Possible AWD Failure On a Manual and Still Drive OK?

[roadsubiedog]

I took my 97 legacy in the snow for the first time yesterday and it seemed like the AWD was not working. is that possible and still shift and drive ok? ive had for about 6 months and it runs real well. it shifts fine and doesn't make any noises at all.

 

I have a 99 outback that goes like a tank in the snow so I know the difference.

[Fairtax4me]

The common failure for the manual AWD is to lock up and cause torque bind. Basically 4wd all the time. Fine for offroad, but it makes the tires skip and chirp when turning on dry pavement.

If you can confirm that the rear wheels aren't driving at all, the most likely issue is someone removed the rear half of the driveshaft, likely because of torque bind.

 

It is possible for the AWD center diff to fail and essentially be "open", but its very uncommon. I'm not sure I've ever even heard of that happening.

 

Try this. Jack up one rear wheel. Trans in gear, try to spin the wheel. You should be able to, but it should be VERY difficult.

If it spins freely, something is missing (part of the driveshaft) or you have a very rare failure of the AWD center diff.

[MilesFox]

Perhaps a broken rear axle

[lmdew]

I've seen the rear half shafts popped out of the diff about 1/2", acts like a slipping clutch on the manual trans.

[84 Bruiser]

Could it be the spare tire fuze ?

[johnceggleston]

 

Could it be the spare tire fuze ?

it's only on the auto trans,

not on the manual trans,

the manual trans is completely mechanical,

no electronics at all..

[roadsubiedog]

ok guys. thanks. will check.

[roadsubiedog]

next night it started shuddering, shaking on right front wheel area from stop to 20mph and then smooth at hwy speed.

 

every time I started from stop it was like that until I hit 20 mph. the shuddering felt like I was going over a rumble strip. it would let up a little when I let up on gas.

 

it drove smooth for about 60 miles at hwy speed and then something broke. a lot of whining and I pulled over and stopped. drove about 10 mph to get over safely and then it just locked up.

 

cant see anything obvious. towed home. it went up ramp OK in neutral on tow truck but when he let it down off the ramp it would buck every revolution even in neutral. I looked underneath while he was letting it down and it seemed to be bucking along the drive shaft near the rear wheels.

 

so I will put it up on 4 jack stands and try to determine the problem . cant see anything obvious.

 

 

 

what kind of tests or procedures should I try to find out what happened?

 

 

 

 

 

 

 

 

 

[Fairtax4me]

Possibly a broken axle.

Whining could be from several things.

Jack it up and check the axles. Spin all the wheels by hand and see if anything strange happens.

[roadsubiedog]

I did that and found the drive shaft broke at the UV joint coming out of the tranny. I posted a new thread on it because of the major failure.i hope I didn't damage the tranny. I turned the front wheels and did not hear any clicking or clunking.

 

can I remove the drive shaft except the part going into the tranny and test drive at slow speed? I know if I take the male end out of the tranny the oil will drain out.

 

I asked on the other thread if I should replace the whole shaft or just the front part and would it be OK to get a replacement from pic and pull? its a 1997 legacy limited with a manual. can other year shaft work with this if they are the same length?

 

thanks in advance.

[lmdew]

95-99 half shafts are the same, some of the newer ones have the ABS ring on the half shaft.  YPAP is fine, just make sure the boots are good and the overall condition is good.  Stick to Subaru Parts is best.