Manual Trans. Thud when shifting

[Ryan1112]

We already know it's the synchronizers in the transmission that make the sound. The changes made to the transmission for 2015 seem to have created more noise and they were not completely damped. When you shift gears the syncros that are rotating at different speeds connect and make the thud sound/vibration that is transmitted to the transmission case, then through the shifter and transmission mounts, then to the chassis, then through the cabin, then to your ears. The thud will be a little louder in cars with the PP because of the 3.73 gear.
You will typically hear the thud the loudest from 1-2 shifts, 2-3 shifts, or from neutral into any gear depending on the speed of the synchros at the time. Although you may still hear the sound from 3-4, 4-5, and 5-6 shifts, it is less likely beceause they are closer to 1 to 1 gear ratios.
Shifting technique, double clutching, or adding a transmission bushing can help a little because the synchros won't be hitting and changing speed as abruptly.
This is what I think is going on and when I took my car to the dealer they verified it.
There is technically nothing wrong with our cars. I'm sure Ford is aware and will probably try to damp the sound better for future models and probably issue a TSB if they come up with a feasable solution to quiet the sound.

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[Rv-Junke]

We already know it's the synchronizers in the transmission that make the sound. The changes made to the transmission for 2015 seem to have created more noise and they were not completely damped. When you shift gears the syncros that are rotating at different speeds connect and make the thud sound/vibration that is transmitted to the transmission case, then through the shifter and transmission mounts, then to the chassis, then through the cabin, then to your ears. The thud will be a little louder in cars with the PP because of the 3.73 gear.
You will typically hear the thud the loudest from 1-2 shifts, 2-3 shifts, or from neutral into any gear depending on the speed of the synchros at the time. Although you may still hear the sound from 3-4, 4-5, and 5-6 shifts, it is less likely beceause they are closer to 1 to 1 gear ratios.
Shifting technique, double clutching, or adding a transmission bushing can help a little because the synchros won't be hitting and changing speed as abruptly.
This is what I think is going on and when I took my car to the dealer they verified it.
There is technically nothing wrong with our cars. I'm sure Ford is aware and will probably try to damp the sound better for future models and probably issue a TSB if they come up with a feasable solution to quiet the sound.

Thanks...I really dislike the transmission, and am open to anything to try and help. You say Transmission Bushing, is that the Steeda "W" looking gizmo (very technical)

 

[Nemesys]

I keep forgetting about the thud and dont notice it until you jabronis bump this thread and I get an email about haha

































ps: nothings wrong

 

[Ryan1112]

Yes, I meant the Steeda bushing. It may help but it does nothing to eliminate the cause.

 

[Budnr22]

I have it. I am going to take the car in. Almost did it this weekend, but forgot it was Mother's Day, so my priorities were redirected.

I am a huge pain in the ass about everything and the rotation noise is by far the most annoying to me.

Will give ford a shot at fixing and then I will try the below one at a time until fixed or I will probably get rid of the car.

Fluid swap
Steeds mount bushing
Car back exhaust - I bet this does the trick
Dinomat or other sound isolation
Whiteline??
Aftermarket shifter
One piece driveshaft - will probably give up before this

If the above does not work, trade it in.

Feedback on the approach is appreciated.

 

[dwaleke]

I have it. I am going to take the car in. Almost did it this weekend, but forgot it was Mother's Day, so my priorities were redirected.

I am a huge pain in the ass about everything and the rotation noise is by far the most annoying to me.

Will give ford a shot at fixing and then I will try the below one at a time until fixed or I will probably get rid of the car.

Fluid swap
Steeds mount bushing
Car back exhaust - I bet this does the trick
Dinomat or other sound isolation
Whiteline??
Aftermarket shifter
One piece driveshaft - will probably give up before this

If the above does not work, trade it in.

Feedback on the approach is appreciated.

I haven't tested the one piece driveshaft, but I don't think any of that will help.

 

[Budnr22]

I haven't tested the one piece driveshaft, but I don't think any of that will help.

Thanks.....doubt I will get that far to be honest. I will keep the group up to speed on my results. Will take some time to work through the list.

 

[foghat]

I have it. I am going to take the car in. Almost did it this weekend, but forgot it was Mother's Day, so my priorities were redirected.

I am a huge pain in the ass about everything and the rotation noise is by far the most annoying to me.

Will give ford a shot at fixing and then I will try the below one at a time until fixed or I will probably get rid of the car.

Fluid swap
Steeds mount bushing
Car back exhaust - I bet this does the trick
Dinomat or other sound isolation
Whiteline??
Aftermarket shifter
One piece driveshaft - will probably give up before this

If the above does not work, trade it in.

Feedback on the approach is appreciated.

Ford is going to tell that is normal. The general consensus is that the thud is in fact normal.

areopaul had good results with a fluid change and trans mount bushing. But I believe he still has the thud and the bushing increased nvh considerably.

Judging by your list, you don't really care if the thud can be eliminated, you just don't want to hear it - even if it means just masking the sound?

 

[Ruby305GT]

Referencing a possible TSB for this issue:

http://www.mustang6g.com/forums/showthread.php?t=22556&page=7

I subbed, hopefully there is some info on this, for the "normal" thud everyone speaks about...

 

[EXP Jawa]

I still can't see how halfshafts would help a transmission issue. If there was a sloppy spline fit between the axles and the differential, or perhaps a CV joint with excessive lash that was contributing to the big picture, then changing to a revised shaft would improve things. But if the root of the thud is in the transmission - seeing all the claims of it being tied to shifting or clutch engagement certainly suggests that it is - then changes to the downstream drivetrain are irrelevant.

 

[foghat]

Referencing a possible TSB for this issue:

http://www.mustang6g.com/forums/showthread.php?t=22556&page=7

I subbed, hopefully there is some info on this, for the "normal" thud everyone speaks about...

I still can't see how halfshafts would help a transmission issue. If there was a sloppy spline fit between the axles and the differential, or perhaps a CV joint with excessive lash that was contributing to the big picture, then changing to a revised shaft would improve things. But if the root of the thud is in the transmission - seeing all the claims of it being tied to shifting or clutch engagement certainly suggests that it is - then changes to the downstream drivetrain are irrelevant.

I can't see it either. Imo, that whole thread was created way too prematurely. In it, it has been noted that at least two other dealers could not find reference to this mystery tsb. And even OP did not have insight into what the tsb was supposed to fix - someone just suggested it might fix the thud and the whole thing ballooned from there.

Plus someone who upgraded their half-shafts to 800lbs units posted saying they still have the thud as well.

 

[ssyellow]

I still can't see how halfshafts would help a transmission issue. If there was a sloppy spline fit between the axles and the differential, or perhaps a CV joint with excessive lash that was contributing to the big picture, then changing to a revised shaft would improve things. But if the root of the thud is in the transmission - seeing all the claims of it being tied to shifting or clutch engagement certainly suggests that it is - then changes to the downstream drivetrain are irrelevant.

This.

 

[yellowragtop]

autos and manual have the thud

I still can't see how halfshafts would help a transmission issue.... then changes to the downstream drivetrain are irrelevant.

People with 2015 mustang with automatic trans. have reported they also have the "thud"....so the thud might come from the driveshaft or anything else further back.


Sidenote: the toyota FRS/BRZ little sports car (rear wheel drive car) has a "thud" that is way, way worse than the mustang, and their dealerships escort them off the property after they come to talk about their rear axle "thud". all their cars have a nasty "clunk" sound when going from 1st to 2nd. they are all told it is normal and go back home.

 

[EXP Jawa]

People with 2015 mustang with automatic trans. have reported they also have the "thud"....so the thud might come from the driveshaft or anything else further back.

Its also entirely possible that they are chasing a different "thud". I think there is some evidence that there may be more than one NVH issue at play here - one specifically involving the MT82, the other being a coast-to-drive backlash clunk. The later could affect any of the models if it is driveshaft or axle shaft related if true.

 

[zx2reme]

Mine does it as well. I haven't had time to take it in yet, but planned to.

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