Changing Automatic Transmission Fluid

Voyager transmission fluid change and band adjustment

Lane MacFarlane wrote:

I changed the fluid and filter, and adjusted the bands on our 85 Voyager (2.6L, A470 3-speed, 118,000 miles). The fluid was no longer bright red, but tired dark reddish brown. No burned smell, no flakes, no particles, so that's good! I suspect (as the second owner) this is the first transmission fluid change it's ever had.
The purpose in posting this note is to encourage anyone with an A470/A413 (3 speed 2.6L or 2.2L) to change the fluid and filter if they think it's time. No need to pay someone else $35 to do a half-hearted job! It's a simple, uncrowded, easy to maintain design, and if you can do a valve cover gasket on an overhead-cam engine, you can do this (in my opinion).
Get that new ATF 3+ (Chrysler MS-7176, US$3.50 at my local CPJE emporium, get four or five quarts), get a real MoPar filter for US $7.95 and rubber gasket for US $1.70, and do it! [Editor’s note: in the years since this was posted, in the 1990s, Mopar moved to ATF+4, which is acceptable in the older transmissions.]
You'll need a decent torque wrench capable of reading down to 40 in-lbs for the band adjustment and up to 175 in-lb for the pan bolts, and a factory service manual or equivalent for the torque and backoff turns figures, but that's something most of us have anyway. Also, you'll need a Torx (TM) -type screwdriver (like the one used on the headlight housings) for the filter screws. The fastener sizes quoted are for the 1985 A470, other years may be different.
Watch out when you pull the pan, don't damage the sealing surface prying the pan off (do it gently and you'll be OK, it'll sort of jump loose all the sudden). Getting a premium gasket and sealing agent (if called for) is worthwhile.

Adjusting the low/reverse band is easy, you'll have to remove the parking sprag pushrod (e-clip) to gain access, then loosen the locknut with a 13mm open or box end or socket. The adjusting nut is a 6mm hex (I think that's what I used at least), torque it down carefully to the FSM spec then back it off the number of turns specified in the FSM. I painted two stripes 180 degrees apart on my 1/4" to 3/8" adapter to see when I'd gone 1/2 and one full turn.
Hold the adjusting hex when you tighten the locknut so it doesn't move. Don't forget to put the parking sprag pushrod and e-clip back in! Adjusting the kickdown band is also pretty easy, it's on top of the case under the throttle cable. It uses an 18mm locknut and an 8mm hex adjuster. Use an 18mm box end to loosen and tighten the locknut.
Clean the pan and case gasket surfaces thoroughly and gently so as not to gouge the aluminum of the case...a wire brush worked OK on the pan itself. Don't forget to put in the new filter and filter gasket! Clean the old residue out of the pan, and clean the magnetic residue off the ring magnet in the pan. Might as well do the differential cover gasket, too, since removing it drains the fluid out. I had a leak in the differential cover gasket anyway, so I had to do it. Watch out for the constant dripping from the case, try to keep the mating surfaces clean when you put the pan and cover back on, it'll help it seal better. If using RTV, use a 1/8" bead of RTV on the pan and cover, don't overdo it, ring the bolt holes, go slowly.
Watch out for the differential cover not being aligned with the case holes, just align the cover carefully and you'll be OK. Torque the pan and cover immediately upon putting it in, to keep the dripping fluid from messing up the seal (especially on the differential cover). Above all else, keep the insides of the transmission clean, no lint.
Put in the recommended quantity of fluid (4 qts US for the 1985 A470), and test it out! You'll be rewarded with a job as good as your capabilities allow, for much less money, and with high-quality parts and fluid. You'll also get a good look inside the tranny, to see what's up in there (any particles of old friction material in there, for example).