Clunking doring engine aceleration/deaceleration
 

Hello
Since Imported and fixed my car (from Copart, it had front collision) I noticed that i have clunking sound when engine is switching between driving and been driven (supplying torque to wheels, and wheels transferring torque to engine for braking)

Is in normal in BRZ/GT86 or do i have some problem ? I know that my transmission holder was damaged doe to forces at the crash, i change that, but engine mounts was looking normal. I did not noticed free movement in my driveshaft.

Advice?

Mine clunks going into first and second. With only 33k miles, I figured it may be normal.

Diff movement?

May also be a bushing on one of the rear suspension links.

u-joint, backlash, motor mount, suspension bushing or could be completely normal

Manual transmission or automatic?

Where does it sound liked the clunking is coming from?


humfrz

Manual

Its hard to say from where. It's like where is slack between motor and wheels, so it has backlash, that cause this behavior. I don't know is it normal or not. It can be so many things in the system, while i know that my suspension is rock solid, i just get my car checked.so no movements in the joins.

It is impossible to make gears without a backlash just question how low that is from factory.

As example, if you are on low incline, and you release clutch ( no gas pedal), car can stat jerking because of this slack, off course it not a problem since I am solving this with clutch application, just wondering should i be concern or not.

Back in the day, I would have called that you had a universal joint in the driveshaft that was going bad.

However, since you have covered that, I would guess that you either have a rear axle joint that is bad or a rear axle nut that needs to be tightened.

Those are my best guesses for the day ...... ;)



humfrz

The loose axle nut makes a glassy, high-pitched 'tink' sound.

get a video of it and post it

https://vocaroo.com/i/s1QQNzjjcTVx

It is best hear from 24s mark. I just want to know is it normal.

It was in first gear stooping starting car, so torque is transferred back and fourth between engine and wheels.

Does your sound the same ?

Hard to tell from your sound clip. It sounds to me like you are mixing a drink instead of driving a car. My car is a 13' with 60k miles. No clunking.

If you fold down the rear seat is it more noticeable? I'd check the diff bushings. There is one on the nose of the diff too. I'd pull up a diagram of whatever you are inspecting and make sure all the components are there. They could have missed a spacer or sleeve that is causing excessive movement.

Can you post a youtube video so we can see how your driving your car. That will help. To me that sounds a little weird like you have something going on but I would like to see another video. go to a parking lot and have a passenger hold the camera out the door under the car. Once again I cant confirm it from the sound clip but it does sound weird. like something is loose

That's normal. There's some backlash in the differential which combines with windup from the squishy mounts. It slaps around the clutch friction disk when you release it in first and reverse. Higher gears don't multiply the effect as much. As long as the diff runs quietly, all is fine.