ntwrkguy1

I usually frequent the GS 2nd gen forum, but my wife's parents have an issue with their '96 LS400, so I figured I would turn to the experts.

The LS400 in question has 48,300 miles on it as of yesterday. My in-laws are hearing an occasional "thunk" sound when she would brake fairly hard (why she is braking hard is another question, but I digress....lol). It doesn't do it all the time, only occasionally.

My FIL takes the car to a non-Lexus shop, and apparently, they are trying to sell him struts -- for about $1500 installed. I told him to hold off, because something doesn't sound right to me.

The car has been in FL all of its life, and has all of its original suspension, struts included. They knew the previous (original) owner, and received all of the service records from him. I haven't seen or driven this car, but I question whether the struts would make this occasional noise.

I'm going to speak to my FIL tomorrow. He's not the most mechanically inclined guy, so sometimes getting the actual facts from him are a bit difficult. But I started searching around on this forum, and came across this:

https://www.clublexus.com/forums/ls4...ock-noise.html


Would the strut rod bushings NOT make any noises when driven over small bumps? My inlaws have indicated the car doesn't make any noise until you step on the brakes, which doesn't make a lot of sense to me.

As far as the actual struts are concerned, is it a "years vs. mileage" thing as to when they should be replaced? As I mentioned, this car is under 50k, but on the other hand, is 17 years old as well. I don't want them to change the struts unless they truly need to be changed.

Thanks in advance!

LScowboyLS

strut rod bushings are the most likely cause, but several other suspension issues could cause your "thunk", such as:

● upper control arms
● lower control arm bushings
● lower ball joints
● rack end bushings
● sway bar bushings

and yes, years seem to degrade suspension parts as much or more than mileage does

get the car up on a lift and move these things around and find the slop!

ntwrkguy1

Thanks for the reply, LScowboy. Any thoughts as to why the thunking noise is so random? I would think that if a part were worn to the point of needing replacement that it would be making noise all the time?

justincook

Sounds just like what I had. I replaced lots of parts including struts... strut rod bushings finally fixed it. Look at the strut rod -- it basically controls front/back motion of the front suspension. I think the noise is dependent on how quickly you apply the brakes as much as how hard. It's just a big piece of rubber that degrades over time.

LScowboyLS

make sure when you replace the bushings that you make sure of 3 very important points:

● make sure you use real Toyota bushings from the dealership or the online parts department of a real Lexus dealership such as Sewell Lexus, Park Place Lexus, Lexus of South Atlanta, Lexus Parts Now, Carson Toyota - ALL aftermarket bushings SUCK, I don't care who makes them or how much they cost

● make sure the strut rod bushing is properly clocked, you must provide this orientation information to the machine shop or repair shop, and don't assume they know what they are doing, and would know that, they usually don't

● the final torquing down of some of these components, strut rod for example, has to be done with the weight of the car back on it, let down off jack, to be done correctly

ntwrkguy1

Good information here guys -- thanks! I'll tell them to make sure it's Toyota bushings they are using. It's likely that they will take the car to the Toyota dealer to have this done, so I'm hoping the Toyota dealer is aware of the "clocking" issue.

Is there any harm in driving the car until the repair gets done?

And one last thing -- is it only the two front strut rod bushings that need to be replaced? Or is it all four of them?

PureDrifter

iTrader: (10)

rears take much longer to die, and when they go the rear carrier arm bushing is usually shot too.

shanjam

Top wishbone ball joint/drop links?