Manual Trans. Thud when shifting

[Gibbo205]

I don't have the thud, I have clunking when on and off the throttle. Drive line lash, if I take the drive shaft out u can rotate the diff back and for 3.4 inch.

I think this is what my car has!

UK Manual GT PP, so is a 3.55 Traction lok.

Car as standard brand new had a very slight thud, hard to notice infact but I am sensitive to NVH, passengers could not hear it, but it did not bother me to be honest.

Then I fitted:-
Steeda differential red bushing inserts: Thud practically gone!
Installed BMR CB005 cradle lockout: Got light clunking instead!

From speaking with Kelly and I agree what I am hearing now is what you are hearing which is drive line rash which transmits through the steeda urethane bushes through the solid mounts of the CB005 kit into the cabin.

Yes its a tad annoying, but I am learning to shift in a way preventing it when at low speeds, at high speeds it does not happen or it does but exhaust drowns it out. But CB005 and the bushing inserts make the rear-end of this car feel so much better!

The only thing I did consider, would a one piece carbon drive shaft help with the driveline rash noise which I think is the clunking I can hear that only happens upon clutch operation sometimes, mainly at low/normal speeds.

Sponsored

 

[kbow13]

I will also vouch for the red Steeda diff bushing insert. My 2016 GT pp thud is 95% gone. On rare occasions hear a faint thud. I also noticed a decrease in wheel hop, not completely gone but better. Great mod with a very affordable price!

 

[David@Steeda]

I will also vouch for the red Steeda diff bushing insert. My 2016 GT pp thud is 95% gone. On rare occasions hear a faint thud. I also noticed a decrease in wheel hop, not completely gone but better. Great mod with a very affordable price!

Glad our diff bushing inserts not only nearly eliminated the thud, but also reduced wheel hop!

 

[woofwoofdroolyface]

Just installed my diff bushings as well, thud is gone and the rear feels much less sloppy and far more stable.

 

[Genxer]

I just got back from a drive with the Steeda bushing inserts installed (red) and I am happy with the results. The rear end seems more tied down and the car is overall more balanced. That was the primary reason I did the mod. The thud isn't gone but it has been diminished somewhat. From neutral to 1st it's there slightly, but it seems like once I am rolling, the thud is less pronounced during gear changes. Shifting seems a bit smoother to me, too. Overall, it was a worthwhile mod IMO. The install was kind of a pain, as you have to drop the front subframe bolts to lower the front of it down to get in the last bolts. Right now I feel like this car is setup perfect with the few things I have done to it.

 

[kenbidwell]

Changed transmission fluid yesterday with Redline MT85. Smoother and the thud is gone going into first. Small thud when shifting from 1st to 2nd and 2nd to 3rd but much better. Can't believe that just a fluid change helped. Less noise from the transmission also. Over all a great change and fairly easy to do.

 

[PJR202]

question...


I have the thud. Is this something actually causing damage?

 

[redline727]

Only to your ears when you jab a screwdriver in them if the noise frustrates you enough...lol

question...


I have the thud. Is this something actually causing damage?

 

[PJR202]

Only to your ears when you jab a screwdriver in them if the noise frustrates you enough...lol

I haven't decided how much it frustrates me just yet..lol


Can someone give me the dumbed down version of what's actually occurring when this happens? I know people are saying get these differential bushings, but I'm not diff savvy. What causes the thud?

 

[redline727]

I haven't decided how much it frustrates me just yet..lol


Can someone give me the dumbed down version of what's actually occurring when this happens? I know people are saying get these differential bushings, but I'm not diff savvy. What causes the thud?

There are a couple guesses, but most feel it's a combination of the soft durometer of the sub frame and differential bushings. Basically when you shift there is torque transfer sent from the transmission through the driveshaft into the rear differential, that torque causes movement of the differential housing through the soft bushings and the rear subframe and those soft bushings into the body of the car. That movement can be felt and heard as the "thud". People are reporting with higher durometer bushings or bushing lockout kits the movement is stopped. So therefore eliminating or reducing the thud. But also undertsand you're not stopping that torque coming from the transmission by doing mods like that. You're just making the driveshaft, differential, subframe, and axles absord it now since it will continue to be transferred all the way till it escapes at the tires/ground. Which is mainly why mods like this are done. To put the most torque to the ground and it not be lost through soft bushings and cause wheel hop and loss of traction. Downside to this...your moving mechanical parts take more of a beating, like driveshaft, diff, and axles... The real reason for making the rear more rigid should be for performance, not to eliminate a sound. Bc when you do it in the name of performance you are prepared and except it more if you break something. Hence the term, "you have to pay to play."

 

[CB]

Here's what the dealer will do about the thud. They'll take your car to lunch, they'll beat it and over rev it and do burnouts. Then they'll tell you the thud is a characteristic of the vehicle. Then they'll tell you to go home.

 

[EchoTango]

Had the thud but gone now. 5700.

 

[PJR202]

There are a couple guesses, but most feel it's a combination of the soft durometer of the sub frame and differential bushings. Basically when you shift there is torque transfer sent from the transmission through the driveshaft into the rear differential, that torque causes movement of the differential housing through the soft bushings and the rear subframe and those soft bushings into the body of the car. That movement can be felt and heard as the "thud". People are reporting with higher durometer bushings or bushing lockout kits the movement is stopped. So therefore eliminating or reducing the thud. But also undertsand you're not stopping that torque coming from the transmission by doing mods like that. You're just making the driveshaft, differential, subframe, and axles absorb it now since it will continue to be transferred all the way till it escapes at the tires/ground. Which is mainly why mods like this are done. To put the most torque to the ground and it not be lost through soft bushings and cause wheel hop and loss of traction. Downside to this...your moving mechanical parts take more of a beating, like driveshaft, diff, and axles... The real reason for making the rear more rigid should be for performance, not to eliminate a sound. Bc when you do it in the name of performance you are prepared and except it more if you break something. Hence the term, "you have to pay to play." ��

Thanks so much for the detailed reply. It just feels annoying and unnecessary. Even when already in gear if I blip the throttle that slop is there. I'm not drag racing and most of my fun is just simple acceleration and corners, but it just seems like something they'd have found a way to do better. As long as it isn't causing damage I guess I can live with it--it just makes for a rough ride. Obviously a person doesn't buy a 435hp car for a smooth ride though. OK I'm done whining.

 

[PJR202]

Had the thud but gone now. 5700.

I wonder why. Do you think the bushings are hardening or something?

 

[skytop1]

The shift thud has slowly returned. I guess I will have to live with it but it is unacceptable. No more Mustang's in my future.

Sponsored