AWD question

[Earthworm]

I'm just curious as to what all the causes are of a slow to react AWD could be.

I'm thinking of 4 possibilities:

1. slow fluid flow
2. worn solenoid (C)
3. worn AWD clutch
4. low fluid

Does anyone else agree with these or have any more to add?

[svx_commuter]

TCU
Speed sensors

if the hub that the clutches ride on is warn, or have sharp edges like mine did, it would cause the clutches to not slide as easy

[Mr. Pockets]

The rear wheels on my wife's Legacy are pretty slow to engage, as well. You have to get the front wheels to slip quite a bit before the rear wheels engage with a -thunk-.

I suspect in her car's case that this is due to a worn transfer clutch.

that is exactly what mine did before the clutches were replaced..you could really feel them...mine also didnt stay locked..if you got in some snow,,u could see them start to spin, then stop

[svx_commuter]

There is a pressure gauge port on the transfer case. A reading from this tells you if the clutches are worn, has pressure but no RWD or no pressure, meaning the transfer valve assy is shot.

[Earthworm]

Originally posted by svx_commuter
There is a pressure gauge port on the transfer case. A reading from this tells you if the clutches are worn, has pressure but no RWD or no pressure, meaning the transfer valve assy is shot.

So how do I check this and what are the proper readings?

[svx_commuter]

Well the first thing I did was get an extra pressure port plug. It is a straight metric thread with an o-ring under the flanged bolt head for a seal. I matched this up to a 10.00 mm x 1.0 pitch die and it worked well on a 1/8" NPT tapered thread. I used the die to take the taper off the 1/8" NPT thread on a street elbow. It is the same thread pitch just straight instead of tapered.

I bought a 250PSI guage from McMaster-Carr. This will also cover the line pressure tests.

The SM [3-2] page 121 says 7-11 psi at idle in D or R and 104 - 114 psi when the accelerator pedal is depressed.

I got to the port connection by bending the heat shield out of the way. It is on top the transfer housing drivers side.

[svx_commuter]

The part number for the pressure port bolt seal is:
31325KA080 it's called a BOLT AY-SEAL