Packard Forum Index » V-8 (1955-56)

Hello.

I have been recommended to use Dynocat Shiftmatic D3M in my
1956 Twin Ultramatic.
I do not know whether the transmission is overhauled or not,
it is possible as the rest of the car was restored in the US in early/middle 90`s
Has anybody any experience with this fluid?

Rocky46

Speaking from experience, the only fluid I'd recommend in an Ultramatic would be B&M TrickShift.

Never heard of Dynocat.

can you not also use Type F? B&M is like 8.50 a quart around here. type F is 3.50

You can, but I wouldn't. I found that TrickShift is the best fluid for Ultramatics, and I've tried 'em all. Don't buy the synthetic though, it's not needed and the regular stuff is a lot cheaper than $8.50 a quart, at least around here.

I wrote a FAQ, over a year ago, that covers the salient points on this issue.

This way please: ULTRAMATIC: What Fluid to Use

However, I've never heard of Dynocat.

Thanks for your advice.

Rocky46

Somewhere I found a letter from Packard authorizing the newly introduced Dexron (friction modified fluid) for the Twin Ultramatic (and I assume Gear Start).

I assume this was to aid the synchronous shift from L to H when in D.

However, I only use H when driving any Ultramatic because synchronous shifts are the first point of failure in most automatic transmissions.

I believe there was an "Eureka!" posting on this subject in the not too distant past. That posting talked about the friction materials that the bands and clutches have. The correct fluid will depend upon the materials. Different materials, different fluids. Sorry, I do not recall anymore about this. None of my Packards have Ultramatic transmissions so I did not pay a lot of attention to the posting except I thought it was a good answer to the what fluid to use question.

(o{I}o)

Tim -

If you're talking about the original Dexron fluid, you may be right, and this may be why it was once recommended it to me, decades ago time ago.

However, an important additive was eliminated from later formulation - whale oil. I updated my FAQ post, a few weeks ago, to reflect that.

That change could be why some people have reported problems with using modern forumalation of Dexron with transmission that have the original type friction material.

I'm sure BigKev would love to have a scan of that letter to add to the archive - with a note to refer people to the FAQ.