Help on Subaru AWD failing to engage

[Donald Hazle]

The All Wheel Drive on my 1997 Subaru Legacy Sedan is failing to fully
engage. Only one front wheel would spin when I tested on a hill in wet
grass. When I jacked both wheels on one side off the ground, the rear
would slowly turn, but I could stop it with my hands. The front wheel
turned with full force. My Subrau dealer said that there has to be
something that is not engaging. He said that there is a solenoid that
might have failed. It is also possible that a wire could have come
off somewhere. From reading other post, I assume that AWD is running
in the 90% front and 10% rear mode.

Does anyone have any suggestions as to where to look before I have to
take to into the shop. The location of the solenoid might also help.

Thanks Don Hazle

 

[Jeff]

On 6 Oct 2003 05:16:23 -0700, (e-mail address removed) (Donald Hazle) wrote:

The AWD (and other 4WD) system transfers torque between the front and
rear wheels (not from left to right). Transfer of torque from the
side to side depends on if there is a limited slip differential,
typically only installed in the rear.

If one front wheel looses traction it is the one which will spin while
no torque will be applied to the wheel still on the ground. If one
rear wheel looses traction, the limited-slip differential (if
installed), will transfer torque to the rear wheel with traction.

Even with All Wheel Drive you will get stuck if only one front wheel
has traction and the other three are on ice.

I got stuck in a 1970 Blazer where one front wheel and one rear wheel
were spinning in mud (no limited-slip differential in rear) and the
wheels on the other side of the truck were on dry pavement - even with
the transfer case in 4LO locking front and rear drive shafts.

Did you get stuck in the grass or did the rear wheels push?

I hope you didn't do anything which would risk bodily injury like
jacking up one side with the car running and in gear?

My guess is unless you got stuck, the AWD is working fine and what you
observed is typical of may AWD/4WD vehicles.

I would do more research as it sounds like the dealer does not know
how the system works. Try a Service Tech and not a salesman. If in
doubt I am sure they would be willing to have you part with some money
for a diagnostic check.


Jeff
2003 OBW
1996 Explorer
1970 Chevy Blazer (RIP)

 

[Ken Gilbert]

The All Wheel Drive on my 1997 Subaru Legacy Sedan is failing to fully
engage. Only one front wheel would spin when I tested on a hill in wet
grass. When I jacked both wheels on one side off the ground, the rear
would slowly turn, but I could stop it with my hands. The front wheel
turned with full force. My Subrau dealer said that there has to be
something that is not engaging. He said that there is a solenoid that
might have failed. It is also possible that a wire could have come
off somewhere. From reading other post, I assume that AWD is running
in the 90% front and 10% rear mode.

Does anyone have any suggestions as to where to look before I have to
take to into the shop. The location of the solenoid might also help.

Thanks Don Hazle

is it an automatic or a manual transmission?

ken

 

[Rob Munach]

On 6 Oct 2003 05:16:23 -0700, (e-mail address removed) (Donald Hazle) wrote:

The AWD (and other 4WD) system transfers torque between the front and
rear wheels (not from left to right). Transfer of torque from the
side to side depends on if there is a limited slip differential,
typically only installed in the rear.

If one front wheel looses traction it is the one which will spin while
no torque will be applied to the wheel still on the ground. If one
rear wheel looses traction, the limited-slip differential (if
installed), will transfer torque to the rear wheel with traction.

Even with All Wheel Drive you will get stuck if only one front wheel
has traction and the other three are on ice.

I got stuck in a 1970 Blazer where one front wheel and one rear wheel
were spinning in mud (no limited-slip differential in rear) and the
wheels on the other side of the truck were on dry pavement - even with
the transfer case in 4LO locking front and rear drive shafts.

Did you get stuck in the grass or did the rear wheels push?

I hope you didn't do anything which would risk bodily injury like
jacking up one side with the car running and in gear?

My guess is unless you got stuck, the AWD is working fine and what you
observed is typical of may AWD/4WD vehicles.

I would do more research as it sounds like the dealer does not know
how the system works. Try a Service Tech and not a salesman. If in
doubt I am sure they would be willing to have you part with some money
for a diagnostic check.


Jeff
2003 OBW
1996 Explorer
1970 Chevy Blazer (RIP)

You are incorrect, Sir. If it is an automatic trans model and the AWD is
working properly AND it does not have a limited slip diff in the front
or rear, worst case, one front and one rear will spin simultaneously
(assuming the transfer clutch is functional) The situation you are
describng refers to a vehicle with an open center diff. The manual trans
models have an open center diff with a viscous limited slip device. If
the LSD is not working than worst case, one front OR one rear will spin.
It sounds like it is an automatic model with a failed transfer clutch.

 

[Donald Hazle]

is it an automatic or a manual transmission?

ken

Ken,

It is an automatic. I also fogot one detail. When I inserted a 15amp
fuse in the FWD socket (which in effect locks out the rear drive so
the car can be towed), the fuse blew after I stated the car.

Don Hazle