Ok, here's my latest saga (after my intermittent starting problem). Since I purchased my '04 XF almost a year ago, I have been hearing a "humming noise" from the rear end. It was really noticeable at higher speeds especially when pressing and releasing the gas petal. After researching this issue on this forum, I took it to one dealer who said "don't worry about it" which was not the answer I wanted to hear; I wasn't "worried" but knew it was right to be making the noise. I took it to a second dealer who said it was a common problem with the differentials on some of the earlier XF's. They ordered a new one which turned out to be on "nationwide backorder" and it took about 7 weeks to get it in. Thankfully the car was driveable and the problem was really just annoying. When the part finally came in, they called and the repair was promptly made. I picked up the car and proceeded to drive about 3 miles when I heard a BANG, then a THUD, and finally just GRRRRRR and my baby died beside the road. The spot where it happened to die was on the Washington DC Beltway, right at the exit to Rt. 66 West. This is about the last place anywhere that you want to break down. Anyway, needless to say I was not pleased (understatement). I called the dealer immediately and within 30 minutes they sent their Courtesy Van to pick me up. They also made arrangements to have a flatbed tow truck pick up my XF. They gave me a loaner (300 Touring) and ordered another differential. It took 8 days for the new part to arrive and be installed. This time I told the service manager to drive the car home and back before they declared the problem solved. On the day it was ready, he called to confirm that it was ok for him to drive the car home and back and I told him "yes" it was. The next day I picked up the car and it is running fine and, best of all, the "humming noise" is gone. All I hear when I accelerate is the sweet sound of the exhaust.

In the end, Koons Chrysler in Tysons Corner, Virginia, got the job done. It took patience from all parties, we worked together, and we kept smiling even though there were times when I could have really lost it. I was able to speak directly to the XF tech who was really at a loss to explain what happened (and yes, he assured me that there was oil in the differential). All they could say was it was a defective part. I do have the MaxiCare warranty which is a good thing because the total bill for the work was $3,300 (and they did it TWICE). Out of pocket cost was $100. Even with what happened, I would not hesitate to take my XF or other cars to them for service. (FYI, they only charge $75.47 for an oil/filter change on the XF.)

 

That's awesome. I'm glad to hear they got you taken care of and it sounds like the MaxCare warranty was a good move.

 

It always gladdens my heart to hear a story about a dealer doing the right thing!

 

Hi, I have the problem with my differential seems the same as yours, but the noise I heard was a metallic pop (I also have the harmonic hum you mentioned). My car has around 17,500 miles. Is your car still running well after 8 months later?

Thanks for any further input.

Don

 

With the exception of a burned out headlight bulb, I have had no problems with my XF since then. I think it now has about 57,000 miles on it.

 

Thanks for responding I am happy to hear that the car is working well for you! My car is a the dealership now awaiting a new differential to be installed under warranty.

A concern I do have is I wonder if any other tranny items need to be replaced or just the differential?

Don

 

Fenwick did you by any chance find my thread on this matter? I too after a frustrating ordeal ended up at Koons of Tysons and they did the job. I am glad to see you got this problem solved. Not only is it annoying as hell to listen to, but its frustrating because the dealers won't believe you. I actually went for a drive with their XF tech, nice guy but I can't remember his name. Member: Bobs was also a big help when I was figuring out how to resolve this issue.

 

Just took mine to Harry Lane Chrysler in Knoxville for overheating prob. and mentioned the whining rear end. We'll see what they say. BTW, mine has been whining since new. I thought it would quiet down as it got broke in, but it is getting louder. 16,000mi on it now.

 

I took mine to Koons in Tysons Corner after reading about another forum member's experience with them. Maybe it was your post, mrobinso! The tech was a good guy - if I remember, and Eastern European (Serbian maybe?) who was a trained MB tech and also an XF tech and was genuinely embarrassed when the first replacement rear end failed. As far as I know, nothing else was replaced except the rear end - no other tranny parts - and that is confirmed by the service receipt.

 

Just to be clear with everyone-

My issue started as a metal popping noise. When I was slowing down with no load on the transmission I would hear a metal pop.

After taking in to the dealer- they reported back that my rear differential is bad and they are replacing it under warranty. My car has approx 17,500 miles.

My question is would anything else possibly need replaced, such as rear end u joints etc?

Thanks

Don

Update 9/6/08

Picked up the Xfire yesterday, they did a nice job of not trashing my baby.

They replaced the rear differential under warranty- I don't have the same loud metal pop sound everything is smooth and quiet.

However-

After my 30 mile drive back to the house- upon slowing down I heard a faint metal pop sound, this time the noise is on the driver side rear wheel area.

The sound before replacing the rear differential was in the center area of the car.that sound is gone... dissapointed I drove around the block three times just to listen, it happens when I am slowing down with no load on the drivetrain, and I really think the noise is coming from the rear wheel area.

Any thoughts. I am going to drive it again today to listen for the noise.

Thanks

Don