91 subaru legacy L auto transmission problem

[dweller]

I checked in this site a year or so ago, and got some great advice on
changing my timing belt which went successfully well. Now, am having
an occuring problem with the trans. I have been searching the archived
threads, and learning a bit, but want to ask a bit more.

I have been experiencing a bit of hesitation ( i thought) over the
last month or so. Checked the plugs, trouble codes, etc. and nothing
to be concerned with, but along the way realized that the hesitation
occured during open road driving. Just a slight drag for a few
seconds, and then fine again. Then i noticed the tach elevating during
the 'drag' and have had the trans slip into a lower gear several
times. Noticing the tach response led me to understand that it was
slipping into a lower gear (D to 3) and once as i was stopping at a
light, it shifted from whatever gear it was in, to the next lower
quickly. I didn't manually shift it back up, it just shifted back on
its own.

Now, i've read dozens of threads on the 91 trans: the filters-
internal and external- and changing them and still don't know what is
causing the problems. Is it a dirty filter? One filter is supposed to
be lifetime, the other is recommended replacement, but i'm not sure
which needs what. The internal i've read here can be cleaned, but the
auto parts stores here (NC,US) only sell the internal. The external
ones (added on, for the trans cooler) should be replaced ? but no
parts store knows what i'm talking about with it, and my Haynes manual
shows the lines for the cooler into the radiator, but not the filter
that is in that line. Again, i understand the filter was added due to
recall, but does it need replacing?

And, again, what is causing the problem? I've changed the trans fluid
but it didn't change the slipping down. I understand that the simple
draining/adding 4 qts is not changing all of the fluid, and perhaps
the flushing/replacement of complete fluid is needed and will seek
that next week. I'm just wondering if someone has found this to be the
actual remedy, or does this problem actually exist further than a
fluid change remedies? I've read not to have the band adjusted, and
don't want to just turn this over to a trans mechanic for work that's
not needed.

At this point in time i have my time and resources (read $$) tied up
in another vehicle that i get more than enough crap (read smartass
answers from another group dealing with that engine) and as this is my
daily driver and the other is a recreational vehicle only (okay, it's
a vw camper) i'd appreciate any serious reply. Just want to know if
the filter/filters/complete fluid change remedy the problem, or does
something more serious underlie it all .

thanks in advance for your help.
dp

 

[strchild]

Maybe what you are experiencing with your RPMs upping and power dropping is
torque converter slippage? I can't really say as I've never experienced it
firsthand. Might be worth calling a transmission shop to pick their brain
about the symptoms of torque converter failure.

Has the car ever been used to tow, or ever been towed with any / all wheels
on the ground? Does the occurrence of the symptoms increase during curves
or occur about the same with straight-aways?

To test for torque bind between the front and back wheels you can insert a
fuse into the FWD fuse holder located in the engine compartment near one of
the strut mounts. That will put the transmission into front wheel drive and
you should be able to turn with no torque bind-up, if that's even related to
the problem. Might take it back on the highway and see if the symptoms have
diminished.

If you search the Subaru newsgroup here, somewhere should be the procedure
to coax any trouble codes from your transmission. They will blink out on
the power light on the dash, just like the engine uses the check engine
light to blink it's codes. Does your power light on the dashboard flash
when you turn the key to the on position before starting the car, or remain
on steadily as the other lamps do during the lamp test?

~Brian

 

[johninKY]

No 91 Legacy has the external/inline ATF filter. Only found on much newer
models.
Just curious but why are you reluctant to tighten the band?

 

[dweller]

No 91 Legacy has the external/inline ATF filter. Only found on much newer
models.
Just curious but why are you reluctant to tighten the band?

Mine does, just as described by the prev messages here on the subject.
My Haynes manual shows the lines for it, but not the filter. On my 91
in those lines is mounted a filter that has a snapband holding it to
the engine wall.

From what i've read, they were added on recall.

From reading the many previous threads, it was the advice not to

adjust the band. I'm reluctant to jump on this as the remedy, since i
don't really know what is causing it.

dp

 

[dweller]

Maybe what you are experiencing with your RPMs upping and power dropping is
torque converter slippage? I can't really say as I've never experienced it
firsthand. Might be worth calling a transmission shop to pick their brain
about the symptoms of torque converter failure.

Has the car ever been used to tow, or ever been towed with any / all wheels
on the ground? Does the occurrence of the symptoms increase during curves
or occur about the same with straight-aways?

To test for torque bind between the front and back wheels you can insert a
fuse into the FWD fuse holder located in the engine compartment near one of
the strut mounts. That will put the transmission into front wheel drive and
you should be able to turn with no torque bind-up, if that's even related to
the problem. Might take it back on the highway and see if the symptoms have
diminished.

If you search the Subaru newsgroup here, somewhere should be the procedure
to coax any trouble codes from your transmission. They will blink out on
the power light on the dash, just like the engine uses the check engine
light to blink it's codes. Does your power light on the dashboard flash
when you turn the key to the on position before starting the car, or remain
on steadily as the other lamps do during the lamp test?

~Brian

The salesguy where i bought my fluid mentioned that, and sold me an
additive for torque conv slippage, he called it 'torque shudder'. I
haven't added it yet. A mechanic (not trans mech) was pointing out the
inline filter to me, and rec'd changing it.
This is a 2w drive vehicle. No rear drive. Haven't noticed it more on
curves, or in turning. Mostly just as it upshifting. For example: as
i'm starting off from stop, shifts from 1st-2nd, 2nd-3rd fine. Near
when it should be 3rd to D it will shift, then drop back mometarily
to 3rd, then back to D. And then after as i'm driving 40-50 mph, i
will feel the shift down, the upwards tach, and then it shifts back to
D. This happens for a second or two then doesn't happen again unless
i'm slowing down/building up speed again. Only once as i was
decelerating at a stop light, i felt it slow quickly and saw the tach
zoom up then return to a normal gear/rpm. I was slowing on a downhill
at a light that changed and was stopping quickly anyway.
Mine is OBD I and the only code for the trans is for the inhibitor
switch malfunctioning, and of course my manual doesn't mention that
switch at all. But no codes are on, no light etc.
I've never used this car to tow, but prev owner might have, don't
know.
thanks
dp

 

[johninKY]

Can't have "torque bind" in a FWD transmission.

I wonder if you are confusing the fuel filter with an inline ATF filter?

 

[dweller]

Can't have "torque bind" in a FWD transmission.

I wonder if you are confusing the fuel filter with an inline ATF filter?

Would the fuel filter line run in/out the side of the radiator? This
as far as i can tell from diagrams in my Haynes is the trans cooler
lines, and the filter is in that line. The mech mentioned above called
it the trans cooler filter. I realize there is one also internal to
the trans fluid pan. It's the only one i can find a replacement for at
this point. Subaru may offer the other external one. Just trying to
determine which is lifetime, which is replaceable, and if it is
causing the above slipping btwn gears.

thanks for input.
dp

 

[Jr]

Have a 91 Legacy L+ FWD and there was a recall soon after I bought the car
in 91 to put a filter in the transmission line due to the possibility of
sand being left in the transmission from the casting process.

 

[dweller]

Have a 91 Legacy L+ FWD and there was a recall soon after I bought the car
in 91 to put a filter in the transmission line due to the possibility of
sand being left in the transmission from the casting process.

Did you ever have that filter changed? I'm unable to find a
replacement for it so far, will have to check w/SOA tomorrow.
dp

 

[Jr]

If I remember from the recall they said it would not be necessary to ever
have the filter changed, it is a pretty good size filter.

 

[dweller]

I checked in this site a year or so ago, and got some great advice on
changing my timing belt which went successfully well. Now, am having
an occuring problem with the trans. I have been searching the archived
threads, and learning a bit, but want to ask a bit more.

I have been experiencing a bit of hesitation ( i thought) over the
last month or so. Checked the plugs, trouble codes, etc. and nothing
to be concerned with, but along the way realized that the hesitation
occured during open road driving. Just a slight drag for a few
seconds, and then fine again. Then i noticed the tach elevating during
the 'drag' and have had the trans slip into a lower gear several
times. Noticing the tach response led me to understand that it was
slipping into a lower gear (D to 3) and once as i was stopping at a
light, it shifted from whatever gear it was in, to the next lower
quickly. I didn't manually shift it back up, it just shifted back on
its own.

Now, i've read dozens of threads on the 91 trans: the filters-
internal and external- and changing them and still don't know what is
causing the problems. Is it a dirty filter? One filter is supposed to
be lifetime, the other is recommended replacement, but i'm not sure
which needs what. The internal i've read here can be cleaned, but the
auto parts stores here (NC,US) only sell the internal. The external
ones (added on, for the trans cooler) should be replaced ? but no
parts store knows what i'm talking about with it, and my Haynes manual
shows the lines for the cooler into the radiator, but not the filter
that is in that line. Again, i understand the filter was added due to
recall, but does it need replacing?

And, again, what is causing the problem? I've changed the trans fluid
but it didn't change the slipping down. I understand that the simple
draining/adding 4 qts is not changing all of the fluid, and perhaps
the flushing/replacement of complete fluid is needed and will seek
that next week. I'm just wondering if someone has found this to be the
actual remedy, or does this problem actually exist further than a
fluid change remedies? I've read not to have the band adjusted, and
don't want to just turn this over to a trans mechanic for work that's
not needed.

At this point in time i have my time and resources (read $$) tied up
in another vehicle that i get more than enough crap (read smartass
answers from another group dealing with that engine) and as this is my
daily driver and the other is a recreational vehicle only (okay, it's
a vw camper) i'd appreciate any serious reply. Just want to know if
the filter/filters/complete fluid change remedy the problem, or does
something more serious underlie it all .

thanks in advance for your help.
dp

Update: okay, i pullled the external filter loose from the snap band
it was held by, and cleaned it off. The brand name on it looks like
Kydaon ... could be Kydron ? It's stamped into the side of the
housing (raised letters in script of some sort, Upper case K, lower
case on the other letters. The same K alone is in raised letter on
the housing, so it may be a brand trademark.
Number in paint/top on the bottom 6M19

nothing showing up in a web search with the brand or number. It is
about the same size as an oil filter, but with 2 ports that the trans
fluid lines run, one in, one out of the filter that run in/out of the
radiator.

i guess i will have to contact SOA tomorrow.

anyone else have this trans cooler filter attached on their early
Legacy? I did locate a trans cooler filter for Subs online:
#38325AA032 but it was for 99 and above years.

dp