My friend is driving a Legacy 2.5 My05 AT and having problems with the transmition (automatic). When he is driving straigt is ok, but when taking a turn or parking the back wheels are braking/sliping on the ground. He think its something with the electronic because the clutch that is in the back of the gearbox for the back wheels is always at 95% (showing on the diagnostic) but what taking a turn it must be lower than 95%. He changed some he said C valve for the back wheels clutch but same thing. Is it possible an other sensor or what?
Some suggestions???
Thanks

 

Sorry pushed twice the sent button but dont know how to delete one one the posts...sorry

 

Does the POWER light flash when the ignition is turned on? If there is a fault with the duty C solenoid it will flash 16 times. He might have a FWD light instead of POWER.
Changing the tranny fluid can help, might have to do it a couple of times.

The system uses a clutch pack which is hydraulicy squeezed. The amount of pressure is controlled by the duty c solenoid. Look under the bonnet and either in the fuse box or by the offside front wing, near the suspension tower there should be a empty fuse slot marked FWD. If you put a fuse in there it will power the solenoid 100% and no power is transmitted to the rear. It's not meant to be driven like this though as it can burn the solenoid out.

My WRX auto had the same fault. the rear wheels skip in tight turns as they are trying to turn at a different rate to the fronts. Oil change made it better but not 100%. WRX's don't have a FWD fuse either. I had to strip the clutch pack out , a PITA job. Zorst off, rear drive shaft off, Bell housing on the end of the transmission off, strip the internals and check for wear or damage.
At this point fit a new duty C as its accessable at this point and you won't want to be going back in later.
Put it all back together. WRX's are different in design to Legacy's so it will be worth doing a search for Torque Bind.
Another fault could be the clutch hub in the bell housing can get notched by the plates so they end up getting stuck in the notches. If so they can be filed smooth again.

 

Hi,
no power light falshing but the solenoid changed and oil too, but nothing better
Will tell him to look for the clutch hub.