Hi,

I have a few questions about the rear suspension... I've already replaced the rear strut rods (#9) with new OEM, the UCA's, Adus 505's, Adus 583's, sway bar links, and struts... How common is it for the inner bushing on LCA number 2 to let go (#10) and LCA number 1 (#8) as a unit to let go? Also, when replacing the rear sway bar bushings with new original OEM's, is it wise to lube the new bushings, or are they best installed dry? My 91' has 96k miles on it...

Thanks

 

wouldnt hurt to grease them. dang low mileage LS!

 

with bushings, the ones in worst condition get the most wear. do you have reason to believe they are bad? sounds like the new bushings you installed might have took a toll on the remaining originals.

 

I'm getting some strange sounds at speeds below around 30mph over the tiniest bumps. Sometimes a very mild clunk, at other times, almost a scrunching sound. Typically only happens after the car has been driven 5~10 miles or more. Once warmed up, it may do it on what appears to be perfectly flat pavement. Doesn't do it at higher speeds or over significant bumps. Also tends to have the scrunch sound more when cornering at slow speeds... Both sides are making the noise, which is why I asked about lubing new OEM sway bar bushings. I did lube them when I put them in and since this is the only component that spans across from one side to the other, I thought maybe I could have caused the problem by lubing them and instead should have put them in dry...

I think you may be right... The only parts in the whole rear suspension left to replace are the #8 LCA in the pic and the #10 bushing, which is the other half of the Adus 583 kit that I already have but didn't install... I might as well replace those remaining parts and see if that solves the problem.

Thanks

 

Hey-

Sounds as if you have a great LS400 and are really taking good care of it!

I have 320k on my LS400 (we have owned it since new actually) and one part that gave me some trouble up front and was a little difficult to diagnose were the upper spring mounts. I don't know if the sound you're hearing sounds as if it's "inside" the car (the mounts in the rear are under the rear shelf) or what, but the rear strut mounts could be something else to look into. I replaced all four on my car a while back with some KYB ones. No problems since... You might be able to remove the parcel shelf and squirt some WD-40 or something into the top of the mount to see if that temporarily abates/affects the noises. Could help narrow down what your problem may be.

That said, the symptoms you describe sure do sound like they could be the sway bar bushings. Those are much cheaper/easier to remove, grease and replace.

Good luck!

(btw, in case it helps, attached is a more detailed part breakdown diagram similar to the one you posted)

 

where'd you get THAT diagram?

 

Thanks for the responses... Excellent diagram of the rear suspension components! I'll check out the rear struts. I have all new struts & springs, but it doesn't mean they can't have a problem or be defective (Arnott's)...

 

Thanks for the details. What symptom were you experiencing before you changed the upper spring mounts ? my LS 1990 has about 175k miles and it sways a lot, as well as every time there's even a slightest hole or bump the rear makes a loud thump noise and the whole rear shakes as if there were no struts back there at all. It has air suspension and the rear struts are new...
thanks in advance.