by Daniel Stern
The 1960-63 aluminum-case Torqueflite automatics (A-904 and A-727) used a sealed, disposable canister-type transmission fluid filter as an option in 1960 and 1961; it was standard in 1962 and 1963. These transmissions had a metal screen screwed to the underside of the valve body inside the pan. For 1964, a flat Dacron filter replaced the metal screen and the external canister filter was dropped.
On a automatic Mopars before 1964, the canister filter is clamped to the engine block right at the level of the oil pan rail, a little ahead of the starter motor, with the transmission fluid cooler pipes threaded into (on one end) and onto (on the other end) the filter can.
These canister-type filters are no longer manufactured. New Old Stock items can sometimes be found, but are usually quite costly. You can, though, convert to the superior 1964-up in-pan filter, making future transmission service easier and less costly, without too much trouble.
There are a few different in-pan filters that will physically fit, but on a pre-1966 transmission, you need a filter with two fluid ports in it. The 1966-and-up filter has only one, and if you use it on a 1965 or earlier transmission, you’ll starve the rear pump and damage it; you’ll wonder for a few days what that weird siren-type noise is that increases in pitch with road speed—that’s the rear pump operating with insufficient oil.
For this project, you’ll need:
A 1964-1965 transmission filter (with two ports). The NAPA or ATP № 19715 or 17956 filter/gasket kit contains the two-port filter. Others include Wix № 58656 and Fram № FT-1015A.
A 1964-up transmission pan or a brand-new pan. Nice new deep pans with unwarped rails for the A904 (i.e., the stock A500 pan) are at dealers under part № 52118 779AD, and they even include a spiffy magnet to catch metallic shavings.
Whether you go that route or install a used pan, save yourself current and future hassles by discarding the floppy cork or rubber pan gasket that comes with the filter kit. Instead, Chrysler dealers have a nice double-seal, reusable rigid pan gasket, № 4295 875AC.
These part numbers are for A904 transmissions, which have a roughly square-shaped transmission pan with one corner cut off. The larger A727 transmissions take pan № 5211 8780AD and gasket № 2464 324AB. The doughnut magnet itself is № 3681 601.
You need to change the pan because, when they changed to the in-pan Dacron filter for ’64, they also put in a circular depression to make room for the Dacron filter, which is thicker than the earlier pickup screens.
The new pan is deeper than the original; you don’t need a filter extender, but it’ll take a little more fluid to bring the level up to the “Full” mark on the dipstick. Racers use filter extenders so it won’t suck air under high G-forces caused by extreme acceleration and cornering, but no such heroic measure is needed or beneficial on a street-driven car; as long as the fluid’s at the correct "Full" level, the filter is adequately submerged in fluid and everything’s fine.
When you remove the external in-line filter you’ll have a 6-inch gap in the transmission cooler pipe. There are several different ways to handle that:
As for fluid: don’t waste money on expensive specialty boutique-brand fluids, and don’t be misled into thinking the archaic Type F fluid is somehow superior—it definitely is not. Of all the fluids compatible with a Torqueflite, Dexron-VI (“Dexron Six”) is by far the best, based on design and evidence, not anecdotes. It’s widely available, though you may walk into (and have to walk back out of) some parts stores that stock only “Dex-Merc” (Dexron/Mercon) fluids or “all makes/all specs” fluids that only meet the inferior Dexron-III specification. Dexron 6 is readily available from all the reputable brands, even Mopar, part № 6804 3742AA (for a 1-quart bottle that usually costs more than necessary.
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