Problem with Auto Tranny AWD clutch pack or control unit ???

[subaruVWnut]

Car is a 96 OBW with DOHC 2.5L and auto tranny.

 

Inital symptom was torque bind on tight turns.

 

Swapped Transmission Control Unit with another..didn't fix the

problem. Swapped tranny fluid....also not a fix.

 

My assistant is a knowledgeable all around Subaru wrench....but he's a stick shift guy and doesn't know a lot about the inner workings of the 4EAT tranny, ..........so we both read up on torque bind...seems problem is usually binding of the clutch plates in the clutch pack or problem with the

Duty C solenoid in the tail housing that controls the proportioning valve

 

...so we removed the rear tail housing of the tranny. The transfer clutch plates all seem to be OK and moving easily against each other. Removed the Duty C solenoid that controls the proportioning valve ...checked and

it's operating. It seems OK. Replaced the gasket in the proportioning valve with a new one. Reassembled everything and re-installed the tranny.

 

On test drive there is a NEW AND WORSE problem.....a

pronounced clicking sound on each revolution coming from the rear of the tranny/tailhousing area....and sometimes sounds like marbles in there.....BAD SOUNDS.

 

I assumed we must have put something backtogether wrong.

 

Frustrated......and feeling over our collective heads with the 4EAT in general, I obtained another complete tranny from a wrecked 98 OBW and have it swapped iin.....result....no difference .exact same clicking and "marbles " sound as the previous tranny had after it was re-assembled.....

 

Hard to believe that two different trannys would have the exact same symptoms....

 

CLUES:

 

All sounds go away and it drives normally with the fuse in

place in the "FWD" receptacle in front...so it seems the problem is somewhere in the transfer clutch pack and/or it's electricl components.

 

My friend also notes that there seems to be more than the usual amount of play in the rear diff..

 

I'd appreciate help here......this has been a very frustating problem and a lot of time and labor involved so far...

 

I'm wondering if its possible ...after re-installing the tail housing (in the first case) and the tranny in the second case...and then putting tranny fluid back in...that somehow the fluid is not getting into the clutch pack so that the plates are getting tranny fluid. Possibly no power to the Duty C ????

 

Just not sure if this is a mechanical problem....or an electrical one.....causing the Duty C unit to be not activating.

 

..or possibly some other part I'm not aware of. Doesn't seem like two different trannys would have bad Duty C's.

 

 

Warren C

[1 Lucky Texan]

Car is a 96 OBW with DOHC 2.5L and auto tranny.

 

Inital symptom was torque bind on tight turns.

 

Swapped Transmission Control Unit with another..didn't fix the

problem. Swapped tranny fluid....also not a fix.

 

My assistant is a knowledgeable all around Subaru wrench....but he's a stick shift guy and doesn't know a lot about the inner workings of the 4EAT tranny, ..........so we both read up on torque bind...seems problem is usually binding of the clutch plates in the clutch pack or problem with the

Duty C solenoid in the tail housing that controls the proportioning valve

 

...so we removed the rear tail housing of the tranny. The transfer clutch plates all seem to be OK and moving easily against each other. Removed the Duty C solenoid that controls the proportioning valve ...checked and

it's operating. It seems OK. Replaced the gasket in the proportioning valve with a new one. Reassembled everything and re-installed the tranny.

 

On test drive there is a NEW AND WORSE problem.....a

pronounced clicking sound on each revolution coming from the rear of the tranny/tailhousing area....and sometimes sounds like marbles in there.....BAD SOUNDS.

 

I assumed we must have put something backtogether wrong.

 

Frustrated......and feeling over our collective heads with the 4EAT in general, I obtained another complete tranny from a wrecked 98 OBW and have it swapped iin.....result....no difference .exact same clicking and "marbles " sound as the previous tranny had after it was re-assembled.....

 

Hard to believe that two different trannys would have the exact same symptoms....

 

CLUES:

 

All sounds go away and it drives normally with the fuse in

place in the "FWD" receptacle in front...so it seems the problem is somewhere in the transfer clutch pack and/or it's electricl components.

 

My friend also notes that there seems to be more than the usual amount of play in the rear diff..

 

I'd appreciate help here......this has been a very frustating problem and a lot of time and labor involved so far...

 

I'm wondering if its possible ...after re-installing the tail housing (in the first case) and the tranny in the second case...and then putting tranny fluid back in...that somehow the fluid is not getting into the clutch pack so that the plates are getting tranny fluid. Possibly no power to the Duty C ????

 

Just not sure if this is a mechanical problem....or an electrical one.....causing the Duty C unit to be not activating.

 

..or possibly some other part I'm not aware of. Doesn't seem like two different trannys would have bad Duty C's.

 

 

Warren C

 

If the problem goes away with the fuse in FWD then the dutyCsolenoid is functioning (doesn't mean the TCU or the valve's seat is good though I guess???). Might be worthwhile to get an o'scope on the signal to the solenoid - without the fuse in place of course, to see what the TCU is sending it. maybe a wheel sensor is giving the TCU some bad info? I dunno

 

try searching here for torque bind or duty solenoid threads. Concentrate on any with 5 star ratings of more recent dates.