Loose lug nuts on stock rim

[rayu]

I took by 05 LGT Limited 5MT wagon to Quirk Subaru in Quincy, MA this morning to have the wailing, prone-to-failure rear bearings replaced under the factory extended warranty for them. I was surprised to get a call from the service department that said that my passenger rear wheel had come loose and the mounting holes had been elongated, necessitating wheel replacement (anyone have a single rim to sell?).

 

This wheel is the stock painted alloy wheel which I run my snow tires on. I changed-over the wheels myself over Thanksgiving weekend, meticulously tightening them in the recommended cross pattern with a torque wrench to the Subaru recommended torque setting. Lug nuts are stock.

 

What could have caused the loosening in this one wheel? Could the failing wheel bearing have added vibration? It's very strange. I guess I'm fortunate that it was caught before the wheel came off. I was involved with one of those incidents at 65 MPH on the Mass Pike when a prominent Boston area tire retailer failed to tighten the lug nuts on my GTI. It was scary to see the wheel bouncing across 5 lanes of heavy traffic as I slid to a stop on the front brake rotor. Thank God the wheel hit nothing on the way to the other side.

 

Needless to say, I'll take the torque wrench to all of the remaining lug nuts tonight.

[devobuzz]

Did you oil/grease the studs???

[fonts]

Generally it is recommended to re-torque (ie. a 2nd time) your lugs approx. 75 miles or so AFTER wheel re-instalation and original torque.

[mwiener2]

I changed-over the wheels myself over Thanksgiving weekend, meticulously tightening them in the recommended cross pattern with a torque wrench to the Subaru recommended torque setting.

 

 

if you went anything less than 80ftlbs, you read the wrong manual

[rayu]

A number of sources recommend the second tightening after some miles of driving. I've never done that, but will from now on. The theory, which makes sense, is that if something is preventing full seating of the wheel on the hub, the driving will settle things and show loose lug nuts. Never used lubricant on the threads and I set the torque wrench to 110 N-m, which is 81 ft lbs. The stock LGT rim proved to be very rare; not a single one in greater Boston. I'm having a remanufactured one shipped in from Detroit Wheel and Tire; $175 plus $27 shipping.

[mikeislord]

Never hurts to periodically check the torque on your lugs. I've had a couple of loose lugs in my lifetime, one actually coming off. As long as you aren't putting additional force on the lug, you shouldnt do any damage.

[Magruder]

Just had all 5 of the lugnuts on the passenger rear tire loosen up about 500 miles after a tire rotation. My mechanic told me that altho he hand-torqued them to 81 ft/lbs, they had to be re-torqued in a week or so, and I assured him I would do it. I didn't. On a 700 mile trip, started hearing and feeling a rumble/vibration that seemed to come from the passenger front. Stopped and checked lugnuts, and surprisingly, found all five on the passenger rear wheel at least 1/2 to 3/4 turn loose. Haven't yet looked at the holes in the wheel to see if elongation is present. Beware! 45K miles, second set of tires.