dnthrtme1

Hi everyone!

I havent tried to duplicate the noise, (Not sure if it always does this or not), but sometimes after driving it i'll put it in park, (leave it running) and a couple minutes later I'll get a really loud thud or bang in the back end, almost feels as if somebody backed into me.

Anyone ever have something similar to this? My automatic E brake is off during this scenario.

Chuckinnj

Check your trunk for a body (saw this on Good Fellas) and also check that the spare tire is secured and laying in the "well"...... A few questions: Do you have air suspension? What model and year LS? How does the car handle on the road?

dnthrtme1

Funny! Haha, Spare tire is tight! And it does not have air suspension. It drives excellent on the road! No noises, and it doesnt pull to either side.

Ls460kidd

Could be struts

Sodium

Wow that's a strange one. To clarify: it happens when you've been in park for a while with the engine on, or does it happen when you put the car into reverse after being parked for a few minutes with the engine on?

And you can feel a concussion or vibration in the car which coincides with the noise?

Since the body is making noise when he's parked, wouldn't it technically be a kidnap victim?

Chuckinnj

Tough one!..... But here are a few ideas:
Check the condition of the exhaust hangers and exhaust clearances...... Pull on the exhaust pipes.
Jack up the car and grab the wheel and move it back and forth/up and down to see if anything is loose.
Bounce the suspension up and down.

I am "guessing" it may be a broken strut or strut component OR the coil spring is not completely sitting in the seat.

roadfrog

Seems pretty clear it's the E brake/rear shoes. Maybe they're binding on the drum (yes we have drums on the rear for the e brake system). I would start there. The e brake system is very similar to the old school drum systems of yesteryear....springs, clips, etc

Gjohnson

Did the OP or anyone else find the cause of this issue? I am getting the same noise and it happens when the car is in park, however it also happens when the car is coming to a stop or just taking off. It seems the car mus be driven fro a little while before this occurs.

For me the issue started after I replaced the Brake Actuator. I assumed the issue was caused when my battery died in the Brake Bleed process and then not being able to complete the Brake Bleed process afterward after multiple attempts. I finally broke down and took the car to an Indy shop last week to have the brakes bleed fully, but the issues still occur.

I am a complete newbie when it comes to drum brakes, what would I be looking for if this is a binding issue?

The mechanic at the shop can't seem to determine the cause of this issue, but tends to think some thing is binding in the drive-train. It may make sense if it is the drums.

Gjohnson

Any other ideas what could be causing this? I inspected the brake drums, but that doesn’t seem to be the culprit?

The loud thud occurred again this morning. The car was warmed up after driving my son to work. I was sitting in a slow drive thru line and after sitting in the same spot without moving for a few minutes I got the loud thud from the rear.

Jaifrombmo

Solved-i have a 2007 lexus gs350 and recently noticed a slight jiggle in the front of my car just before the thud in the rear. There were two separate issues. The shaking in the front was solved by replacement of a front cv axle and control arm. When i made these repairs, .... No more shake. But the thump in the rear just after pulling off from a dead stop, was obviously still present. After reading many forums ive realized that the world is full of want-to-be mechanics who are shouting out anything. This is my second lexus gs model lexus and i had this issue with both and i am 1000% positive that to fix this issue a replacement of the "driveshaft" is necessary to overcome this issue. If there is a martys or any used parts place that guarantees their parts or supply a warranty i would highly recommend it if you dont have a lot of cash to throw around. People had me replacing mounts, brakes, struts, tightening up the spare tire ect. Finally i found out it was indeed the driveshaft. There arent many reliable sources online if any so i decided to create this one.

Symptoms range from a slight thud in the rear upon pulling off or just before coming to a stop, til it feeling to the driveshaft it beating on the bottom of the floor of the vehicle. This fix is applicable to any "all wheel drive" lexus because they have a driveshaft.
Btw my last driveshaft was 100.00 used with a warranty and the labor was under 200.00. The car drove like new again instantaneously.