05 Outback Rear Wheel Issues

[delli50]

i have an 05 outback - 4cyl, auto, 250,000 kms.  It's been a great vehicle but there are 2 issues that i have noticed recently.  i don't think they are related but i would like to hear about other members experiences and thoughts on my issues with the rear wheels.

 

first issue is that this wagon wears out tires fast.  probably in under 30,000 kms - that's under 20,000 miles.  the wear is very even and i first notice it on the middle rib of the tire.  the car has never been hit and has had recent alignments.  the rear tires wear much faster than the front ones.  i also have an 06 forester and i dont see tire wear on that vehicle like i do on the outback.

 

second issue is that i have had to replace numerous wheel studs on the rear wheels.  this has happenend a number of times.  this week there were 2 broken studs on the left rear.  also when i went to remove the right rear wheel the acorn lug nut cam off and when i removed the wheel a piece of one of the studs fell off.  i replace them with parts from a local supplier who seels dorman wheel studs to me.  they are american made and dorman is supposed to be a good maker.

 

both of these issues puzzle me.  anyone else ever experience this?  any thoughts?  no sense in me asking the dealer as they are always less than helpful.

 

regards,

 

mark

[montana tom]

Have you owned the car since new, or is it a recent acquisition ? Has it worn tires that quickly since you owned it ? Are you the only driver or is there a teenager in your home? Have the front & rear differentials  had the oil level checked ?  Broken studs and worn rear tires make me think of a teenager (however old) who is rally driving ... using the parking brake to lock up the rear end, snapping studs with side load.... ripping up everything like your wagon was a wrx. 

[delli50]

some more information...

i torque the wheel nuts at 100 foot pounds.  the car is not rallied or driven hard.  it is my daily driver and driven responsibly.  i am the second owner.  i bought it at about 190,000 kilometres.  i have had 2 new sets of tires in it since.  the tires wear very rapidly.  the wheel stud issue is separate from the tire issue, i think.  also, i am only breaking wheel studs in the rear.

 

mark

[Fairtax4me]

i torque the wheel nuts at 100 foot pounds.

This may be the reason you're having trouble. Over tightening lug nuts stretches the lug studs and can gall the threads. This will be worse with aftermarket wheel studs. I recommend new wheel studs and new lug nuts from Subaru.

FSM for that car specifies 81 ft-lb wheel nut torque.

 

Wear in the center of the tire usually indicates over-inflation.

What pressure do you run in the rear tires? What pressure is recommended on the tire info placard?

 

You've had it aligned, but did you ask specifically for a 4 wheel alignment? Some shops adjust only the front wheels when doing an alignment.