tranny fluid change

Hi, i have a 94 plymouth voyager 3.0L with a 3 speed tranny, I recently
change the tranny fluid in the pan and the filter but i was to change the
complete tranny. Which line is the return line from the tranny to the
tranny cooler,there are 2 lines from the transmision which line is the
return line and how do i do complete tranny fluid change.

 

Why bother? The few pints left in the system after you drop the pan will mix
with the new. The "Total System Flush" is a scam to take your money. Just
follow the recommended service intervals, use the right fluids, change the
filter, and you should be fine.

Patrick

 

I have to respecfully disagree. No expert on the 3sp, but in my 4sp,
when I change the fluid, dropping the pan is only about half of the
fluid, I can get about 4.5 quarts. When I disconnect the return line, I
can watch and pour another 4 quarts in before the fluid turns red.
Flushing the entire system is almost a must with the 4speed, as they are
too sensetive to dirt and contaminents anyhow. I hear the 3sp is a
little more robust, but I will still reccommend the flush.
As to how to do it, if your unsure, just take the line at the bottom of
the tranny cooler, taking the line off at the cooler, either fluids
going to come out of the hose in your hand, or out of the nipple of the
cooler, then you'll know which way the system's pumping...

 

Disconnecting the return line won't get you any more fluid out than you
would get if you just let it drain overnight with the pan off. Once
that's done, there will still be about 3-4 pints in the convertor (below
the hub) that are impossible to drain, but that's harmless. Just change
the fluid every 50k miles or so and the little bit of old fluid left in
the convertor won't be a problem.

 

The idea would be to disconnect the return line and run the engine so
that the transmission pump pumps the fluid thru the system - (mostly)
fresh fluid in, (mostly) fresh fluid out, including the torque
converter. Granted, even doing that, it is a dilution process (i.e.,
you'll never get 100%), but it's much more of a fluid change than just
dropping the pan.

Steve - is your comment specific to that transmission, or is it
generally true. I ask because I know that with my four speed ATX (LH),
just dropping the pan will result in slightly less than 1/2 of the old
fluid being replaced, whereas if I let the pump pump out as I replace
with makeup fluid, I can probably get better than 95% replacement using
12 to 16 qts. (approx. 10 qt. capacity - again, always less than 100%
because of mixing/dilution).

Bill Putney
(to reply by e-mail, replace the last letter of the alphabet in my
address with "x")

 

My experience with all Chrysler trannies without torque convertor drain
plugs (727 and 904 from '78 on, 42LE, and A-518) is that you get about
half the fluid when you drop the pan, but if you pull the filter and let
the tranny sit open overnight with a big catch pan under it, air will
start to work past the seals and into the convertor and it will drain
fairly thoroughly back through the transmission plumbing without
disconnecting anything. It just takes a long time for the "suction to
break" so to speak. Subtracting what I've collected in the catch pan on
the 93 Vision from what the book says tells me that about 2 quarts
remain in the convertor and cooler (and soaked into the clutches, which
you'll never get out).

 

I agree with that. Go to this site and check out what oil to use:
http://www.allpar.com/fix/trans.html

Never use Mercon or Dexron! Use ATF+3 OR ATF+4. Go to the site.

Hank

 

'85 B350 with OD 727...

As a buddy of mine pointed out -

Have you ever looked at a Chilton's, and noticed that the published tranny
fluid capacity is like 18qts, but after draining, another 4-5qts fills it up
again? The torque converter has most of the fluid capacity anyhow.

That said, when you've been driving around awhile, and the fluid inside the
transmission is fairly homogenous, do you really want to mess with it
anyhow? Of course not! Change the filter to remove any contaminants and
particles that it has caught. If your engine has been off for awhile, the
larger particles in the fluid will have settled into the pan. Keep up with
the maintenance schedule as published, but hey - if it's not broke, don't
fix it!

NthDegree

 

ROFL!!!!

I once remember listening to CarTalk when a guy called to complain that he
always seemed to crossthread the oil plug, and was wondering if they thought
it'd be okay if he pulled the oil filter, then ran the vehicle to pump the
rest of the oil out.

After five solid minutes of laughter, they pointed out that running the
engine without oil was probably worse than not changing it at all.
Likewise, running the engine to flush out the tranny fluid is probably not
such a great idea. After all... the front half of the tranny is always
spinning anyhow.

NthDegree

 

Bill Putney
(to reply by e-mail, replace the last letter of the alphabet in my
address with "x")

No "likewise" to it. Running an engine with no oil in it is in no way
like running a transmission with fluid still in it as you pour make-up
fluid in.

It's very much a great idea *if* you keep fluid in it while it is
running, which is what I said in my post. That's how you get the fluid
otherwise trapped in the torque converter flushed out.

Not sure what the point there is.

Bill Putney
(to reply by e-mail, replace the last letter of the alphabet in my
address with "x")

 

Allpar.com says this only applies to the four-speed automatic. The service
manual of my '79 LeBaron recommends Dexron. So I assume that I should use
Dexron, right?

Thank you.

Jorrit Steetskamp

 

===================================

The three-speed automatic can use Dexron.

The difference is that the electronically controlled transmissions
require the critically specified friction characteristics of the
Chrysler ATF fluids for the electronics to properly apply clutches and
modulate the shifts. If the wrong amount of friction is present, the
electronics sense this as an error in operation and either make the
clutches work harder to maintain shift quality, or give up and put the
transmission into "limp in mode."

 

You can use Dexron III in a '79. You could also use AFT+3 as it is
backward-compatible. But since its more expensive, you might not want to
do so. I do use ATF+3 in the '69 A-727 I just rebuilt for my '69 Coronet
R/T. I went with it for the added oxidation protection and to take just
a little bit of the edge off the shift-kit that I have in the
transmission. Beating the tar out of the U-joints and rear axle gets old
after a while, but I hate a sloppy greasy shift. The shift kit and ATF+3
combination is perfect.