Tribeca with shuddering automatic transmission

[Don Dunlap]

I have a new Tribeca with a little over 6000 miles. The problem is the
transmission shudders when shifting from second to third gear at times. It
is acting as if it can't quite make the shift and moves back and forth until
it finally finds it.

My guess at first was the software that creates the shift. I took it to the
Subaru dealer for the 6000 mile oil change and they were able to recreate
the shudder. They erased and reloaded the memory in ECU and performed some
other tests like line pressure, etc.

The problem still exists and I called the Service Manager to advise him. He
is going to check with Subaru to see if there are any other reports of the
problem.

Has anyone else encountered this problem in a Subaru transmission? What is
happening is a little hard to describe, but as I said, it seems as if the
transmission can't find third gear and is shifting back and forth rapidly
trying to shift. I thought that maybe a valve is not opening or closing or
a spring is not functioning properly, but I haven't worked on an automatic
transmission for about 45 years and I believe that they have changed a
little in that time.

Don Dunlap

 

[Ratatooie]

Try testing your tranny fluid level repeatedly under different conditions to
see if the level is right. It is my experience that "full" one day is "not
so full" the next day... so it is very easy for someone to "fill" it at a
mechanic and have it need more fluid later. There are A LOT of knooks and
crannies in there.....

Check your tire presure lately? Subaru transmissions and torque converters
do not like even small differences in circomference of the tires. Even 1
pound off between left and right rear tires can cause shuddering under
different conditions.

If you give it a little more or less gas when it shudders, what happens
then? What RPM is the engine when it shudders?

 

[Don Dunlap]

Try testing your tranny fluid level repeatedly under different conditions
to see if the level is right. It is my experience that "full" one day is
"not so full" the next day... so it is very easy for someone to "fill" it
at a mechanic and have it need more fluid later. There are A LOT of
knooks and crannies in there.....

The car is so new that I have not even thought to check the transmission
level. I 'assume' that the service dept. at the dealer checked it when I
brought it in. I'll check it now though.

Check your tire presure lately? Subaru transmissions and torque
converters do not like even small differences in circomference of the
tires. Even 1 pound off between left and right rear tires can cause
shuddering under different conditions.

I check the tire pressure every week. No problems there.

If you give it a little more or less gas when it shudders, what happens
then? What RPM is the engine when it shudders?

The shudder doesn't occur at any set RPM. If I am accelerating heavily, the
RPM is naturally high and under normal driving conditions, the RPM varies.
The shudder takes place regardless of RPM. I have tried giving it more gas
at the time of the shudder and it makes it worse. Giving it less, it drops
back to second.

It is a mystery!!

Don

 

[tony1870]

The car is so new that I have not even thought to check the transmission
level. I 'assume' that the service dept. at the dealer checked it when I
brought it in. I'll check it now though.


I check the tire pressure every week. No problems there.


The shudder doesn't occur at any set RPM. If I am accelerating heavily, the
RPM is naturally high and under normal driving conditions, the RPM varies.
The shudder takes place regardless of RPM. I have tried giving it more gas
at the time of the shudder and it makes it worse. Giving it less, it drops
back to second.

It is a mystery!!

Don

Hi, I was reading your question, I have the same problem in my tribeca.
do you find any answer to this problem?
thank you