A-904 TC fill quandry

On a A-904, like the 727, the torque converter doesn't fill in park,
only in neutral, which is a really good safety feature, if you stop
and think about it. I notice after sitting a couple of days, if the
car is started in park and moved directly to either rev. or for.,
there's an initial "bump," not too hard, but firm. When it is first
shifted to neutral to fill the converter, initial engagement is
smooth. Once the car's been warmed up and driven, further engagements
are perfect. To proove that this may be part of the bumpy engagement
when cold, I put the cooler supply line into a pan and listened as it
was filled....sounds like a small amount of air is burping out of the
converter when first shifted from park to neutral.

Is this common, or is there a leaky converter check valve in play
here? Any "easy" fix for same, or just the nature of the Torqueflite?

 

The condition is perfectly normal and is often called "morning sickness".
There is no converter check valve so converter leakdown will occur when the
car isn't running.

There are kits made by TransGo and Sonnax that allow the converter to refill
in Park but the cheapest fix is to get in the habit of making the initial
startup in Neutral instead of Park.

 

Actually, the layout having no drive from the converter's turbine in
park is a good, well thought out engineering idea, so I'll keep it.
Now I have to train the wife for a week on how to do that! It took a
month to get her to release the parking brake AFTER applying the
service brake to prevent parking pawl binding from being "loaded,"
which I hear is also common on RWD Chryslers and anything else, from
my experience. At least they don't wind up popping into reverse, like
the pre-1969 Fords did!

Thanks for the reply, John.

Now if I could only figure a good retrofit to knock off that TCC while
climbing a grade in direct drive, life would be serendipitous

 

look out fellas- next DeserTBob will be telling you to teardown the
entire top end of the motor, and pull the oil pan and pump, when the
problem is a stuck thermostat

 

You don't understand what John's talking about. The change that the
TransGo kit makes to the valve body that allows the TC to fill in park
has nothing to do with "drive from the turbine." It has to do with
whether or not fluid from the pump (which is NOT driven by the turbine)
gets dumped straight back to the pan (factory configuration in "park")
or gets circulated through the transmission cooling system as it does in
neutral. The idea of *not* circulating the fluid when in park is the
only stupid thing the factory did with the Torqueflite transmissions. It
has no advantage, and several disadvantages (slow or no filling of the
TC in park, no heat rejection in park, less lubrication of the
disengaged clutch packs in park, etc.).

 

Hi...

Anyone know if that also applies to my 94 lhs 3.5?

Better to start and idle in neutral than in park?

Thanks, and take care.

Ken

 

OK, thanks for that. I'll just idle in neutral until it's time to
pull the valve body, and then add a kit. I checked this out on
TransGo's site, and there was evidently a common shop "cure" of
drilling a small hole in the pressure reg. to allow the TC to fill in
park (and thus give cooling and lubrication,) but that makes TC
drainback a bigger problem, so I'll just use John's neutral cure for
now.

 

I'm pretty sure it does NOT. The 41TE/42LE transmissions are pretty much
unrelated to the older ones. Hydraulically, they have a good number of
simplifications to the basic system. Some good- like full circulation in
"park." Some really BAD, like no variable line pressure regulator- they
run full pressure 100% of the time which is one reason they can run so
hot and are so hard on fluid. The giveaway is that the instructions tell
you to check the fluid in PARK on those, which implies that full
circulation occurs in park.

 

Well said. The open leak at the manual valve in the Park position is a
holdover from the old pushbutton shifter days when there was no Park
position in the quadrant and the engine had to be started in Neutral.
After 40+ years it's hard to figure why Ma Mopar has chosen to ignore this
condition when the aftermarket has recognized it for years and done
something about it.

 

Hi Steve...

Thanks, sure appreciate the info...

Take care.

Ken

 

I was wanting to ask a question about the 42LE, but didn't want to take
the thread too far astray - but, thanks to Ken, it's now one step closer
to what I wanted to ask (so Ken and I will share the blame for thread
drift here):
As a DIY'er, I prefer to replace the ATF+4 by disconnecting the cooler
return line and letting the tranny pump pump fluid out (while adding
makeup fluid at the filler) - the idea being that, assuming enough fluid
(12 to 14 qts. with approx. 10 qt. capacity) is pumped out/poured in,
essentially all fluid will be replaced, including what would otherwise
be trapped in the torque converter. Is fluid in fact actively pumped
thru the torque converter with it in park, or am I fooling myself about
that? (Also, this would be done following dropping the pan and
replacing the filter - just thought I'd save someone the trouble of
saying I needed to do that too.)

Someone in the past - possibly you, Steve, has posted that without the
wheels turning (i.e., jacking up the front end), old fluid would sit on
the TC during the intended fluid exchange.

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

 

Sorta. What you've done is mix new fluid with old, unless you're
evacuating a lot of the old fluid first before adding fresh. What I
do is get the TC and trans in general warm by power braking it for a
little while, shut down, put the funnel in the filler pipe, remove the
outlet hose from the cooler and put a hose down into a drain pan,
restart in neutral, pump down until the pump just starts sucking air,
add two quarts simultaneously, wait for that to pump down, add two
more, pump that down, then shut down and drop the pan to change the
filter and adjust the bands. (This if that A-904). Due to the new
fluid being cooler than the old in the converter, it will natually be
slighly more viscous (especially ATF+3) due to its temperature and
tend to gravitate to the outside to the TC shell, forcing the warmer,
lighter old fluid out through the annular port. Still have to drop
the pan for the filter and bands, then blow out the lines and cooler,
replace filter and gasket, done.

From what the experts have said in here about no check valve in the TC
circuit of a Torqueflite, I would imagine that shooting air back
through the cooler line toward the TC might get a little more fluid
out of the TC, but not much.

Steve might have his own views on this. One thing I think we'd both
agree upon...wouldn't it be NICE to have drain plugs back on TC shells
again?? The got rid of them for what...to save a buck a vehicle?

 

BEWARE-this OP is a troll-and a pathetic one at that !

 

Yes, considering you're almost gone, you are "pathetic."

Charles M. Nudo, Jr., of Drums PA, is almost at the bitter end of his
long trolling career. He has had no less than fourteen Google Groups
accounts canceled for this activity, six within the last 72 hours.

Please do everyone a favor, and complain about his 'nymshifting and
trollshifting activities to:



Be sure to copy the entire troll message, including headers, in your
complaint. Google Groups has come out of "beta mode" and is now
getting serious about "cleaning up" its trollers and spammers.

Tks.

 

I recognize that - that's why in several past posts on the subject, I
have *always* identified it as a *dilution* process, realizing that it
will never be 100% new fluid. I figure doing this with 12 to 14 qts. in
a 10 qt. system will conservatively result in 95+% changeout of fluid
(beats simple pan drop for less than 50% fluid changeout).

Yep - I drop the pan and change the filter first.

That's what I do except I don't do any power braking, and no bands to
adjust in the 42LE. And I add fluid before it sucks air. I put qt.
increment marks on the translucent waste bucket and add fluid at roughly
the same rate is it gets pumped out.

So does that process pump fluid thru the TC or not? Or do the wheels
have to be spinning to accomplish that?

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

 

TC action is independent of output shaft movement, and yes, on that
one, according to Steve and others, the TC is getting new fluid while
in park. Not so the RWD Torqueflites, which must be in neutral.

 

IGNORE THIS TROLL named "DeserTBob"- he was a Bell Telephone "phone
guy" who got axed, and is currently unemployed. He has ZERO KNOWLEDGE
of cars.

To see who you are getting here, check his "myspace" page below

http://profile.myspace.com/index.cfm?fuseaction=user.viewprofile&friendid=30321125

notice, no mention of cars

 

Please forward this complete post, including headers, to:



Include the words "trollshifting" and "'nymshifting" in your
complaint.

I will not respond to this now obviously psychotic troll again, but I
do appeal to you do file complaints of newsgroup disruption with
Google Groups, his only Usenet access. Google Groups has left "beta"
mode and now is taking troll and spam complaints quite seriously. This
troll has had no fewer than 20 Google accounts canceled for these
activities, seven in the last 72 hours.

Tks.

 

Banned accounts of net stalker Charlie Nudo:

thenudofamily-at-epix.net
quad8-at-epix.net
bb69-at-epix.net
analog-at-epix.net
hsf18-at-epix.net
dynobot-at-hotmail.com
winchester1886-at-hotmail.com
coltblackpowder-at-hotmail.com
powerchordg-at-yahoo.com
streambredbrownie-at-yahoo.com
nativebrookie-at-yahoo.com
trippin28track-at-yahoo.com
trippingtoo8track-at-yahoo.com

7 of them in the last 72 hous for stalking Bob. Will he ever learn?