Can struts/springs cause very bad inner rear tire wear?

[idosubaru]

2006 Tribeca both rear tires are wearing heavily on the inside edge/corner.

It doesn’t appear that rear camber is adjustable.  

There’s no movement in any rear bushings and no rust (bought this car in the south).  

At 200,000 miles the struts and springs are probably original and the roads here are atrocious and rough. The ride is definitely rougher than stock on bad roads but not really noticeable on normal roads.

The generic answer is ‘yes’, but ive never seen struts cause tire wear issues on Subaru’s. Do old rear springs/struts cause this routinely?

Edited August 20, 2019 by idosubaru

[1 Lucky Texan]

I'd look for something causing toe problems. could be something only happening 'dynamically'.

 

dunno much about how to do that....

[idosubaru]

I pried on points while in the air and nothing moved, but suspension isn’t my thing.  

Maybe someone knows if this is something that happens to Subaru’s sometimes.....or never?

lifting Subaru’s increases camber and outer edge wear, so it seems geometrically resonable to guess the opposite may happen if the rear lowers and the hub follows that same arc?  But I never saw the famously saggy older rear Imprezas do that, but they’re already low to the ground...?

Needs them anyway so I’ll start with struts and maybe springs and hope someone can recommend something before I burn another set of 18” tires!

[1 Lucky Texan]

yikes,

I bet you get it fixed, fingers crossed

[Numbchux]

Well, if the rear is sagging, the camber will go more negative on the both multilink designs. Older Imprezas are all modified-Macpherson rear, which has much more consistent camber through the travel.

Do you regularly drive it loaded? If so, overload springs (I'm not sure if that's even a thing on a Tribeca...) might be worth looking into.

[idosubaru]

1 hour ago, Numbchux said:

Well, if the rear is sagging, the camber will go more negative on the both multilink designs. Older Imprezas are all modified-Macpherson rear, which has much more consistent camber through the travel.

Do you regularly drive it loaded? If so, overload springs (I'm not sure if that's even a thing on a Tribeca...) might be worth looking into.

"loaded" - not construction equipment, rocks, or a boat - but many many thousands of miles a year with 450 pounds of people, plus bags, bike, kayaks.  is that "loaded"?

Okay that makes sense - since I have an issue I'll go ahead and replace the springs and struts as well.  Thanks for chiming in, I was just about to order the parts.

[Numbchux]

2 minutes ago, idosubaru said:

"loaded" - not construction equipment, rocks, or a boat - but many many thousands of miles a year with 450 pounds of people, plus bags, bike, kayaks.  is that "loaded"?

Okay that makes sense - since I have an issue I'll go ahead and replace the springs and struts as well.  Thanks for chiming in, I was just about to order the parts.

Yea, I was assuming you weren't putting 2000 lbs in it....it should be able to handle 450ish.

 

I think there are still ride height measurements in the FSMs. Might be worth seeing if it's officially sagging before you go buying springs.

[idosubaru]

21 minutes ago, Numbchux said:

 

I think there are still ride height measurements in the FSMs. Might be worth seeing if it's officially sagging before you go buying springs.

Thanks - just measure it, with no weight in it it's exactly 1" lower than FSM spec's. 

All 4 FSM responses to "improper vehicle posture or wheel arch height" involve replacing the strut and/or spring.  Interesting it doesn't mention bushings as even a possibility. 

Edited August 20, 2019 by idosubaru