Rear end knocking sound

[kellyreno]

Not a good day for my Mach 1. Dropped off at the dealer for an estimated 3 day job. Knocking sound from right rear axle. Service rep said "play between axle and differential" have to pull the entire "New torsen" rear end. 1 yr old and 6000 miles?? Concerned about long term issues. I asked if I could be a clutch pack and was told no. Anyone have similar issue?

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[K4fxd]

Not much in there to cause play. I suspect a missing or damaged cir-clip.

 

[kellyreno]

Not much in there to cause play. I suspect a missing or damaged cir-clip.

They said no safety issue, I could continue to drive. Seems odd?

 

[NGOT8R]

Any video of the knocking?

 

[kellyreno]

Any video of the knocking?

No, again I thought it was the nail hitting the tire. Windows were down on a nice spring day, not loud at all. Now, I seem to hear the clunk when shifting from reverse to drive going uphill. Why 3 days, you would think it could be done more quickly unless parts are needed. Dealer has 30 bays.

 

[NGOT8R]

Did it sound like this?

 

[5-OH]

Not a good day for my Mach 1. Dropped off at the dealer for an estimated 3 day job. Knocking sound from right rear axle. Service rep said "play between axle and differential" have to pull the entire "New torsen" rear end. 1 yr old and 6000 miles?? Concerned about long term issues. I asked if I could be a clutch pack and was told no. Anyone have similar issue?

I was also told I cannot be a clutch pack, but effthem I can be anything I want to be.

 

[kellyreno]

Did it sound like this?

wow that looks really loose. what was that?

 

[NGOT8R]

wow that looks really loose. what was that?

It’s called drivetrain backlash. All cars have it, although some may be worse than others, especially if a rear end hasn’t been properly set up during assembly.

 

[cop on my back]

Can't be a clutch pack, Torsen rear ends don't have them. Completely different way to have limited slip. Google Torsen.

 

[kellyreno]

Not a good day for my Mach 1. Dropped off at the dealer for an estimated 3 day job. Knocking sound from right rear axle. Service rep said "play between axle and differential" have to pull the entire "New torsen" rear end. 1 yr old and 6000 miles?? Concerned about long term issues. I asked if I could be a clutch pack and was told no. Anyone have similar issue?

Well, I picked her up after 3 days. The dealer said this: Seems strange how an axle could be "not seated"?

 

[Jstang23]

Well, I picked her up after 3 days. The dealer said this: Seems strange how an axle could be "not seated"?

I'm not sure how a half shaft that wasn't seated properly for 6k miles caused no addition damage. I would have another shop look at it just to be sure and if there is bring that to ford. Never trust dealer assessments, usually just a kid with a high school diploma who can turn a wrench working on those unfortunately.

 

[kellyreno]

Well, I took a road trip of 240 miles and rolled over 8,000 miles. However developed a vibration on the interstate. Comes on about 70 mph and stops around 80 mph. First noticed in the rear view blurred vision. Also the door panel but not in the wheel? First thought wheel weight, nothing there. No codes, not RPM related? Thinking drivetrain because of the narrow mph range. Tranny or driveshaft. I need an oil change so the next stop is the beloved dealer. I wonder if other Mach 1 drivers had a similar issue. I keep thinking about my rear axle that took 3 days to repair.

 

[GTP]

Well, I took a road trip of 240 miles and rolled over 8,000 miles. However developed a vibration on the interstate. Comes on about 70 mph and stops around 80 mph. First noticed in the rear view blurred vision. Also the door panel but not in the wheel? First thought wheel weight, nothing there. No codes, not RPM related? Thinking drivetrain because of the narrow mph range. Tranny or driveshaft. I need an oil change so the next stop is the beloved dealer. I wonder if other Mach 1 drivers had a similar issue. I keep thinking about my rear axle that took 3 days to repair.

I think @K4fxd nailed it with the inner end circlip.

Now, for the vibration, head on over to the famous driveshaft vibration thread. It is super long now. But, it could be that the dealer disconnected the driveshaft for troubleshooting, and did not reconnect it at the same clock orientation. Jack up your car and crawl under there to see if the paint marks match at both end of the driveshaft.

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