Replacing 1999 LS400 rear strut assemblies with acquired OEM parts.

​​​​​​As part of the process noticed 1990-1994 LS400 employs a rubber insulator at spring bottom, while 1995-2000 LS400 does not...

As the 1990 - 1994 lower spring insulator is discontinued, am seeking an alternative Toyota or Lexus part number that will work.

Anyone with suggestions on a contemporary Toyota part number?



1990 - 1994 LS400 rear suspension parts diagram depicting a second insulator at bottom of spring 48258-50010

1995 -2000 LS400 rear suspension diagram does not contain a lower spring insulator.


Spring insulator from LS460 shown..Inner diameter is too large..but same spring step


Only 5mm thick.


73.5 mm inner diameter.

Diameter of lower strut/spring perch is ~63mm


2001-2006 rear suspension depicting a secondary upper insulator or plate between the bellows and spring

The extra insulator or plate appears to contour to the coil spring end to prevent extruding the upper bellows/insulator .

On 1999 LS400, this is point where there is lack of constant tension between spring coils and upper insulator/bellows assembly...so the rubber extrudes. The top insulator is not stepped to spring end as is the lower LS460 or early LS400 insulator.

 

Is it necessary to buy the coil spring insulator when replacing the shock absorber and coil spring for the rear? I was looking at purchasing this coil spring insulator if that is the case. I was also wondering if you knew what was meant by "heavy duty" in this rear coil spring for LS400 (heavy duty). Does that mean that this particular coil spring is stiffer than OEM?

I've also been having a hard time finding replacement rear strut boots/bellow. The closest replacement that I found was the . Do you think this is okay?

@400fanboy Sorry for changing threads. I saw "heavy duty" springs on mylparts and was wondering if these were those stiffer springs that you mentioned in the other thread.

 

You should replace the insulators, yes. Spring, shock, insulator, mount. You can skip the springs if they aren't sagging\rusty; aka you don't live in the rust belt. Mine are perfectly healthy on my 98 so I've kept them.

I don't know if the heavy duty spring rates are higher in the rear. I would imagine they are, but cannot confirm.

You should stop jumping threads. Keep everything in one location.

 

The OE insulator and bellow are integrated into one part. As you can see they are very robust.So robust and thick yours might be ok.
Yes, they are expensive especially when added to other OE parts for the project. They are certainly worth the extra money as the KYB alternative is a joke in comparison.

 

Same goes for the shock mounts. I had both of my KYB mounts fail in 18 months, requiring me to rebuild my front suspension effectively twice.

OEM only for the rubber bits.

 

I can’t seem to find OEM strut bellow/boot. Do you think this is a good alternative? ?

 

Hiding in plain sight...

No, the KYB part is not a good alternative.

 

I use Amayama, Lexuspartsnow, or the online parts counter for a Lexus dealership (Bell Lexus North Scottsdale, BUTLER LEXUS OF SOUTH ATLANTA) to source OEM Lexus parts.

 

@bradland I think I am having a whoosh moment, was the red box around the insulator the bellow for the rear shocks?

I was thinking that the bellow for the rear looks like the bellow for the front.

 

The OEM boots SUCK. Yes that's right, they do. Rubber does not hold up well at all maybe it's because the boots have been sitting in a warehouse for 15 years. There isn't a good alternative though.

 

I have 4 years on my front shocks, the boots still look brand new on mine.

 

They crack in cold weather.

 

The original ones on my car were fine, though you up in Alberta certainly have a different definition of cold weather than here.

 

Oddly enough Lexus labels the front a bellow and the rear an insulator.
As I mentioned above, it’s basically both integrated into one part and the front and rear look very similar just slightly different size.

 

Replaced them on both a 400 and a 430.
The originals likely could’ve been re used but that’s not really logical when replacing everything else.
Both replacement sets were in good shape out of the bag still pliable and felt like a new part.
None of them, new or old, sucked…