?55 to ?56 transmission swap?

[Packard8]

Are there any differences in the 1955 & 1956 Twin Ultras? The ?55 Pat I just got has a nice shiny tranny in it and the ?56 Carib tranny is kinda tired & leaky. Assuming that the ?55 tranny is rebuilt (as it appears to be) and working well, how much hassle to swap the pushbutton system from one to the other?

I took the A/C compressor & bracket off the Pat yesterday?man, what a heavy sucker! I?m sort of torn between parting out the Pat piece by piece or selling it whole without the A/C, motor & trans. It is a super straight rust free California car and would be a good candidate for a Cruise Nite Special with a Mopar 440 & Torqueflyte pushing it around (sorry guys, at least I didn?t say Chebby?.lol).

<img src="http://www.aaca.org/ubbthreads/images/graemlins/shocked.gif" alt="" />

[Guest imported_Speedster]

For SHAME, For SHAME ! <img src="http://www.aaca.org/ubbthreads/images/graemlins/wink.gif" alt="" />

My manual says that there were improvements in bearings, differences in valve body and the way the drive shaft flange installs in '56. If the case of the '55 is Aluminum then it is a later version. I understand both iron and aluminum cases were used in '55.

[Packard8]

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body"> For SHAME, For SHAME ! <img src="http://www.aaca.org/ubbthreads/images/graemlins/wink.gif" alt="" />

My manual says that there were improvements in bearings, differences in valve body and the way the drive shaft flange installs in '56. If the case of the '55 is Aluminum then it is a later version. I understand both iron and aluminum cases were used in '55. </div></div>

Well, close but no cigar.....crawled under and looked, it is an iron case, but a nice shiny aluminum bellhousing & tail. Not sure which way to go now......... <img src="http://www.aaca.org/ubbthreads/images/graemlins/confused.gif" alt="" />

[Mr.Pushbutton]

Stick with the '56 unit on the '56--they learned a lot in that year of production.

[Guest imported_PackardV8]

Does the pan leak oil???? Does ANYONE have a 56 T'Ultra that does NOT leak???

[Mr.Pushbutton]

Does anyone have a car made in the 50's that doesn't leak? All fluids (except maybe engine oil)???

[Guest imported_PackardV8]

probably not. But i would like to reduce the trans leakage at the pan to something alot less than 1/2 quart a month and thats when its just setting still. I've replaced the trans pan gasket twice and yes i streightened the holes in the flange. NOTE pics i posted of the 56 specific pan and trans flange in a recent thread.

[Guest Randy Berger]

Brian, the 56 tranny may have an extra boss/hole cast into it for the

bracket that keeps the shift unit in place. However, there are other

holes cast into the side of the 55/56 case to enable it to be mounted

to a stand for rebuilding. This is pictured on page 10 & 11 of the

Twin Ultramatic Transmission section of the shop manual, figures 15

and 16.

It would be simple to fashion a bracket and utilize one of those holes.

We are only concerned with a solid mounting for the shift unit. The

manual lever control shaft is changed, but if it is same diameter, there

should be no problem. There are some other considerations - did Packard

change the case in any other way for better fluid flow or for any other

reasons? The 56 trans is a much better tranny, if only for the reduction

in weight.

YFAM, Randy Berger

[Packard8]

Well okay guys?.you?ve convinced me that there is no free lunch. I was hoping the ?apparently rebuilt? tranny in the ?55 was an unexpected bonus, as I ?m not aware of any shops in my area that are qualified to do the Ultramatic in the Carib. I believe the front seal is bad in the ?56, as I have to add about a quart every time want to move it around the shop.

I?d rather not part out the ?55 Pat, as it is a really solid, straight rust free example. Hope to find it a good home, but I?ll see how it goes.

[Guest Albert]

I did a friends 55 Ultramatic, whick also had major oil leaks,one from the torque converter, where the drive bolts to the converter. have you check the pan for flatness by placing on a sheet of glass, Also use some sealent on both sides of the gasket, but clean the oil pan & flange with brake clean or thinner so there is no oil at all. have used 3M's weather strip glue and never had a leak, just becomes a pain to remove the gasket later..it also does not tend to squish out as easy.

[Packard8]

Thanks for all the replies. I'll stay with the original tranny in the Carib. Does anyone know of a good rebuilder in the Sacramento/SF Bay area?.

John

[55Connie]

I rebuilt my cast iron '55 with donor parts from a '56. From that experience I can say that most of the pieces interchange.