Just what is Duty Solenoid C?
 

Ive been reading about people having binding issues, and that seems to be the fix. My car gives a little clunk when I go into reverse, and also shakes a little when turning at a slow speed. Does this sound like my car is binding? I dont know what it means... If so, how much is the new solenoid? And just how hard is it to replace? What happens if I dont replace it? Though I have driven a few SVX's, and they all seem to do the clunk thing into reverse...

-Dennis

Re: Just what is Duty Solenoid C?
 

D J,
FSM states "Duty Solenoid C (Transfer) is mounted to the transfer control valve on the side of the extension case (far rear of transmission), and its duty ratio is controlled by the signal sent by the TCU. It then controls the transfer control valve for controlling the transfer clutch hydraulic oil pressure." It appears to basically control the amount of torque transferred to the rear wheels under various traction conditions.
"When DS3 becomes inoperative it turns OFF. This causes maximum oil pressure to be applied to the transfer clutch so that power is always transmitted to the rear axles. (Direct-coupling AWD)."
If you have ever driven a 4WD vehicle on dry pavement with the rear wheels pushing as the front wheels attempt to turn left or right, they cause a good deal of "judder" and wear on the front tires as they attempt to rotate while simultaneously being pushed forward, creating an "eraser" effect. A correctly performing AWD system incorporates a viscuous coupling or clutches that allow front and rear wheels to turn at different rates, preventing this "binding".
Hope that makes some sense. As far as accessibility, this is a fairly major job to undertake replacement, as in 3 full pages of instructions and diagrams in the manual. Subaruparts.com prices Duty Sol-C out at about $80.

Glenn

Re: Just what is Duty Solenoid C?
 

I have the same "clunk" when I put mine into reverse but that's because my rear diff. bushings are shot badly. Check yours that maybe the problem.

It has been recommended in the past to replace the entire solenoid assembly if the C has quit, as it is likely the others could be on their way out soon enough. It is a fairly major job.

Re: Just what is Duty Solenoid C?
 

The "clunk" going into Reverse could also be a shot rear transmission mount.

Glenn

Re: Just what is Duty Solenoid C?
 

Put your FWD fuse in and see if your car still shudders around corners, if it does, the problem is not the duty solenoid.

The clutch packs wear grooves into the transfer drum, and then the clutches will hang up and cause shuddering/binding, the master tech at my work told me to go to an empty parking lot and do several tight circles in each direction and it will usually loosen them up.

Re: Just what is Duty Solenoid C?
 

The parking lot circles, would it be done with or without the FWD fuse in?

Paulo

Re: Just what is Duty Solenoid C?
 

It needs to be in 4WD mode Paulo. :)

Have you checked out if your German model has the same trans as the USA type? Does putting in the fuse give you 2WD?

How's it going, all right?

:)