Club Lexus

dirkdiggle · 09-09-08, 05:31 PM

Car is a 1992 Lexus Sc400 with 160k miles.

My rear suspension has been making noise for a month and its getting worse as time goes on!

Pretty much it is a loud Hollow Clunk noise everytime I hit a bump going 10 mph +.

I have tested the rear suspension by pushing down on each side and it seems to rebound back to normal right away.

Does this sound like worn Struts/shocks or something else??

I have looked under the car and everything seems tight...no loose sway bar or anything.

How hard is it to replace the rear struts?? I looked on here and some say it is super hard while others say its very simple!!
Do I have to remove the rear seat to get at the bolts on top of the strut??

Thanks

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TheMole · 09-09-08, 05:39 PM

Look into the wheel bearings, endlinks, or bushings in the rear.
You do not have to remove the rear seat to access the strut tower bolts. Just pull back the trim in the trunk and you should see them.

TheMole · 09-09-08, 06:22 PM

Also, found a service bulletin that may help you out:

Rear Suspension - Clunking/Rattling Noise
SUSPENSION
SU95-005
OCTOBER 20, 1995
SC 300/400

Title: REAR SUSPENSION NOISE

The rear spring bumper has been changed in production on 1995 SC 300/400 in an effort to reduce clunking/rattling noises.

SERVICE HINT:
A similar clunking/rattling type noise can be generated by an improperly torqued center support nut (27 N-m, 280 kgf.cm, 20 ft-lbs).

PRODUCTION EFFECTIVE:

Starting VINs:
JT8UZ30C*S0047966
JT8JZ31C*S0030524

Old Part Numbers: 48341-24040, 48341-24070
New Part Number: 48341-24071

dirkdiggle · 09-09-08, 06:31 PM

Here is a picture

mitsuguy · 09-10-08, 08:02 AM

just because it looks tight, doesn't mean it is...

jack up the rear of the vehicle, one side at a time (unless you have a lift)...

get the wheel of the ground, then grab the bottom of the tire and the top of the tire and try to push the top while pulling the bottom, then alternate pushing the bottom while pulling the top - what you are doing is feeling for any movement - you shouldn't be able to feel anything - it might not move a lot, but what we are looking for is a slight clunk -maybe no more than a 1/4", but it will most likely feel noticeably loose...

after push/pull up and down, do it side to side, looking for the same thing - it also helps to have someone watch the bushings and ball joints to look for movement as sometimes it may be hard to feel - grabbing a control arm or ball joint while you are pushing/pulling can be helpful in feeling smaller amounts of play somewhere...

obviously, do this with both sides - more than likely you have one or more of 14 total bushings in the rear that is loose, or one of (either 2 or 4, I can't remember) ball joints that is loose... also, while underneath there, you want to look for any rear subframe bushings that might be loose and also the bushings that hold the rear differential in place...

mitsuguy · 09-10-08, 08:04 AM

On a scale of 1-10, 10 being hardest, to replace rear shocks, I would say it's somewhere around a 4 or 5...

Unless replacing with aftermarket coils, you will need a spring compressor, then you will also need a big pry bar, all the rest of the tools are common sockets and wrenches... I did all 4 in my driveway in about an hour and a half, maybe 2 hours...

dirkdiggle · 09-10-08, 01:24 PM

I did the test you recommended and I do not have any movement when I push and pull the tires......does that mean that it is most likely my shock that is bad?? I dont think they have ever been replaced and the car has 160k miles!

which brand shock do you recommend...Monroe Sensa-Trac Strut or GABRIEL ??

mitsuguy · 09-10-08, 05:52 PM

Look into KYB's as well, but any of the above are just fine...

t70 supra · 09-13-08, 10:16 AM

hey im in milwaukee ill help u