No reverse gear on 2000 Saturn SL2 A/T

I have suddenly lost reverse gear on my 2000 Saturn SL-2 with 108,000 miles
of mostly (95%) highway miles. I have done the automatic transmission
fluid and filter changes every 30,000 miles. There are no tranny fluid
leaks, or fluid loss. The A/T has worked flawlessly up until four days
ago.

On the first day, the A/T started to hesitate to shift into reverse (from
park). The engine would rev up to 1500rpm for two seconds, settle back
down to normal idle speed, then the A/T would shift hard into reverse.
This pattern repeated whenever I shifted into reverse during the first
day, whether the engine was cold or hot.

On the second day, the reverse gear problem continued and a new twist
developed. Sometimes the first-to-second gear shift would be a hard jerk
instead of a smooth transition; usually when accelerating moderately from
a stop. The A/T would usually jerk-shift into reverse when the engine was
cold, but now refused to engage in reverse at all when the engine was hot.
The first-to-second jerk still occurs intermittently.

During the last two days, the A/T refuses to shift into reverse whether
the engine is cold or hot. The first-to-second jerk still occurs
intermittently.

On the last day, the SES lamp came on. Had the codes retrieved and got a
P0113 and P0732. P0113 is Intake Air Temperature sensor input above
maximum acceptable range. I plan to replace the sensor ($8.00) and get
the SES lamp reset. P0732 is Gear 2 Incorrect Ratio. This code was
stored in memory two times, along with the P0113.

I am not sure what to make of the P0732 code. Does it indicate that an
external solenoid/modulator part needs replacement to fix my reverse gear
problem? Or, does it indicate there is an internal (i.e. expensive)
problem in the A/T that requires the attention of an A/T mechanic? If
anyone else has had this problem, and had it diagnosed by a mechanic or
had it repaired, I would apprecate your input. Thanks for any help.

 

P0732 - GRV Gear 2 incorrect ratio Mechanical/hydraulic failure,

 

It's the latter. The 2nd gear clutch is fuct. IIRC, saturns (the only
non planetary sold out there besides Honda, BTW), use some thing off of
2nd gear to get reverse. Anyway, by now, the wrong ratio code means
you've got a clutch that got killed, probbably due to a seal leak in
either the 2nd gear clutch or the seal rings for the passeges feeding it.

Get a rebuild, make SURE they replace the converter and flush the cooler
good.

Don't expect this to be cheap, you almost certainly need a new
transmission. Sorry

 

I can't totally recall but the symptoms sound a lot like when I had to get
get my input shaft nut replaced on my 95 SW2.

 

Sounds like a valve body. YOu can buy the upper VB from Saturn from about
$200. Definitely worth a try.
Larry

 

Although I have always repaired all manual transmissions I have owned, I
did not have the time (or inclination) to play with teaching myself how to
service an automatic transmission. After four days, I parked the Saturn
and started driving a backup car I have in order to prevent further
possible damage to the Saturn.
I spent a week getting repair quotes from various transmission repair
shops. This was an experience in and of itself.

One major chain shop offered a free diagnosis service. The diagnosis
determined there was some internal problem with the transmission, but the
transmission would need to be removed and opened up to determine the exact
problem. They quoted $510 (6 hours X $85/hr) to remove, inspect, and
reinstall the transmission. Any repairs would be additional to the $510,
and could go as high as $1500. The cost would also depend on what “grade”
of warranty you wanted (1year/12000mile, 3year/36000mile, etc.).

Another major chain wanted $49.99 just to diagnose my transmission, with
that amount going toward the repair total if I had them do the repairs. I
said no thanks.

A Saturn dealership repair shop wanted $85 to diagnose the transmission,
with that amount going toward the repair total if I had the dealership do
the repairs. I said no thanks to Saturn.

I checked out two family-owned transmission repair shops in my town. One
wanted $2400 to do a rebuild, gave a 1year/12000mile warranty, and wanted
the car five workdays. The other wanted $1700 to do a rebuild, gave a
1year/unlimited-mileage warranty, and wanted the car three workdays.
Since I drive the Saturn about 25,000 miles a year, I went with the second
shop.

The work was done in two and a half days. The mechanic found the cause of
my troubles was a nut that had loosened on the back of the main shaft.
This allowed enough play to where reverse gear would eventually not mesh.
He also said the Saturn transmission uses a right-hand thread on this nut,
which is the same direction the shaft rotates. He said the Honda
transmission (the only other non-planetary) uses a left-hand thread on the
nut with a right-hand shaft rotation. It is possible that rotational
inertia of the Saturn right-handed nut causes it to loosen in certain
circumstances, such as an abrupt increase in RPM when accelerating hard.
My mechanic addressed this problem by securing the nut with Locktite when
he torqued the nut on the shaft.

After I got the Saturn back, the transmission would jerk a bit whenever
upshifting and downshifting between first and second gear during the first
twenty miles of use. Then the shifting smoothed out to normal and has been
working fine since—about two weeks now. I asked the repair shop about this
and they said the powertrain computer need to “relearn” the shifting, as
well as my driving habits.

By the way, do not expect any shop to repair an automatic transmission and
give a useful warranty. All shops I spoke with recommended rebuilding, not
repairing, an automatic that has over 100k miles on it. All shops I spoke
with would not give any warranty on a “repair-only” job since a seal,
clutch, or some other part could fail anytime after the repair.

 

Sounds like your "homework" paid off resulting in your finding a very
knowledgeable and efficient shop/mechanic. I hope the re-built transmission
lasts another 200K miles!

Bob