Rear premature wear inner tire

[LF321!]

2013 Edge AWD 41K miles

 

Hi, there is premature tire wear on the inner edge of each of the rear tires. The left (driver) side shows more than the right side. The original tires were replaced at 20K, right before we purchased the car in 2015. There was an alignment done be a Ford dealer 4 months ago, when I originally noticed the wear. It appears to have gotten worse since then, so I doubt the rotation helped. We don't haul heavy items in the car. Could this be a rear shock issue? Any other comments/suggestions would be appreciated.

 

Thanks!

[WWWPerfA_ZN0W]

Certainly sounds like an alignment issue, doubtful it is a tire issue.

Inner Edge/Shoulder Wear

Inner edge (or shoulder) wear occurs on the inside edge of the tire and is usually caused by excessive toe out and/or excessive negative camber. If the tread depth of the outer shoulder is at least 50% greater than the tread depth of the inner shoulder, the tire is experiencing inner edge/shoulder wear. To determine whether tires have this type of wear, visually inspect the tires. In some instances, it may be necessary to measure the tread depth of each rib and compare it to that of the shoulder.

 

2009 Edge Alignment Specifications

Item LH RH Total/Split

Front

Camber -0.1° ± -0.75° -0.6° ± -0.75° 0.5° ± 0.75° ^a

Caster 4.3° ± 0.75° 4.5° ± 0.75° 0° ± 0.75° ^b

Toe — — 0.10° ± 0.20°

Rear

Camber -0.45° ± 0.75° -0.45° ± 0.75° 0° ± 0.75°

Thrust angle — — 0° ± 0.50°

Toe +0.05° ± -0.20° +0.05° ± -0.20° 0.10° ± 0.20°

 

^a Camber Total/Split = LH Camber — RH Camber
^b Caster Total/Split = LH Caster — RH Caster

Do you have the alignment sheet from the ford dealer, so we can see the before & after?

Edited June 26, 2017 by WWWPerfA_ZN0W

[LF321!]

Thanks WWWPrefA_ZNOW, your reply was very helpful. I don't have the alignment sheet from the work done (my bad!) and only have the bill/receipt. It sounds like I can rule out any issues with the rear shocks, correct. Also, I'll get another alignment and replace the rear tires. The Edge is an '13. Would the stats you provided for an '09 Edge be the same? I'll bring a copy of the stats you provided to the dealer.

[WWWPerfA_ZN0W]

Should be very similar specs for the 2013. I will post the 2013 later today. Doesn't seem like shocks based on age/miles, unless you drive on terrible roads. I hope the dealer has the latest alignment machines, I believe they use lasers nowadays. Not absolutely necessary.

[macbwt]

My experiences have been worn rear shocks causing inside wear on the rear tires every time. Check the shocks for a damp or wet area. I have seen this wear as early as 60K miles with shocks. The back up would also be an alignment and wheel bearing check.

[enigma-2]

This site discusses the sources and root causes of premature tire wear on the rear inside edges. (Last paragraph under Toe Wear).

 

http://www.aa1car.com/library/tire_wear.htm

[LF321!]

Thanks for the replies and input. The Edge is going back to the dealer that did the work on 6/30/17. I'll post an update once there's more the report.

[enigma-2]

Must be one of those "back to the future" cars.