Mechanical Testing of the Duty Solenoid

[rruge]

I have a '96 Outback Auto Trans. with 115k. Rear wheel drive was gone at about 85k.

 

I have opened the Extension housing and found that the clutch pack is worn through to the metal. I believe this is only a symptom and not the cause. The duty solenoid is electrically sound; i.e. not open or shorted.

 

When I blow through the hole on the solenoid, the valve is open. I apply the 12VDC to the solenoid and, yep, still open. Should the solenoid close the port opening with the 12VDC applied? Seems obvious, but I wanted to run this by the Board before I order the part. Also, shouldn't I hear a clicking noise in the solenoid when applying the 12VDC?

 

Thanks,

 

Richard

[blitz]

I believe the when the solenoid is activated, it allows hydraulic pressure to dis-engage the clutch. Therefore solenoid failure is generally characterized by a constant clutch engagement (binding in turns). I hope I don't have it backwards ...someone please correct me if I'm wrong.

 

Agreeing with you, I'd think the solenoid WOULD give some small mechanical noise or clunk as it were activated. I've never studied the wiring diagram on the solenoid, but it's possible that it may be supplied with a hot on it's one side when the ignition is on, and then be activated with a switched ground on it's other end. Be sure that your energizing it correctly.

[Gnuman]

Either way, the valve is open both when hot and when not. this would indicate that there is no action coming from the solenoid. there is also no sound (from the description), indicating that there is no action coming from the solenoid. if it is a "hot on ignition on" system, then applying hot should close the valve to disengage the clutch. Remember, there is no speed difference in the wheels to tell the TCU to engage the solenoid. . .

 

I would order the part.

[rruge]

A'ight,

 

 

I will order the solenoid. But I am still curious. I assume the DS acts as a valve and should be closed at some point. So blowing into the port is a reasonable way of testing this functionality. Is this right?

 

Thanks again,

 

Richard

[blitz]

Yeah, it should change states when power is applied. What's confusing me is that I was under the impression that it' a N.C. device, but your saying that it's open both ways.

 

You're gonna have to replace the clutch pack as well. I wonder if it's worn out as a result of the solenoid failing (clutch binding)? That would fit.

 

I guess I gotta break down and buy the overpriced 4EAT manual so I know what I'm talking about, I'm gonna need it eventually anyway.