Manual Trans. Thud when shifting

[fogus]

We aren't talking about driveline lash! This is a completely different sound. Damn, this is so frustrating. I've had plenty of RWD manuals and none did this. I still have my 2010 GT and it does not do this.

Yeah. I think you're right. When I first got this car it was my first RWD car and first manual. I got lash a lot because I couldn't control the clutch well. Now I don't get it anymore. I get thud though.

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[FordTechOne]

We aren't talking about driveline lash! This is a completely different sound. Damn, this is so frustrating. I've had plenty of RWD manuals and none did this. I still have my 2010 GT and it does not do this.

How do you know it's not driveline lash? Did you place the car on a loaded dyno and observe the driveline as the vehicle was accelerated? Did you use a vibration analyzer or chassis ears to determine which component was inducing the clunk/noise? A 2010 GT is a completely different car. You need to compare apples with apples.

 

[fogus]

How do you know it's not driveline lash? Did you place the car on a loaded dyno and observe the driveline as the vehicle was accelerated? Did you use a vibration analyzer or chassis ears to determine which component was inducing the clunk/noise? A 2010 GT is a completely different car. You need to compare apples with apples.

Uh, you did just say it was a normal characteristic in almost all RWDs.

Now a previous gen mustang is an invalid comparison?

 

[FordTechOne]

Uh, you did just say it was a normal characteristic in almost all RWDs.

Now a previous gen mustang is an invalid comparison?

Yes, because a completely different car is going to have different characteristics. It's not that hard to understand.

All RWD cars will have more driveline lash than a FWD car because they have a longer driveline with more components. The extent of the noise/lash is entirely dependent on the model.

 

[WeinerDog]

Yes, because a completely different car is going to have different characteristics. It's not that hard to understand.

All RWD cars will have more driveline lash than a FWD car because they have a longer driveline with more components. The extent of the noise/lash is entirely dependent on the model.

Do you have one of these cars and/or have you heard in person what we are talking about?

 

[WeinerDog]

How do you know it's not driveline lash? Did you place the car on a loaded dyno and observe the driveline as the vehicle was accelerated? Did you use a vibration analyzer or chassis ears to determine which component was inducing the clunk/noise? A 2010 GT is a completely different car. You need to compare apples with apples.

How much of this thread have you read? It's not lash because it happens BEFORE you engage the clutch/transmission. It happens clutch IN...no way for lash in that condition. Unless we differ on the definition of "lash".

 

[FordTechOne]

Do you have one of these cars and/or have you heard in person what we are talking about?

Driven plenty of them. The concern can mostly be heard when taking off from a stop in first gear and then allowing the vehicle to coast down. The clunking/lash can be felt as the resistance transfers between the wheels and engine. It can also be heard when shifting between gears at lower speeds.

Lash certainly CAN happen clutch in as well, because at that point the wheels are driving the axles/differential/driveshaft/output shaft instead of the other way around.

 

[WeinerDog]

Driven plenty of them. The concern can mostly be heard when taking off from a stop in first gear and then allowing the vehicle to coast down. The clunking/lash can be felt as the resistance transfers between the wheels and engine. It can also be heard when shifting between gears at lower speeds.

Thanks for the clarification. You are not talking about what we are talking about! Totally different issue. What you are talking about is not an issue IMO and I agree is a normal attribute with a RWD setup.

 

[FordTechOne]

Thanks for the clarification. You are not talking about what we are talking about! Totally different issue. What you are talking about is not an issue IMO.

Can you post a video of what you are referring to? Might help to clarify for everyone.

 

[Hwy1]

Can you post a video of what you are referring to? Might help to clarify for everyone.

It's this kind of conversation that will get us to finding out what it is...
I don't see anything wrong with anyone's help here, very hard to analize a noise issue.
Just want to thank everyone for trying

 

[fogus]

Yes, because a completely different car is going to have different characteristics. It's not that hard to understand.

All RWD cars will have more driveline lash than a FWD car because they have a longer driveline with more components. The extent of the noise/lash is entirely dependent on the model.

One minute almost all RWD card have the characteristic and it's almost impossible to engineer around and we're dull for not realizing this and accepting that it's not a bug, the next minute another V8 RWD car driver wouldn't experience it and we're just dull for not understanding how different cars have different characteristics.

Do you interact with customers?

 

[SLA]

One minute almost all RWD card have the characteristic and it's almost impossible to engineer around and we're dull for not realizing this and accepting that it's not a bug, the next minute another V8 RWD car driver wouldn't experience it and we're just dull for not understanding how different cars have different characteristics.

Do you interact with customers?

It was just clarified a few posts ago that the noise he was describing is not the issue at hand.

 

[fogus]

It was just clarified a few posts ago that the noise he was describing is not the issue at hand.

Agree. I'm just confused by this interaction.

Clutch in and at a standstill; not drive line lash. Drive line has no kinetic energy at a standstill, so can't lash you. Got it.

I'm going to make a vid tonight.

 

[BV600]

I installed the steeda trans bushing insert a couple days ago and haven't had the trans thud since. I need a little bit more time to verify it though.

 

[CB]

You seem to be the only person who actually understands that that this is a NORMAL characteristic of almost all RWD vehicles. Seems that a lot people on here who hear ANY noise and assume their vehicle is going to blow up :headbonk:

S550 Mustangs use a 2 piece driveshaft to optimize driveline angles and minimize vibrations, and they do a damn good job of it. The downside is additional driveline lash caused by the long 2 piece driveshaft and center support bearing.

If you want to eliminate a lot of the driveline lash and bangs/clunks, then get an aftermarket 1 piece aluminum driveshaft. Vibrations may increase slightly, but you will have less rotating mass and much less driveline lash. My 04' Cobra came from the factory with a massive 1 piece aluminum driveshaft, and I wouldn't trade the slightly better NVH for a 2 piece unit.

This is a crock of horse shit. I've owned many rwd vehicles over the years, even as old as a Studebaker pick up truck. None of them did what these people on this sight are describing.

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