Re: transmission slipping

[jlandry@domain.elided (John A. Landry)]

Rob, your post just hit the Digest today...

On Mon, 5 Jan 1998 08:26:00 -0700, rhughes@domain.elided wrote:

[Big snipola]

>I refilled the ATF, and things are okay now, I _hope_.  Unfortunately, I
>haven't really had a chance to drive it much yet, so I don't know if that
>subtle slipping is still there.  If it is, I'll probably be back, but here
>are some other questions for the meantime:
>
>When I made my first emergency ATF refill, I carelessly pulled Type F off
>the shelf (I'm supposed to use Dextron (or is that Mercon) III, right?).
>There are two quarts of Type F in my tranny -- though I hope at least some
>of it is on the Autozone parking lot.  Is this a big problem?

Based on the ratio of type F you put in verses Dextron, no.

> Do I need to change all the fluid right away?

Personally I would!  But when you drain the pan, you should also drain the
torque convertor.  You have to remove the front inspection plate right
behind the engine and rotate the crankshaft until the drain plug is located
at the bottom.  Change the filter while you're at it, because it could
probably stand it too.

>Will it cause any damage?  I drove probably 40-50 miles since I put it in.

Not really... maybe will not be beneficial for the long life of the
transmission.  As I understand it, type F fluid affects the transmission
seals differently that Dextron.  It also has different hydraulic
characteristics.  I'd just get it out of there as soon as possible.

>Is low fluid the only -- or the most likely -- cause of slipping?

Absolutely.  No fluid = no hydraulic pressure to actuate and hold the
transmission bands.  You experienced the classic effect of low fluid.

>Might there be another, more serious problem?

Very doubtful.

>Might another problem have created abnormally high pressure, causing the leaks in the first place?

Again, doubtful... especially if it works fine now.  The fluid in the
cooling lines is under pretty good pressure to start with, so if the hose
was oversized and loose, it's a mechanical failure waiting to happen.

>Does my tranny (it's stock on a '75, so I'm pretty sure it's a 727) have a
>lockup torque converter?

Nope.

>Is there a way to tell if it isn't working?

Nope... hard to do when there isn't one!

>Would it's function be related to any of the above issues?

See above.

>Would pulling the speedo cable have anything to do with my problems?

Absolutely not.

>As I've thought about it more, it seems like it wouldn't.

Smart thinkin'.

>The t-case and the tranny don't share fluid, do they?

No... and you should check the transfer case *gear lubricant* once and
awhile too.  Because of seeping seals, it could also be low.

>Is there a vacuum signal hose for the tranny?

Nope.

>Where?

Nowhere.

>I'd like to check it if there is one.

Save your time.

>Can I use some type of goop on the rubber hose-to-metal pipe fitting, to
>further reduce the chance of leakage?

I'm pretty sure the factory way the transmission cooling was installed was
with hard piping all the way to the radiator.  In your case, it's apparent
that either a previous owner disconnected the original cooling lines from
the driver's side of the stock radiator and installed that aftermarket
cooling unit.  This could have been the result of wanting better
transmission cooling or maybe the radiator was replaced and didn't include
the integral cooling tubes.  Or, if the radiator is stock and lacks the
tranny cooling tubes, then maybe the transmission was added later?

It's common when the original metal transmission cooling lines have to be
cut or spring leaks, rubber hose is added as a replacement.  There's
evidence that the TF727 tranny on my Traveler was worked on at some point
in its 22 year life, and it looks like the metal lines were simply cut to
speed removal.  Short lengths of rubber hose with dual worm gear clamps
were used to bridge the gap.  One of my long term goals is to completely
replace these aging steel cooling lines with newly fabricated replacements
made by me.

>The tranny cooler is now sitting out in front of god and everybody on the
>front of the radiator, unprotected by the AC.  Suggestions on protecting
>it/making the grill look cleaner with a dark screen-type material behind
>the grille?

How about some sort of medium to fine stainless steel expanded metal?  You
could paint it flat black and place it right behind the plastic grill.  If
you choose the size of the openings carefully, it would tend to mask the
cooler behind it, yet not block the airflow substantially.

>Is the tranny cooler stock? (It's a rectangle about 10" x 5", with a
>w-shaped pipe threading through fins)

I don't believe so... I can't find anything like that in the IH parts book.
Sounds like a classic aftermarket cooler.  The original was part of the
main radiator.

>Is it sufficient?

Probably better than stock, for it doesn't share the same coolant heated by
the engine.  On the other hand, on a cold day the engine has no chance to
help warm the transmission fluid and quickly bring it up to operating
temperature.

>Suggestions on upgrading?

No need... it sounds fine.  But I'd sure take a hard look at those cooling
lines and maybe consider getting the correct size hose for the rubber
sections.

Good luck,

John
------------------------------------------------------------------------
jlandry@domain.elided             |
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