatic Transmission Questions
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Forum Ambassador
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Look at the gear select linkage on the drivers side when in park. In park the old lever and rod setup will have the end of the lever on the side of the transmission almost flat or at most 5 degrees or so up from horizontal. With a bad adjustment or if slop developed the lever end could fall down or even go below horizontal so the linkage was trying to push in a straight line.
The new lever has the setscrew in a different position so when in park the lever end is around 15 or 20 degrees up from horizontal. The long rod connecting to the bellcrank was also changed in length to accommodate the new lever position. While it might be difficult to connect and even more so to adjust, it could be possible there is a mismatch of parts. If that were the case even though the dash sector label might indicate one gear the transmission might be in another. One other issue that has developed is the lever on the inside of the case the outer lever and shaft connects with is held by a setscrew. The inside lever is pot metal and threads for the setscrew can strip allowing slop to develop. The inside lever moves the manual valve in the valve body and any slop could also result in the driver indicator reading one gear while the trans is in another or even halfway between gears. Slop can usually be determined if you can wiggle the operator lever more than a very few degrees before it seems to drop into a detent. If you can move the lever a fair amount then disconnect the long rod at the trans lever and try to move the lever manually. In any position other than park more than an eighth of an inch or so movement at the rod end would indicate excessive play inside. If the trans lever is solid but there is excessive motion at the inside car lever look at the bellcrank assy for loose bolts or deteriorated rubber bushings.
Posted on: 2021/2/25 13:22
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Howard
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Re: 1956 400 Ultramatic Transmission Questions
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Quite a regular
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Quote:
Here is the selector lever on the side of the transmission. It looks to be at an angle. I can’t feel any play in it. Attach file: C479AD23-332B-46D5-BF39-32C6328A61FB.jpeg (88.54 KB)
Posted on: 2021/2/25 13:40
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Re: 1956 400 Ultramatic Transmission Questions
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Forum Ambassador
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The lever looks like the correct item but unless there is something I am not seeing with photo orientation it does not look like the car is in park -- more like in reverse. As I recall, when in park the lever and rod end should be pulled toward the front of the car.
That park position was the whole issue in needing to revise the arrangement. When the old lever was pulled into park position the end was almost straight with the rod or even landed below horizontal. The rod could not push the end of the lever to have it start moving toward the other selections.
Posted on: 2021/2/25 13:49
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Howard
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Re: 1956 400 Ultramatic Transmission Questions
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Home away from home
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Pull the cotter pin. Pulling back should pop into park.
Posted on: 2021/2/25 19:37
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Riki
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Re: 1956 400 Ultramatic Transmission Questions
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Quite a regular
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The transmission is in park. I haven't had any trouble with getting it in or out of park. I don't know if this is related or not, but the indicator on the dash doesn't exactly line up with what gear it is in.
Also, I moved the linkage to the middle hole today and moved the linkage about 1/8" back, and that did not make any difference. It is still close to the front. I read somewhere where it is close to the middle of the threads usually. Should I adjust it to the middle of the threads? The throttle linkage coming from the gas pedal is 3 1/2", so that seems to spec. The transmission still seems to be slipping when you hit the gas. It seems like it starts slipping instead of going in to the torque converter locking or going in to the next gear. It seems to do this no matter if it is in high, drive, or low. The transmission was rebuilt and installed in 2009, but sat from 2011 to 2021, due to previous owner being in bad health. It only has 500 miles on it at the most. I wonder if something could be sticking from sitting?
Posted on: 2021/2/25 19:47
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