E70 X5 Rear Differential failure

[zonefive]

I just purchased a 2012 E70 3.5 XDrive with 70,000 miles, and after I replaced the horrendous run-flat tires I was able to hear a drivetrain whine above 20 miles per hour.

Took it to the mechanic and the rear diff was failing. Almost impossible for him to turn. He took it apart and said the spider gear is bad. All kinds of metal in the oil.

Sourcing a replacement diff from a wrecked car with 14,000 miles on the clock. Total repair cost $1,600 USD. Adding in another $2,600 for deferred maintenance (tires, coolant flush, brake fluid flush, power steering fluid flush, transmission and differentials fluid/filter change, plugs, new battery) and the car should be up to snuff for a while.

Car is in very good shape, doesn't appear to have been abused in any way, the differential may have worked hard in some snowy weather (car is from Chicago), otherwise there's no reason that the diff should have failed. Mine if a post-facelift, is everyone sure that they made changes in the diff when they facelifted the E70?

[ard]

Originally Posted by zonefive

after I replaced the horrendous run-flat tires ?

Which of the 15 different models of run flat tires did you replace?

[zonefive]

Originally Posted by ard

Which of the 15 different models of run flat tires did you replace?

The car had the Michelin Diamaris Latitude tires. Fronts had some tread left, rears were down to the wear bar.

The tires weren't only noisy, they also were very rough riding, made the car feel very choppy and stiff, and they tracked all over the place on the highway -- I thought the car was out of alignment until I put new tires on.

Went with Pirelli Scorpion Verde All Season Plus, H rated, on my 19 inch stock wheels and very happy so far. I bought one of these Amazon.com: Slime 70005 Safety Spair 7-Minute Flat Tire Repair System: Automotive in case I get a flat.

I don't think the engineers appreciated what the run-flat tires would do to the ride when they made the decision to delete the spare (I have third row).

The car is so nice otherwise, it makes me wonder whether the terrible ride and noise was the reason the prior owner traded the car in (he bought a new Lincoln Navigator).

FYI, my used rear diff was $1,000 less that the remanufactured one from BMW -- definitely a better choice IMO.

[gregg3gs]

Originally Posted by zonefive

I just purchased a 2012 E70 3.5 XDrive with 70,000 miles, and after I replaced the horrendous run-flat tires I was able to hear a drivetrain whine above 20 miles per hour.

Took it to the mechanic and the rear diff was failing. Almost impossible for him to turn. He took it apart and said the spider gear is bad. All kinds of metal in the oil.

Sourcing a replacement diff from a wrecked car with 14,000 miles on the clock. Total repair cost $1,600 USD. Adding in another $2,600 for deferred maintenance (tires, coolant flush, brake fluid flush, power steering fluid flush, transmission and differentials fluid/filter change, plugs, new battery) and the car should be up to snuff for a while.

Car is in very good shape, doesn't appear to have been abused in any way, the differential may have worked hard in some snowy weather (car is from Chicago), otherwise there's no reason that the diff should have failed. Mine if a post-facelift, is everyone sure that they made changes in the diff when they facelifted the E70?

I like the way you think. So did I, until this happened:


http://www.xoutpost.com/bmw-sav-foru...xel-today.html

Good that you found this early.