my LS 400 91 MODEL ENGAGES VERY FORCEFULLY ON DRIVE ALL THE TIME, FLIUD IS OK,ANY HELP?

do you meen that when you put it on drive it wants to fly of doen the road if so they all do that but when i changed my box the other day the new one does not do it i can put it in gear and it does not move until i release the brake

Hi,

If the engines cold the idle will be high so the car will want to lurch forward,if your talking of a sort of bang and lurch forward then it could be wear on the prop shaft in normal engine warm conditions due to the slack in the drive transmission.

Chips.

I think they all "thump" a little bit when you go into drive or reverse for that matter that's why you have to apply the footbrake before shifting.
It's more pronounced at fast idler speeds.
Wear factors could be worn engine or gearbox mounts or rubber propshaft bushes.

thanks for your sugestn,will try a box change and see