Hello All

When driveling around time the rear of the car sometimes drops. It’s not smooth, it’s like it drops 6” in a split of a second.
Sometimes when the car are just turned off and I’m out of the car you can see the rear drop.

The Lexus dealer have changed the drive shaft, but it continue to happen.
Anybody have had the same issue and what did you do about it?

Thanks for the help!

 

I also have an '11. I was told it was just the ahc returning the set driving height for the speed. I am not totally satisfied with that answer, as I've felt the back end lower while at a stop light after having only driven a few blocks at 20 - 30mph (It wasn't in high mode when I parked, and I don't set it to lower when parked). I have also heard that, while it feels like the back is lowering, it actually the front, which goes contrary to what I am experiencing. Just a guess, but maybe there is some fluid settling/pressure build up under certain conditions. It happens infrequently enough that I just live with it, but I would also like to know why it is happening.

 

I have experienced this to some degree on my GX470, LX470, and LX570 vehicles. It typically occurs after braking to a stop, and is worse if the stop is rapid, causing the front end to "dive." At some point after stopping, the sensation is that the rear end drops. With the GX this was frequently accompanied by a noise llike a clunk.

My understanding is that all these vehicles have a slip joint in the rear propeller shaft assembly. The slip joint binds, due to lack of lubrication, or more rarely, a bent shaft. As the vehicle is braked, the propeller shaft slip joint expands or lengthens. As the vehicle settles after the stop, the shaft is supposed to shorten smoothly. If the slip joint binds, it releases quickly, and causes the rear end to drop quickly rather than smoothly. Sometimes this drop takes a while to happen; it may not come immediately after stopping, but seconds to minutes later. I have even had it delyed until I am driving off from the stop. Since I know what it is, I have chosen to just live with it.

The GX had a recall to replace the propeller shaft with a newly designed one, and it eliminated the problem for me. Greasing of this joint in my LXs eliminates the problem for a while, but it recurs. Sometimes within months, other times a year or more. It seems to depend more on mileage than time.

However, the OP has a new propeller shaft and this problem still is happening. Maybe the technician skipped the lubrication step. Or maybe the problem lies elsewhere. Just my 2 cents.
.

 

Both the 100 and 200 series have slip joints front and rear. Anecdotally, I grease the u-joints and slip joints both front and rear with each oil change, that's twice a year or about 5-6000 milord.. I've never had an issue with bind, let alone a bent shaft.

hth