Rear end driveline thump.

[Heinz5774]

Greetings all,
My first post and the only fault i have with my car (2011 GT manual 40k miles 3.55 rear end)

All BMR control arms and panhard. KONI shocks Ford Racing springs. All recent.

As mentioned there is a dull thump in the rear end over sharp edge bumps

It also thumps when i dip the clutch sometimes also it may thump on release also. This can be under soft acceleration.

I have had garages i trust go all over the rear end and the suspension is fine, the only observation was that the rubber driveshaft mount rubber seemed a bit baggy but they had no experience of these cars so it could be normal. There was no obvious lash or wear apparent.

It seems worse when cold, but that could be me.

My own research suggests possible carrier bearing but i dont want to spend a lot of cash on a possibility that may be wrong.

Any suggestions would be appreciated as it's driving me nuts and spoiling my enjoyment of an otherwise great car.

Thanks very much.

 

[hand-filer]

Did this start after the suspension upgrade? Keep in mind that the factory upper and lower arms have soft rubber bushings that are designed to absorb the transfer of noise from the suspension to the body. Parts with poly bushings not so much, they're designed to reduce deflection.

 

[chris_302]

Mine does the same, NVH increases as you mod your suspension.

 

[Heinz5774]

Thanks for that, it would be nice to think there is nothing wrong with it. I can accept some road noise but i wish it didn't sound like something was loose.
The mods were done when i got it so i have no comparison to stock . I may try replacing the stock UCA and compare as i think a lot of noise comes from that.

Thanks again.

 

[chris_302]

Thanks for that, it would be nice to think there is nothing wrong with it. I can accept some road noise but i wish it didn't sound like something was loose.
The mods were done when i got it so i have no comparison to stock . I may try replacing the stock UCA and compare as i think a lot of noise comes from that.

Thanks again.

I noticed the noise problem after i installed Steeda's UCA, I'm considering switching it out for my stock UCA.

 

[TSHOES]

Could be a couple things, could be you over axle pipes hitting your pandhard bar support. If you are running an aftermarket UCA without the Aftermarket UCA bracket, thats probably the source of the noise

 

[Famine]

Could be a couple things, could be you over axle pipes hitting your pandhard bar support. If you are running an aftermarket UCA without the Aftermarket UCA bracket, thats probably the source of the noise

If it is this, he really needs to remedy this because the car will think it is knock and pull timing.

 

[paulyboy928]

if your uca is adjustable check and make sure the lock nuts are tight.

 

[2nd gen]

Maybe consider checking sway bar bushings if its an aftermarket piece as links that are attached to the body itself tend to wear out quite fast especially if set at level 3 firmest. Grab one of the back wheels (spokes)while car is stationary and start pulling/pushing back and forth and if you hear clunking then there you go. Also if the panhard bar has heim joints and if they are worn then it can be clunking also and same technique would reveal the issue!