Clunk in rear during initial acceleration

[bmcnichols]

I have a pronounced clunk noise when power is first applied to the rear drive train in both drive and reverse. It appears to be fine once under power and accelerates normally and I dont feel any abnormal vibration. I put the vehicle up on my lift today and thought I might find a bad rear bearing on one of the wheel hubs, but they both appear to be to tight when shaking the tires. There is some backlash on CV joints, but I wonder if that is normal play. I have approximately 45K miles and tires, brakes, wheels are all in good shape. Does anyone have any idea what I should try to investigate next?

 

[X.l.r.8]

There’s a connector between the motor and transmission that’s possibly getting worn.

 

[bmcnichols]

Is there any way to check it? Is it like a CV joint?

 

[X.l.r.8]

No it’s like a collar connecting the 2, like the torque tube to transmission connector in a Porsche 944. Only way to check is to drop the motor/transmission. Not the worst but far from ideal

 

[glight2000]

I had the clunk before and eventually tracked down the culprit: it was a loose object in the trunk rolling around when I accelerated. The object was actually a CAN Jr.

I put the CAN in a small cardboard box and cured the clink.

I hope you have the same “problem.”

 

[X.l.r.8]

I had the clunk before and eventually tracked down the culprit: it was a loose object in the trunk rolling around when I accelerated. The object was actually a CAN Jr.

I put the CAN in a small cardboard box and cured the clink.

I hope you have the same “problem.”

That would be the best result ever.

 

[bmcnichols]

Thanks for the tips. I will try the empty truck solution before dropping the motor / trans.

 

[hcsharp]

I had the clunk before and eventually tracked down the culprit: it was a loose object in the trunk rolling around when I accelerated. The object was actually a CAN Jr.

I put the CAN in a small cardboard box and cured the clink.

I hope you have the same “problem.”

The best place I've found to store the CANs is between the seats. Pull it out by the draw string. That way you don't even have to open the trunk to start charging. If your legs are short and you have to adjust the seat too far forward then it may not work so well. Works best with the 2.5 seats but the 1.5 seats will also hold them.

 

[Herbie65]

i have the same issue, any thoughts? Looks there is play on the differential or transmission.

 

[einhalv]

I normally experience a "clunk" when driving slowly and changing from driving to regeneration or vice versa. I can't tell from your video if this is the same clunk as yours, but to add a data point, this is the feedback that i got from the SC after they conducted a test drive:
"The clunking is in the differential and is in all roadsters. Completely normal and as designed. If the customer feel that it is
excessive we will have to replace the engine or at least the differential, but there will still be clunking thug maybe a little
less, i have not heard a new differential in the roadster so i do not know how a new one sound but i have spoken to the
manager who replaced a lot of engines as customer was complaining, but found out the new ones was the same."

 

[jason.tv]

normal; I assume it's normal as I had same issue.

 

[Steve in SLO]

Here’s another possibility. Look at post #2 by jason.tv:

is it normal for the clunk noise from rear when accelerating/deaccelerating

when the speed is slow , I can get the noise if i accelerate and deaccelerate . Here is the video. is it normal? did you roadster have it? or anyway to fix it?

teslamotorsclub.com

I have the same clunk in mine, and am going to check next time I have the car in the air.

 

[Peter.h]

I remember having a very loud clunk on my 2.5 but it’s much less pronounced on my 1.5. I wonder if others have experienced the same?

 

[driver_EV]

Got the noise on mine. Its been there a long time, perhaps it was always there. I like the "normal" explanation.