i hear and feel a thump thunk noise when driving around town or in bumper to bumper traffic on the highway. i have an auto and its mainly when stepping on the gas and around 15 to 20 mph shifting from 1st to 2nd and letting off the gas the noise and a little jerk comes into play. it sounds like my rear but some co-workers think it might be the rubber tranny mount. it only happens from 1st to 2nd (up-shifting and downshifting). all my other gears are fine while driving and also i could get around the noise by really driving careful and easing it into 1st or 2nd by driving realllly slow.
any ideas?

 

im pretty sure its normal...the rear driveshaft has a slip yoke and they can be noisy when your first starting from a stop

 

the u-joints in the driveshaft are going bad time to replace them, my truck does that to.

 

i would lube the slip yoke first, mine was doing that and i packed it with grease and no more thumping/bucking.