Packard Forum Index » V-8 (1955-56)

I was thinking of changing out the trans fluid in my 56 pat even tho it shifts properly and it doesn't smell burned or discolored. I've had it 3 years and don't know when it was changed or what routine service was done prior to my acquiring it. I've heard stories of people having problems after changing their trans fluid and had none prior to changing it. What has been the experiences here.

The Ultramatics originally called for "Type A", which may be NLA.

Some sources cite GM's "Dexron" as being a suitable replacement for "Type A". However, while the characteristic of "Dexron" are allegedly closer to "Type A", some owners have had better results with "Type F". In fact, some who have used "Dexron" reported a groaning noise from the Direct Drive clutch at part throttle, under light loads (which you can "drive" around), but this noise cleared for those who drained and refilled with "Type F".

I think the general consensus is to use "Type F" if your Ultramtic has not been rebuilt or still has OE clutch linings, but use Dexron if it has been rebuilt AND upgraded to GM friction materials.

Someone correct me if I am wrong.

I don't know if that's the general concencus or not, but I think the recommendation is valid. I'll note, however, after a rebuild I went to Dexron, had the groan, changed back to Type F (actually, Type FA) and have had 13,000 miles of flawless performance since.

Try B&M Trickshift, it's what I have in mine, and I have had zero problems with it. IT sat in a field for 40 years before I got ahold of it, and all I've done to it is put in a new converter seal, drop the pan and clean it all out, and change the fluid. It'll probably last another 68,000 miles.

Thanks for the info. I think I'll try the FA even though I have no clue as whether the trans was ever rebuilt or ever had repairs to it. I notice it leaks a little fluid (Wet spot under the car)but the fluid level remains OK.

Some leaks are inevitable with any automatic tranny that old.

While most are minor annoyances, you should pay particular attention to any leaks coming from the front pump seal. That could be warning of an imminent seal failure that will leave you stranded. That's exactly what happened to me with a Patrician I purchased that was billed as "drive anywhere".

While removal of the transmission and converter are necessary to replace the front pump seal, but a full teardown and overhaul is not (usually) required.

For the last 16 years I have worked in two museums, each with collections numbering in the 200+ area, with vehicles from the dawn of time until the present. It has become my opinion that any car made between 1953 and 1980 is BORN to leak unless started and run weekly. If the trans doesn't leak the power steering does. Sometimes both, and the differental leak. A freshly rebuilt trans with new seals stands a good chance of keeping its fluid.

You think a couple of little drips is annoying? Have you ever seen what a Bijur-equipped car can do to a garage floor after 40 years?

newpig.com/en_US/main.jhtml?catId=2LHBPI ... ALMATPADS&page=browse/capture.jhtml these guys are very handy to know when you are around old cars.

Turbopacman wrote: "Try B&M Trickshift, it's what I have in mine, and I have had zero problems with it. IT sat in a field for 40 years before I got ahold of it, and all I've done to it is put in a new converter seal, drop the pan and clean it all out, and change the fluid. It'll probably last another 68,000 miles."

I, too, have had good service from B&M Trickshift. My car ('55 Pat) regularly makes the trip from Orlando to Miami and back at typical Florida's Turnpike speeds.

My transmission, although shifting, was very balky and the direct drive clutch would sometimes slip when I got the car four years ago. Taking the pan off cleaning filter and the gunk out of everything and refilling with, first, Dexron and, second, Type F made shifting smoother but, under acceleration, the direct drive clutch would sometimes slip. The Trickshift (about 2500 miles ago) made an instant improvement and slippage has stopped altogether. I put this stuff in a VERY used '57 Pontiac Star Chief, some 30 years ago, that wouldn't even move and drove it for another two years. Trickshift is one of the few products that lives up to at least part of its advertising.

If you use it, however, I recommend the original, "dino-juice," formula - NOT the synthetic. The synthetic variety is reportedly engineered for modern (post 2000) transmissions and does not firm up shifting in old transmissions as well.