Hi there I have recently picked up a 2007 LS460 which has a nasty thump when switching from Reverse to Drive, though if I go back and forth a few times it will then shift smooth with no thump.
The main reason i want to sort it is that when i'm driving along with my foot off the accelerator (driveshaft no longer spinning) then when I go to accelerate this is when I'm getting that nasty thump from the rear again, it's uncomfortable enough that i can't drive it anymore

Just wanting opinions before I go ahead and replace all diff bushings ...also the rubber flex plate has a few small cracks would that do it? Can't even find where to source a replacement.

Thank you!

 

Make sure it's not your trans/engine mounts before you do that, best to get it on a lift and have someone shift from D->R a bunch on the brakes while you watch and listen for the source of the thump

 

Unfortunately that rubber flex plate is not something sold separately. You have to buy the whole driveshaft. I'm not sure why they did this because the previous gen LS did have a separate part for it.

 

What makes you think the driveshaft stops turning when you take your foot off the accelerator pedal? When you were underneath your car did you try to turn the driveshaft to see how far the pinion turned in either direction? check the fluid?

 

When I come off the gas very lightly at any speed I can feel a rebound-like movement from beneath the car which feels related to the thump - thought it may be some sort of fuel saving feature controlled by the trans ecu while the cars coasting or am I wrong? Perhaps it's just changing gears.
It hardly matters if I come back on the throttle gently or foot to the floor I'll still get the a loud thump in the rear

I haven't spun the driveshaft or checked the fluid yet I'll get that done next

Thanks for the help forums are a great place!!