A10 transmission loud mechanical clunk at startup

[Will2]

Had a '24 Eco and '25 GT, both did this rarely. Only if the car was warm-started (5-40min after prior driving), but not always, and never happened on cold starts.

I think it's a design issue with the trans/driveline, but that info A.alansari posted basically says Ford considers it normal operation (or they don't know how to fix it)

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[Xiaoqian]

Thanks. I will try when I get the car back. It’s still at the Ford dealership now.
for reference and for this interested, here is the clunk shot from beneath and a direct view at the back of the trans.

Seems like the sound comes from the transmission output flange. I had it repalced over a year ago because when I accelerated or deccerated the car, it had play, which caused a noise. the flange was dry and the dealer applied grease on the flange and the ourput shaft spline. I wonder if it is because the grease turns soft when the car is warmed up which causes this noise?

 

[Xiaoqian]

So, the dealer changed the A10 transmission under warranty. The trans package included botht the trans, the clutch, the oil pump etc. And the clunk/noise is still there. So it's not a mechanical problem from the trans/clutch. They are investigating:
- A software issue (car sending a wrong command to the trans at startup)
- A play in the downstream shaft, axle, bearings etc (maybe the extra load at startup is normal and something is moving that should not)
- A issue with engine/trans/diff bushings (same as above)

Would you let us know if Ford Europe has fixed this issue? And if so, how?

 

[Gurney]

Ford Europe sent an engineer who is inspecting the car as I write. Will let you know the outcome.

 

[D/\rK•650]

Seems like the sound comes from the transmission output flange. I had it repalced over a year ago because when I accelerated or deccerated the car, it had play, which caused a noise. the flange was dry and the dealer applied grease on the flange and the ourput shaft spline. I wonder if it is because the grease turns soft when the car is warmed up which causes this noise?

I had mine fixed for a clunk when slowly decelerating ,they greased the output shaft on mine and it fixed the clunk. Is yours still fixed or are you having any issues? If fixed do you consider it a permanent fix? Thank you for your time.

 

[Xiaoqian]

I had mine fixed for a clunk when slowly decelerating ,they greased the output shaft on mine and it fixed the clunk. Is yours still fixed or are you having any issues? If fixed do you consider it a permanent fix? Thank you for your time.

Yes I had mine fixed and it's been over a year. I think it's permanently fixed. But this clunk from warm startup is a separate issue, which I also have and can't figure out why it is happening.

 

[D/\rK•650]

Yes I had mine fixed and it's been over a year. I think it's permanently fixed. But this clunk from warm startup is a separate issue, which I also have and can't figure out why it is happening.

Sorry to hear that your having another issue, I hope your able to get it fixed.

 

[Junkyard Dog]

Thanks. I will try when I get the car back. It’s still at the Ford dealership now.
for reference and for this interested, here is the clunk shot from beneath and a direct view at the back of the trans.

If we are looking at the back, the rear, the tail, of the transmission, where is the driveshaft? I am having trouble getting oriented.

What is that large black metal piece with two bolt heads on it? It shifts right when you hear the clunk. That is the source of the noise.

Oh, wait, is the the front u- joint?

So the tail shaft of the trans is rotating when it is in park at start up.

 

[LouG]

I didn't think the output shaft could move in park. It's mechanically locked.
Unless that movement is when the car is shifted to drive or reverse.
The OP wasn't clear on that, just referred to start up.

 

[Xiaoqian]

If we are looking at the back, the rear, the tail, of the transmission, where is the driveshaft? I am having trouble getting oriented.

What is that large black metal piece with two bolt heads on it? It shifts right when you hear the clunk. That is the source of the noise.

Oh, wait, is the the front u- joint?

So the tail shaft of the trans is rotating when it is in park at start up.

Yes you can tell from the video that it is the trans output shaft which is rotating in park at startup. But is it normal? Anyone knows?

 

[MustangNoob]

some times I have similar sound when I start the car....it is not consistent but it depends how the car was parked before the engine is shut off (like being is a slope or release the brake and have the car "relax" before you put the handbrake)... It always feel like a "residual" torque ...like spring releasing its energy .....even sometimes when I change gear from drive to park and vise versa I can hear loud noises .....car drives fine though and no issue with transmission changes

 

[MustangNoob]

So, the dealer changed the A10 transmission under warranty. The trans package included botht the trans, the clutch, the oil pump etc. And the clunk/noise is still there. So it's not a mechanical problem from the trans/clutch. They are investigating:
- A software issue (car sending a wrong command to the trans at startup)
- A play in the downstream shaft, axle, bearings etc (maybe the extra load at startup is normal and something is moving that should not)
- A issue with engine/trans/diff bushings (same as above)

Have they looked at any TSB from ford? looks like this sound is normal.....

 

[Cipis]

some times I have similar sound when I start the car....it is not consistent but it depends how the car was parked before the engine is shut off (like being is a slope or release the brake and have the car "relax" before you put the handbrake)... It always feel like a "residual" torque ...like spring releasing its energy .....even sometimes when I change gear from drive to park and vise versa I can hear loud noises .....car drives fine though and no issue with transmission changes

It has nothing to do with that. As mentioned before here, put in in reverse for couple of seconds , before park, problem solved.

 

[Gurney]

The Ford Europe "engineer" said 'all normal' and even issued a new TSB. Unfortunately he said the "rocking at startup" is normal ... but mine don't really rock (like when you switch gears) but clunks. Anyway .... I appears I'm gonna have to leave with this.

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