Vibration between 50 & 70 mph

[Dominant1]

Here's an update: Ford authorized a replacement complete differential assy. Parts scheduled to arrive tomorrow. Stay tuned.....



Dominant1, were you able to get the balance masters balancer installed?

no not yet maybe the weekend if i have time...

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[shelbywannabe]

Did you ever get it resolved or are you just living with the vib?

After a full summer of Ford switching out parts and it never getting any better at all I got rid of the car and bought a Challenger SRT 392
I loved the Mustang but I just lost the desire to keep it as it vibrated all the time. Considered getting another but decided to not risk it

 

[boardkat]

finally root caused and solved my vibration problem. when i swapped out my aluminum diff carriage for offseason maintenance last weekend, and put my stock low mileage iron case back in, vibration at all speeds ceased. upon further inspection of the case after disassembling, i found a bad carrier bearing and slight case deformation. i should have known better, especially since i broke two carrier bolts at a race this season, most likely causing the issue. so i know for most this won't be helpful, but for those of you driving your car extremely hard like me, it may be worth investigating if driveline angles and driveshaft balance are good (mine were).

 

[2007GT500]

I got rid of my my vibrator, 2016 Mustang GT, 8 months ago. Traded it in on a 2017 Challenger Scat Pack 392 Shaker. Problem solved...

The 392 may be big but it is fast in a straight line. On Saturday I ran a 12.11 at our local drag strip. Only mod was a set of DR's.

 

[Dominant1]

I got rid of my my vibrator, 2016 Mustang GT, 8 months ago. Traded it in on a 2017 Challenger Scat Pack 392 Shaker. Problem solved...

The 392 may be big but it is fast in a straight line. On Saturday I ran a 12.11 at our local drag strip. Only mod was a set of DR's.

Hey that’s a only few 10ths slower then a stock 2018 mustang on street tires with 25 less hp...lol

 

[2007GT500]

LMR ran 11.88 on a drag wheel set up and 2 other minor mods. I have not seen anyone run under 12.0 on street tires. Maybe I missed it. Hopefully the 2018 does not vibrate like the 2015-2017. I owned 2 s550's and they both vibrated. Out of pure frustration I bought the Scat Pack as a daily driver. I have owned 16 Mustangs and still have a 2007 GT500. I am a Ford fan and if the 2018's don't have the drive line issue then there is a good chance I will own one in the future. Just pointing out the Scat Pack is very fast for a heavy car.

 

[usgiorgi]

Hey that’s a only few 10ths slower then a stock 2018 mustang on street tires with 25 less hp...lol

As a scat pack owner, I gotta tell you that people run 11.9s with drag radials and good conditions on otherwise 100% stock chargers and challengers. This is with the 8spd auto.

The 2018 Mustang has 10 speed auto which is the reason why it's so fast. It shifts blazingly fast and the gearing makes even better.

A manual 2018 Mustang will be in the mid 12s and maybe low 12s with a good driver.

 

[Sash]

wow this for real turn me of mustang, i almost pull a trigger on 17,thank god i didn't, i have to wait and see if the 18 will have the same problem, from what i see the share the same drive line .........

 

[Dominant1]

As a scat pack owner, I gotta tell you that people run 11.9s with drag radials and good conditions on otherwise 100% stock chargers and challengers. This is with the 8spd auto.

The 2018 Mustang has 10 speed auto which is the reason why it's so fast. It shifts blazingly fast and the gearing makes even better.

A manual 2018 Mustang will be in the mid 12s and maybe low 12s with a good driver.

Ahh your forgetting that hp to weight is the biggest factor on et’s not the trans. if the challenger weighed 3500 lbs with its current power it would run 11.5’s all day long! You can’t use a better trans as an excuse to be slower then the stang you gotta blame the extra heft those cars carry! The zl1 beats the hellcat not because of its 10 speed auto it’s because the hp to weight ratio is better!

 

[usgiorgi]

Ahh your forgetting that hp to weight is the biggest factor on et’s not the trans. if the challenger weighed 3500 lbs with its current power it would run 11.5’s all day long! You can’t use a better trans as an excuse to be slower then the stang you gotta blame the extra heft those cars carry! The zl1 beats the hellcat not because of its 10 speed auto it’s because the hp to weight ratio is better!

Sure, these things are insanely heavy. However, try running similar times with a stick shift vs 10 or 8spd auto and then report your findings. You'll see that the auto shaves off a few 10ths off your time.

 

[Dominant1]

Sure, these things are insanely heavy. However, try running similar times with a stick shift vs 10 or 8spd auto and then report your findings. You'll see that the auto shaves off a few 10ths off your time.

Last time i looked mopar has a good 8 speed auto with two less gears, i doubt that its that much a factor auto vs auto, its the weight. Think about your 25 extra hp and dr’s cant overcome the weight your car carries! You think if you had a 10 speed it would be better? I think not. Its the weight of mopars that holds them back, not the 8 speed auto!

 

[barrykaye1001]

Update: got the car back last night. They found a vibration of 48hz at 51mph. They removed the rear diff and found that there was backlash at .021. They disassembled the diff and found an uneven wear pattern in the carrier bearings which had "excessive runout." They replaced the entire rear axle assy.

Three people road tested it and said it's smooth as silk. Mmm-hmm. I drove it home and while it is about 95% cured, it ain't smooth as silk. :frusty:

Waiting to see how [MENTION]Dominant 1[/MENTION] does with the balance masters balancer. I'm thinking that might get it to 100%. Stay tuned....

 

[1024GT]

Is ford entertaining anything for folks with mods?

 

[ABS550]

Hmmm

Update: got the car back last night. They found a vibration of 48hz at 51mph. They removed the rear diff and found that there was backlash at .021. They disassembled the diff and found an uneven wear pattern in the carrier bearings which had "excessive runout." They replaced the entire rear axle assy.

Three people road tested it and said it's smooth as silk. Mmm-hmm. I drove it home and while it is about 95% cured, it ain't smooth as silk. :frusty:

Waiting to see how [MENTION]Dominant 1[/MENTION] does with the balance masters balancer. I'm thinking that might get it to 100%. Stay tuned....

I am not an expert on this, but I would really wonder what made the carrier bearing have the excessive runout. Was it this way from the start. (unlikely) Or, was there something else that was out of balance (like the DS) which wore out the carrier bearing? If you think there is still a vibration, then it may take its toll over time on the new rear axle assembly. I would make sure the DS is balanced, just to make sure.

 

[CtheProducer]

That is my main concern with it being "Fixed" now, but Ford originally telling me "Just drive it, nothing is wrong".
What all has become worn out only to fail over time from all the vibration from an out of balance Drive Shaft.

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