Violent Shaking From Shifter

[Dadams]

Hello, I have a 2018 gt pp1. Only aftermarket mod is a corsa catback. The issue I’m currently having is a violent shake/metal on metal sounding rattle from the shifter under load, doesn’t have to be a heavy load, just about anything over 30% throttle. Doesn’t occur in 1st or 5th gear at all but does in all the others. In 3rd gear once i get to about 2k rpm it doesn’t shake/vibrate anymore. It’s loud enough that you can hear it from the outside of the car. Just to clarify, it’s not the whole car, just the shifter but when I’m 2nd if I try to apply a heavy load the car does feel like it’s bogging. I wasn't beating on the car when it happened, just drove it to work and then on the drive home is when it started happening. So my best guess is that a nut or bolt walked itself out? But I’m not sure where to start looking. Also, shifting gears is fine no issues there. I would go to a dealership but every dealer near me is a month out before they can look at it
Thanks

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[Skye]

You can start with the obvious: get under the car when you have a moment and visual inspect, put your hand on everything, front-to-back.

Miles on car? Any previous damage? Good maintenance?

Could be something in the transmission, but you mention you're shifting OK. Could be a vibration from the suspension/drivetrain traveling through the car. Once up to speed and holding it there, do the vibrations continue, or, is it only under load?

 

[Dadams]

You can start with the obvious: get under the car when you have a moment and visual inspect, put your hand on everything, front-to-back.

Miles on car? Any previous damage? Good maintenance?

Could be something in the transmission, but you mention you're shifting OK. Could be a vibration from the suspension/drivetrain traveling through the car. Once up to speed and holding it there, do the vibrations continue, or, is it only under load?

Yeah, I plan on getting underneath it later today. 35k miles, first owner complained about the transmission, ford bought it back and I was told they installed a new transmission. I got the car around 28k miles, good maintenance. I haven’t tried just holding it, except for in 6th gear. I was holding it at about 80mph and it was a constant vibration. As far as any acceleration goes, 2nd gear if i go light on the throttle it doesn’t happen, otherwise it gets really bad. 3rd gear is the same way until after 2k rpm, then it’s completely fine. 4th isn’t as bad as 2nd, but there’s still a constant vibration when accelerating. 5th gear it doesn’t occur at all. 6th gear is about as bad a 2nd gear

 

[Skye]

Are you close to the dealer that bought the car back and replaced the transmission? That would be sweet. A lot of information could be gleaned.

The shaking problem just revealed itself, yes?

1. Even though it is a month-long wait, I'd schedule an appointment now. You can always cancel it.

2. If you do discover anything obvious, photograph and document it. I wouldn't touch it at that point, because...

3. Have you had a conversation with the dealer about warranty support? I'd like to think with the information given thus far you have something of a warranty.

 

[Dadams]

Are you close to the dealer that bought the car back and replaced the transmission? That would be sweet. A lot of information could be gleaned.

The shaking problem just revealed itself, yes?

1. Even though it is a month-long wait, I'd schedule an appointment now. You can always cancel it.

2. If you do discover anything obvious, photograph and document it. I wouldn't touch it at that point, because...

3. Have you had a conversation with the dealer about warranty support? I'd like to think with the information given thus far you have something of a warranty.

No, I purchased it in Kansas and I’m in central Illinois unfortunately haha. Issue just presented itself recently, I’m gonna call around today and see how can get me in the quickest. I will for sure document it, because I can’t find anyone with a similar issue or a certain idea what might’ve happened. Yes, I have a warranty. I’ve been avoiding just giving the car to a local shop, but wanted to see if I could figure it out myself without messing anything up

 

[Dadams]

I had some time to get under the car today, so far I found two issues I’ll start with. There’s a bolt missing from the top of the driveshaft and there’s a leak on the trans mount but I couldn’t find where it was coming from

 

[Cobra Jet]

Whatever you do - don't go driving it anymore with a missing driveshaft bolt. If one is missing that's an issue of itself... because driveshaft bolts shouldn't just be falling out.... check torque of ALL other remaining driveshaft bolts.

Driving around like that will and can lead to detrimental failures of either driveshaft, cracking the gearbox case, or worse case scenario, cracking/damaging the engine block.

--

Was that trans ever serviced before? Maybe it's me, but the trans mount bolts (to me) look like they have been R&R'd by someone and not just the initial assembly line install... Usually initial factory assembly, the heads of bolts don't look tampered, because almost every one is installed by either a bot or a person using a specified tool with predetermined torque settings that won't mar the bolt heads.

 

[dbtgt]

I had some time to get under the car today, so far I found two issues I’ll start with. There’s a bolt missing from the top of the driveshaft and there’s a leak on the trans mount but I couldn’t find where it was coming from

It seems likely to me that the vibration is caused by the missing bolt on the driveshaft flange.
The sudden appearance of the vibration is likely due to the bolt falling out IMO.
It would cause an unstable coupling that would vibrate under certain load and speed conditions.
I think this needs to be remedied right away.

 

[Dadams]

Whatever you do - don't go driving it anymore with a missing driveshaft bolt. If one is missing that's an issue of itself... because driveshaft bolts shouldn't just be falling out.... check torque of ALL other remaining driveshaft bolts.

Driving around like that will and can lead to detrimental failures of either driveshaft, cracking the gearbox case, or worse case scenario, cracking/damaging the engine block.

--

Was that trans ever serviced before? Maybe it's me, but the trans mount bolts (to me) look like they have been R&R'd by someone and not just the initial assembly line install... Usually initial factory assembly, the heads of bolts don't look tampered, because almost every one is installed by either a bot or a person using a specified tool with predetermined torque settings that won't mar the bolt heads.

Dropped the car off at a dealership yesterday, they said they should be able to get a look at it today. Not while I’ve had it, and I can’t find the previous owner’s service records at the moment. I also noticed those bolts when I was showing another mustang owner so hopefully the service records will show something that ties to that.

 

[bnightstar]

Had a similar oil leak from my MT82 but was a cheap bearing replacement. Looks like yours could be the same.

 

[Skye]

Dropped the car off at a dealership yesterday, they said they should be able to get a look at it today. Not while I’ve had it, and I can’t find the previous owner’s service records at the moment. I also noticed those bolts when I was showing another mustang owner so hopefully the service records will show something that ties to that.

Happy to hear you got it in and things are still under warranty. Sounds like you caught it just in time.

Now...did the original problem return because 1) the root cause was not correctly identified, or, 2) the repair technician did not fix the issue correctly the first time? The new team and a fresh pair of eyes should help.

 

[paulm1]

Missing bolt, unbalanced driveshaft, vibration at the yoke let oil past the output seal, that's my guess on the leak.

 

[TeeLew]

I bet your exhaust is touching the trans crossmember under load. It makes a hell of a noise, but it's an easy fix.

 

[Dadams]

The dealership was really back up so it took a while for them to get it on the lift. I’m not sure if it was service from the previous owner or maybe when I got my 30,000 mileage service, but a tech left the nuts on the trans mount bushings loose and then there was also the bolt missing from the driveshaft. After addressing those issues the car drives completely fine

 

[Ninpop9]

The dealership was really back up so it took a while for them to get it on the lift. I’m not sure if it was service from the previous owner or maybe when I got my 30,000 mileage service, but a tech left the nuts on the trans mount bushings loose and then there was also the bolt missing from the driveshaft. After addressing those issues the car drives completely fine

I have a family member whos been a master tech for decades that teaches automotive at top trade schools. The number one issue that he sees today is kids getting into the trade that aren't really interested in cars in comparison to his time in school. Lack of workmanship at dealerships really suck.

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