Manual Trans. Thud when shifting

[souprmage]

I notice mine mostly going into 3rd. It seems to 'thud' a bit louder than the others even though it's there for first and second as well. Sounds like a synchro engaging to me. I'm at 700 miles so far.

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[DJGold]

Just to shed some light on this... I have a manual V6 and it also thuds slightly. So it's not just the GTs or PPs.

 

[MikeSVTGT]

i have been listening for it in my car since i have read other accounts, and i am just not hearing or feeling anything. she shifts as smooth as butter for me.

+1

I have the same transmission in my 2011 GTCS and my 2015 LE shifts much smoother.

 

[MustangDirector]

This issue is actually more about a noise than the smoothness of shifts. Mine shifts smoothly also, but has a slight thud when shifting into certain gears. I have driven three 2015 GTs and they all made the noise to varying degrees.

 

[franklin9150]

Count me in as a member of the thud club. I've heard it since I first drove it off the lot. I'm not concerned.

 

[Patrick S]

i think all our PPs are broken.

:lol:

that was not nice, since i was sipping my coffee when i read that.

 

[Asharus]

Lol

 

[fionic]

I've noticed a thud, but only after I was in 3/4/5/6 gear back down to 1 or 2 (like after a stop light or stop sign). I'm guessing it has something to do with how it articulates (it bends in the middle instead of a straight piece).

see what I mean in these videos

http://www.mustang6g.com/forums/showthread.php/mgw-first-look-4299.html

 

[Seabee1973]

I only see it going in first from neutral

 

[Seabee1973]

Normal mode seems difficult for me though sport+ is smoother.... now though.... Normal is getting smoother. Completely different coming from an Audi

 

[souprmage]

Normal mode seems difficult for me though sport+ is smoother.... now though.... Normal is getting smoother. Completely different coming from an Audi

Snow/Rain mode is a pain in the butt from a stop. I keep stalling it. I finally just gave up and only use Normal mode in the rain. I suppose Snow/Rain may be good for really slick conditions, but normal rain conditions, not so much.

Sport+ is way easier and I too am getting smoother with Normal.

 

[Demon Coyote]

I've been talking to Ford service for a while about this and to my dealer as well. My dealer claims it is normal since it is in all cars. But I read on another forum that in the previous MT-82 they added the XL-18 friction modifier and it made things smooth as butter. Hoping to have that added to my trans sometime soon as well as the XL-3 friction modifier for the diff as I notice the rear end making a slight clunk/thud sound when I come to a stop and then make a slow turn. The noise comes while I'm making the slow turn only.

 

[DivineStrike]

My main issue with this thud, is it occurs when completely stopped. To me that indicates the clutch isn't fully disengaged. I understand there is pressure in the transmission pushing transmission fluid through the tranny but what else could be making the thud?

 

[Barrel]

My main issue with this thud, is it occurs when completely stopped. To me that indicates the clutch isn't fully disengaged. I understand there is pressure in the transmission pushing transmission fluid through the tranny but what else could be making the thud?

I'd be willing to bet that if you waited long enough, you wouldn't get the thud. It's my understanding that there are components spinning inside the trans that you engage when shifting to first. If you shift to first then second then back to first, is the thud still there? It should only thud the first shift.

 

[aeropaul]

My main issue with this thud, is it occurs when completely stopped. To me that indicates the clutch isn't fully disengaged. I understand there is pressure in the transmission pushing transmission fluid through the tranny but what else could be making the thud?

At idle, there isn't any pressure pushing fluid through the trans, it's a lubrication bath.

The clutch may be fully disengaged, but input shaft of the transmission may still spin in neutral until a mechanical resistance is applied (shifting into first) due to aerodynamic forces inside the clutch mechanism. If it's in neutral with the clutch out, then you push the clutch in, the input shaft will still spin for a time because it carries some rotational inertia, until you slam it into first.

During all of this, one half of the synchronizer assembly is spinning at idle RPM (or slightly lower since you pushed the clutch in a half-second ago), and the other is stationary.

When shifting while the car is moving forward, one half of the synchro assy is moving at engine speed, the other is moving at wheel speed X Rear gear ratio.

The whole thud-while-shifting is not a transmission internal component issue, it has more to do with the stiffness of the transmission mount and shifter mount to the body of the car transmitting feedback from the synchro units back into the body and cabin.

Google "transmission synchronizer" to see the details of how these work. If someone has a better theory, feel free to put it forward. If you're having grinding, hard-to-engage gears, or missing shifts, then you have a problem. This is just a NVH issue inherent with the remote shifter design as far as I'm concerned. More likely a by-product of beefing up the shifter mounting design due to issues with the 11-14 cars. I also read somewhere that Ford had Getrag beef up the synchros for the '15, so there "shouldn't" be an issue there anymore.

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